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Subaru Forester (up to 2005)

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Comments

  • ballisticballistic Member Posts: 1,687
    Juice says, "We should keep one possibility in mind - the EPA does on occasion revise it's figures when it finds that its numbers are off. Often it'll also make assumptions about a similar model getting the same mpg, and then they test it and have to revise the figures."

    An interesting possibility that could, if it happens, answer the mystery of the XT's unexciting EPA numbers. It would have no effect on any actual owner's actual mileage, because nothing would change except the EPA re-test and revised numbers.

    jb
  • ballisticballistic Member Posts: 1,687
    Len says "I remember from my hot-rodding days that there was a commercially made device that clamped to the clutch pedal to prevent it from going all the way to the floor. It had a small pad at the bottom that would contact the floor to stop the pedal travel. It was adjustable..."

    No kidding...darn, I was going to patent my 2x4 block of wood. Somebody always beats me to the brass ring. But you've validated the concept, so at least it wasn't totally wacky.

    jb
  • leo2633leo2633 Member Posts: 589
    If I can find some of my old books, I'll try to get a brand name or something. I distinctly remember the photos of the contraption.

    Len
  • subearusubearu Member Posts: 3,613
    So, what we need is for someone to drive their XT in city/stop/go mileage and another to do a highway trip. Both easy to do with minimum time.

    City trip: fill tank completely (with first 'click' of fuel nozzle). reset trip odometer. Drive somewhere where you can get into a decent stop/go pattern (lots of traffic lights, speeds < 50mph). Probably need at least 20 miles driven to ensure that at least 1 gallon will go back into the tank. fill tank and note gallons required to fill. could repeat a few times to establish a trend.

    Highway trip: fill tank completely (with first 'click' of fuel nozzle). reset trip odometer. get on the highway or some other road allowing minimum speeds of 55mph. Don't drive more than 65 mph, at least for this first test. Again, probably need at least 30 miles driven to ensure at least 1 gallon is used. fill tank and note gallons required to fill. also could repeat a few times to establish a trend.

    Any takers? Even with a green engine or one with < 1000 miles.

    ;-)

    -Brian
  • joseph50joseph50 Member Posts: 235
    In a plastic "milk crate" thingy from Staples office supplies:empty gallon gas can; jumper cables; foot pump for tire; a pump to pump gas from one car tank to another; a fold up plastic poncho; a fold up silvery windshield guard that goes on the *outside* of the windshield (wings closed down by windows on front doors) that protects against sun in summer and ice build up in winter; pair of work gloves; dayglow orange foldup plastic spread; plastic bag; car cleaning/waxing stuff.

    In a clear plastic storage container, also from Staples: blanket; First aid kit - the best CR recommended; reference books for work; thermos jug and small plastic water bottle.

    Smallish plastic tool box from Pep Boys with flash light, tools, plug-in light, duct tape.

    Small duffle bag with an extra change of clothes and shoes for casual and semi-casual changes.
    All containers neat, straight across and immediately available upon opening of the back --and not deep so when I fold down the back seats I can add some really important cargo, like golf clubs.
  • leo2633leo2633 Member Posts: 589
    Jack,

    It was called a "Hays Dzus pedal stop". To quote the caption under the photos in this book, "it's used to limit pedal travel to no more than is necessary to gain full clutch disengagement-a very important consideration in drag racing. The device is fully adjustable and can fit numerous applications."

    By the way, the book is called, "Clutch and Flywheel Handbook", by Tom Monroe, published by HP Books, and is dated 1977. It has more about clutches and the like than you'd ever want to know. (It came in handy when I was working on my 1970 Mustang Mach 1.)

    Len
  • ducktapeguyducktapeguy Member Posts: 115
    In the interest of settling this discussion, I will volunteer to take somebody's new XT and drive it around and carefully record the milage. I'll even chip in for gas. anybody?

    joseph50,
    how do you keep all that stuff in the back? doesn't it shift around all over the place? I usually carry stuff under the floor, in the center of the spare tire well if it'll fit, or under the passanger seat. I used to carry a lot more (more than you even) but I didn't like having everything move around. Now i just keep a couple of old backpacks strapped onto the back of the front seats to hold some stuff.
  • joseph50joseph50 Member Posts: 235
    "how do you keep all that stuff in the back? doesn't it shift around all over the place? I usually carry stuff under the floor, in the center of the spare tire well if it'll fit, or under the passanger seat. I used to carry a lot more (more than you even) but I didn't like having everything move around. Now i just keep a couple of old backpacks strapped onto the back of the front seats to hold some stuff."

    I appreciate your response. (I keep extra quarts of emergency oil containers and such in the spare tire well, which I did not mention. I like to feel I can be of help to a stranded traveller, even if it be myself.)
    As I tried to convey, the containers I mentioned fit snug in a line right across the back, nearest the back door - on the fuzzy, non-skid carpet material. No movement, no problem.
    The rubber cargo mat I placed onto the folded down back seats to receive a whole load of extra cargo. (I have no need of back seating.) The fit of the mat in a place it was not designed to be in is not perfect, but it will do.
    Cheers.
  • once_for_allonce_for_all Member Posts: 1,640
    congrats on your XT!. I think the mpg discussion is fairly basic--the turbo stuffs more fuel and air into the engine at all rpms, and it acts like a much bigger engine. With the WRX and STi, the turbo range is later so you don't see an impact. Just because there isn't a "positive" boost at some rpms doesn't mean there isn't more fuel getting stuffed in.

    John
  • ateixeiraateixeira Member Posts: 72,587
    One thing I've noticed is that after you reset the ECU, the engine runs rich for about a tankful, sometimes two. I lose about 2mpg from my average usually.

    So if we measure mileage with a green engine and an ECU with 12 miles of experience, then the numbers will still seem low.

    -juice
  • lbhaleylbhaley Member Posts: 91
    Jack,
       Have you asked your dealer to adjust the take up on your clutch? As I have said, my XT MT clutch takes about half way up and is nicely progressive. An adjustment would seem to be a much better solution than trying to cluge something to limit travel.
     -les
  • ballisticballistic Member Posts: 1,687
    joseph carries a "fold up silvery windshield guard that goes on the *outside* of the windshield (wings closed down by windows on front doors)"

    No doubt that blocks even more heat than an inside shade, but wouldn't yours get as dirty as your windshield?

    jb
  • ballisticballistic Member Posts: 1,687
    Len writes "It was called a "Hays Dzus pedal stop". "

    I ran a Google search on that, and came up empty. Evidently nobody carries it anymore. However, it won't be difficult to cobble together something that will work.

    Thanks.

    jb
  • maverick1017maverick1017 Member Posts: 212
    in a collapsable milk crate type container (from Wally mart!)roll of papertowl, air pump, package of Mother's bug & sap wipes, package of Quick detailer wipes, bottle of windex, some shop rags, Coleman duel purpose flashlight/flurecent light, fold up rain jacket and pants, fold up poncho. in another collapsible milk crate type container I have, fleece travle blanket, a few MREs, a travle tool case, a bottle of Fabreez, and spare batteries. On the left cubbie, a first aid kit, and a very small bottle of Mother's Cali Gold wax. In the right cubbie, a bottle of tire inflator/sealer, tire presure guage with bleed valve, and an emergency work light with magnetic backing. In the spare tire tray I have jumper cables, quart of motor oil, quart of tranny fluid, flares, and light sticks. Cubbie to the right of that I have utility knive, electric tape, and double sided tape. Factory jack storage area I have pair of Mechanix work gloves, bag of wet wipes, and packages of spare bulbs for every light on the car.

    This is only the warm weather stuff, I usually add a mummy sleeping bag rated to -20 degrees, heat packs, shuvle, kitty litter, ski pants and blizzard jacket for the winter. (but I do take out the windex, wax, detailer wipe, bug & sap wipes, and other warm-weather-only stuff)

    I also carry a flashlight mounted to the floor on the drivers side and another one on the passenger side as well as a spare one in the glove compartment. I also have a fire extinguisher mounted to the floor on the driver side.
     
    And I still get over 25 mpg in combined driving using only regular! Woohoo!

    Mike

    P.S. you know, I never though I carried that much stuff untill I had to write this.
  • joseph50joseph50 Member Posts: 235
    "joseph carries a "fold up silvery windshield guard that goes on the *outside* of the windshield (wings closed down by windows on front doors)"
    No doubt that blocks even more heat than an inside shade, but wouldn't yours get as dirty as your windshield?"
    jb

    Windshields mostly get dirty when driving.
    Not having a garage, the really nifty thing about this thing is being able to instantly remove 6 inches of snow and ice from the windshield simply by opening both my front doors and taking the cover off.
  • ateixeiraateixeira Member Posts: 72,587
    Let's see, I have a blanket, a spare jacket, a bottle of water, a tire guage, plus I store the rear head rests when the kid seats are in place, that makes visibility incredible.

    Everything goes under the rear cargo floor.

    -juice
  • ballisticballistic Member Posts: 1,687
    John says, "!. I think the mpg discussion is fairly basic--the turbo stuffs more fuel and air into the engine at all rpms, and it acts like a much bigger engine. With the WRX and STi, the turbo range is later so you don't see an impact. Just because there isn't a "positive" boost at some rpms doesn't mean there isn't more fuel getting stuffed in."

    I'm about ready to give up. We are simply not communicating. Every response such as yours is overlooking crucial elements of my thesis.

    What you say is true, but inapplicable. Consider just one example: You have an XS 5-speed Forester, I have my XT. We're both driving side-by-side at any given highway speed. Your XS has to produce (say) 50bhp to overcome all drag factors and maintain speed. My XS has to produce the same, identical 50bhp to stay exactly even with you. Induction airflows and fuel delivery rates are DIRECTLY proportional to power demanded, REGARDLESS of whether my engine is turbocharged or yours is not. Even if my turbo is producing boost, my throttle will be opened less than yours; the total airflow past my less-open throttle, and the quantity of fuel injected into it, will be the same as yours. The manifold vacuum downstream of our throttles will be roughly equal - despite that my engine happens to have a turbocharger that might be pressurizing the plumbing upstream of the throttle butterfly. Despite all assertions to the contrary, the turbo is NOT the final determinant of how much air (or fuel) the engine ingests - the throttle is!

    Given idential driving conditions, your XS engine and my XT engine will be producing nearly identical power outputs and will be consuming nearly identical fuel quantities. Unless my XT has appreciably more total drag and friction than your XS (which it doesn't), or is appreciably less efficient at converting chemical energy in the fuel to mechanical energy than yours, you and I ought to get nearly identical MPG driving side-by-side. No amount of misguided references to the turbocharger alter this.

    Extrapolate that to the EPA tests, which likewise call on my XT to produce, at any given moment, roughly the same power (hence air and fuel flows past the throttle and into the engine, regardless of whatever the turbo is doing upstream of the throttle) as your XS. Since the EPA tests will never call on my XT to produce any more power (or induction airflow rates, OR FUEL FLOWS) than your XS to perform any aspect of the tests, your comments simply do not apply.

    Then add in the fact that your XS has fixed valve timing (so that its valve overlap is at best a compromise at most speeds and loads, and is sub-optimal at most) whereas my XT has variable timing (continuously optimized for all conditions, including light power demand) and other efficiency-enhancing improvements, and tell me why I should do appreciably worse than you under the same exact driving conditions, using the same exact amount of power? Responses that fail to account for the unarguable facts will no longer get responses from me.

    JB
  • ballisticballistic Member Posts: 1,687
    les suggests, "Have you asked your dealer to adjust the take up on your clutch? As I have said, my XT MT clutch takes about half way up and is nicely progressive. An adjustment would seem to be a much better solution than trying to cluge something to limit travel."

    I'll try that before futzing around, but when described the clutch travel and engagement to my salesguy while he was completing the delivery paperwork, he called the service people; they told him there were no adjustments which would affect what I described. Hard to believe, but maybe hydraulic clutch actuators don't have the same sort of adjustment ranges that previous ones did. Before too long I'll get underneath and take a look myself.

    -jb
  • ateixeiraateixeira Member Posts: 72,587
    Jack: we are purposely trying to drive you nuts. It's part of our strategy to get even since you have a much quicker Forester. ;-)

    -juice
  • ballisticballistic Member Posts: 1,687
    <but wouldn't yours get as dirty as your windshield?>

    Joseph replies, "Windshields mostly get dirty when driving."

    Well, yes, but it stays that way when you stop. Or do you wash your windshield before attaching the outside shade?

    jb
  • ballisticballistic Member Posts: 1,687
    Juice fesses up: "Jack: we are purposely trying to drive you nuts..."

    It's working. I've always though I communicated reasonably well, but I've clearly lost that ability.

    jb
  • steverstever Guest Posts: 52,454
    You carry more stuff than I have in my garage!

    ;-)

    Steve, Host
  • maverick1017maverick1017 Member Posts: 212
    you are probably right, but I have this need to be prepared for anything, no matter if I am just going to the mall on a sunny sunday afternoon. One never know when mother nature will smack you in the face and call you names a sailor would be ashamed to utter. hahaha. Okay I am obsessive and compulsive, realization is the first step towards recovery, (un)fortunatly for me I rarely get past that first step, hahaha :)

    Mike
  • maverick1017maverick1017 Member Posts: 212
    Not mine, but still sad.

    The bright part, they are parting it out on ebay! if you drive a 98-00 check it out:

    http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item- =2420946451&category=33642
  • tkevinblanctkevinblanc Member Posts: 356
    The simplest explanation is that the EPA's mileage test for the XT was wrong. I have no problem at all accepting this. Only time will tell.

    It's also likely that folks' mileage experience with the XT will be different: there's more power available, some will use it, some won't. So time might not tell that much.

    You are also assuming that the variable valve timing on the XT engine is tuned for efficiency. It might be tuned for performance. There's no reason to believe that Subaru isn't going for the gusto here, regardless of any marketing hoo-hah they distribute.
  • steverstever Guest Posts: 52,454
    I let the 24 hour Wal-Mart down the road warehouse all that stuff for me :-)

    Plus I figure if I do break down, some nice guy like you will come along and give me a jump. Happened twice last winter at the ski hill.

    Steve, Host
  • kenskens Member Posts: 5,869
    Let's see:

    Bungee cords
    First aid kit
    Meguiar's Quik Detail Spray
    Cotton Towels
    Flashlight
    Car glass cleaner

    Ken
  • kenskens Member Posts: 5,869
    jack,

    I enjoy reading your responses, but your heavy use of quotes makes it difficult to distinguish your answers from those of other posts.

    May I suggest you use the HTML tag to italicize the quotes? Just place [I] before and [/I] after (but replace the "[" and "]" with "<" and ">" respectively) your quotes.

    Another handy one to know is to replace the "I" with "B" to bold. Both can also be used in combination as well.

    Ken
  • ducktapeguyducktapeguy Member Posts: 115
    maverick,
    "I also carry a flashlight mounted to the floor on the drivers side and another one on the passenger side as well as a spare one in the glove compartment. I also have a fire extinguisher mounted to the floor on the driver side."

    How do you find all the room to mount that stuff to the floor? I've tried mounting stuff like that, but I can't find a position where it doesn't get in the way at some point. 3 flashlights? You're almost as bad as I am. I have 1 in the glove compartment, 1 hanging from the passenger side sunvisor (a small solar powered one) one in the center console, and in the tool area under the trunk. And I'm still trying to mount a rechargable somewhere in the passanger compartment somewhere, probably under the passanger seat since the drivers seat has the subwoofer.

    joseph50,
    have you ever tried putting velcro on the underside of the boxes? Since you have it sitting directly on the carpet, you wouldn't have to squeeze everything in there to make it stay. I use velcro to hold my power inverter onto the side of the transmission hump when I use it. I also saw these cool L-shaped blocks with velcro on it at a jeep dealership. Serves the same purpose, but you can position it to hold different sized loads.

    ballistic,
    I understand your argument, but if that were the case, wouldn't all cars get roughly the same milage? Assuming the coefficient of drag isn't that much different between similar cars? So say for a midsize SUV, no matter if it had a 4 cyl or V-8, shouldn't it get the same milage since the energy used to propel the car should be the same? Let's compare a 4cyl honda CRV to a BMW X5 4.8L. So assuming it takes 50 hp to travel at 65 mph, Even if the 4 cyl is in a more efficient powerband, is it twice as efficient? I doubt it. There must be some differences when they test the milage, i dunno how though
  • ballisticballistic Member Posts: 1,687
    After all the nonproductive back-and-forth, I actually have (since the beginning) had two possible explanations in mind for the XT's unexpectedly poor EPA results when compared to the X/XS, and even compared to the WRX or STi.

    First: There is one and only one "ideal" fuel-air ratio for an Otto-cycle (4-cycle gasoline-burning) engine. The stoichiometric (or ideal) air/fuel ratio is about 14.7:1 (air to fuel, by weight). It is well established that any air/fuel ratio that departs from this theoretically-optimal rate (either leaner or richer) will diminish any given engine's energy conversion efficiency, leading to less horsepower production per unit of fuel combusted.

    I am guessing that in re-tuning (DE-tuning) the STi engine (essentially a race-car engine on the street) for the XT, Subaru intentionally decided to emphasize long-term reliability in exchange for slightly worse combustion (and energy conversion) efficiency - and, unfortunately, gas mileage. To accomplish this, they apparently deliberately chose to program the ECU for a richer-than-optimal ratio of fuel to air. Especially in boosted engines, the "quenching" phenomenon of supplying more fuel than the available oxygen can fully oxidize has the effect of reducing peak combustion temperatures pressures and downstream exhaust temperatures. While this would only be achieved, unfortunately, by increasing the amount of fuel consumed per unit of power produced, Subaru apparently decided that (for the Forester XT's intended purpose) this tradeoff was worthwhile. It is not, after all, meant to be a thinly-disguised race car, as the STi is.

    The other explanation is that (for the exact same reliability-enhancing objective as above) Subaru may have decided to program the ECU to provide slightly less spark advance for any given load than would otherwise be optimal for whatever octane-rated fuel is being burned. This also would improve the engine's long-term lifespan, at the cost of lower engergy-conversion efficiency (and miles per gallon).

    Most likely, Subaru applied BOTH of these approaches. The inevitable reduction in thermal conversion efficiency that they prduce apparently is greater than the improved, optimized variable valve timing and electronically-controlled throttle can make up.

    Therefore, despite those technological improvements, the XT burns more fuel for any given level of horsepower than the less-stressed X/XS engines. Hence, worse EPA ratings than those vehicles, even though no additional horsepower is required of the XT than of them to complete the tests. This has absolutely nothing to do with the fact that the XT's engine is turbocharged. The same deliberate tradeoffs could be applied to get greater durability from any highly-tuned engine, with the same adverse fuel-consumption results.

    In exchange, because of the resultant lowered stresses, XT owners ought to be rewarded with a significantly longer engine lifespan than will be the case for either the WRX or the STi.

    The flipside is that (if my scenario is accurate) it should actually be easier to dramatically increase the XT's actual power output simply by reprogramming the ECU (to bring it BACK TO the theoretically optimum air/fuel ratios and spark advance) than would be possible with the X/XS, or the WRX, or the STi (each of which is probably already running at or very close to the "ideal" settings.

    These changes will sacrifice the additional longevity Subaru's engineers may have deliberately provided for the XT's more conservative mission in life, but some owners will eagerly accept that tradeoff.

    As for me, I'm a conservative old fart, and so I'll probably have no need to further increase the abundant power my XT already is capable of producing; in my style of driving, I doubt I'll use its full capabilities very often as it is. However, if someone produces a reprogrammed ECU that readjusts the advance and air/fuel ratios closer to the theoretical optimums, strictly to improve the gas mileage without necessarily trying to raise the power, that is a mod I might seriously consider.

    Cheers.

    -jack
  • johnb2251johnb2251 Member Posts: 33
    Ballistic wrote: I realize that there are, sadly, many (too many) who share your perspective, but your cavalier statement bespeaks an attitude that is utterly alien to me. Relatively few people truly have more money than they can ever possibly spend. Other things being equal, lower fuel consumption wastes less money - your money - than greater fuel consumption. Money spent on fuel cannot ever be spent on anything else. Even if that doesn't matter to you, lower fuel consumption usually implies lower atmospheric pollution emissions. If that doesn't matter, lower fuel consumption reduces dependence on foreign oil. If that doesn't matter, lower fuel consumption leaves more domestic oil for other important non-combustion uses. If that doesn't matter, lower fuel consumption delays the need to drill more wells in environmentally sensitive areas. The list goes on. I won't continue with more, because I suspect I'm just wasting my time.

    First, as another pointed out - you were quick to misinterpret my statement. I think you must enjoy rubbing moral indignation in people's faces to jump to that kind of erroneous conclusion. I meant that I didn't care if the XT was as fuel efficient as it could have been, or that it's not as fuel efficient as an XS. The XT is awesome, and I'm getting one regardless taht particular negative. If you had practiced a little netiquette and asked before flaming, you might have saved yourself needless embarrassment.

    Second, can you not recognize the hypocrisy built into your argument? I assume you own a car - it's a pretty safe assumption. If you do, then you're just as guilty as those you want to pillory. If you feel so passionately about oil, then why own a car? Why do you not take public transportation? Why do you not ride a bike or walk? Live too far away? Why don't you move closer? Do you have a 2.5l subaru? Uh oh. You could have picked a much more fuel efficient car. Why didn't you buy a jetta tdi? or a hybrid?

    You're not exactly going out on a limb suggesting that fuel efficiency is important. Most everyone would agree with you. I do. But to hit someone over the head with it is sophomoric, risible nonsense.

    Next time, do everyone a favor and ask a person for clarification before attacking them.
  • xccoachlouxccoachlou Member Posts: 245
    http://www.epa.gov/otaq/cert/dearmfr/gasmel.pdf
    tells us this little tidbit:

    The tests measure the waste substances emitted from consuming the fuel, NOT THE ACTUAL FUEL CONSUMED.

    I think this explains why the Impreza Wagon, and Outback Sport always got about the same mileage as the Forester in the EPA tests.
  • ballisticballistic Member Posts: 1,687
    Ken writes, "I enjoy reading your responses, but your heavy use of quotes makes it difficult to distinguish your answers from those of other posts."

    So what follows
    And this ought to be

    If it works, it works. If not, your instructions were insufficient for my restricted comprehension.

    jb
  • ballisticballistic Member Posts: 1,687
    Ken,

    Obviously I didn't get that right! Close, but no cigar for me.

    jb
  • ballisticballistic Member Posts: 1,687
    Kevin replies, "The simplest explanation is that the EPA's mileage test for the XT was wrong. I have no problem at all accepting this. Only time will tell."

    Juice suggested the same possibility. If so, a re-test might improve the XT's ratings. Won't have any effect on any owner's results, but at least the XT would "look" more competitive with respect to other vehicles' EPA ratings.

    Kevin continues, "It's also likely that folks' mileage experience with the XT will be different: there's more power available, some will use it, some won't. So time might not tell that much."

    No question about that.

    "You are also assuming that the variable valve timing on the XT engine is tuned for efficiency. It might be tuned for performance. There's no reason to believe that Subaru isn't going for the gusto here, regardless of any marketing hoo-hah they distribute."

    Well, actually, I don't agree with that. Continuously variable valve timing ought to be able to accomplish BOTH. At moderate throttle openings/moderate revs/moderate loads, the cam timing can be biased toward the "economy" setting (in terms of intake/exhaust overlap). Crank in more throttle to tell your XT you want more power, and the cam timing shifts to a more agressive overlap. Crank in maximum throttle at high revs, and the variable shifts to the largest available overlap. Voila - regardless of what you ask the engine to do, the intake cams respond with the "best" possible setting for the conditions. No sacrifice (of max power) when you don't need it, while being ready to readjust and provide max power when you do. That's the beauty of continuously variable cam timing, when it's done right. You give up nothing on either end of the scale!

    Question for those better informed than I: Does the XT's (and STi's) ECU control (and flexibly dictate) the timing of the intake cams, or is it purely arrived at via some rigid relationship to (for example) RPM? If the ECU controls the timing, then this is another delicious area for the tuners and reprogrammers to play with.

    FYI: I saw an item on a Japanese Subaru site that (unless I interpreted it incorrectly) indicates that the next-gen Legacy will have AVCS not only on the intake cams, but also on the exhausts on at least one version of its engine. If true, that would be even better than what we're getting.

    jb
  • tidestertidester Member Posts: 10,059
    You can create italics by placing the tags <i> and </i> around the <i>text you want italicized</i>.You can create bold by placing the tags <b> and </b> around the <b>text you want bolded</b>.

    tidester, host
  • ballisticballistic Member Posts: 1,687
    ducttapeguy sez, "I understand your argument, but if that were the case, wouldn't all cars get roughly the same milage? Assuming the coefficient of drag isn't that much different between similar cars?"

    Well, we could make this assumption for discussion, but in fact "similar" cars will indeed have differing frontal areas, coefficients of drag, and so forth. Only when you're comparing two nearly-identical cars (the XS to the XT, for example) will these drag factors actually be the same or nearly so.

    DTG continues, "So say for a midsize SUV, no matter if it had a 4 cyl or V-8, shouldn't it get the same milage since the energy used to propel the car should be the same?"

    The energy necessary to propel the same exact body along the road ought, indeed, to be the same. But - the V-8 engine itself can be expected to have greater internal friction (8 pistons and ring sets reciprocating instead of 4, either more camshafts or one longer one with more bearings, more valve tappets to rub against, and so forth). Thus, even if the power to move a 4-cyl version of the same SUV along the road is exactly the same as for its V-8 version, the latter inevitably burns more fuel just to overcome its greater internal friction. Moreover, the V-8 version almost surely weighs more, so its tires' rolling resistance will be greater. It might even have wider tires, increasing its frontal area (albeit only slightly, but every increase carries a penalty).

    Also - returning to a prior point, it is generally accepted that for Otto-cycle (4-cycle gasoline-burning) engines, the greatest efficiency at converting the fuel's thermal energy into useful mechanical energy is achieved at or near FULL load. At any other load condition, the engine's conversion efficiency falls off. In your example, the underpowered 4-banger, straining to move the SUV at a given rate of acceleration or maintaining a given steady-state speed, is by definition going to be working much closer to its full-load maximum capability than the big, lazy V-8 in its brother. Ergo, all other things being equal, the 4-cyl will (for this reason alone) produce better MPG than the V-8 version loafing alongside it. Parenthetically, this may indeed explain *part* of the XT's inferior EPA ratings compared to the X/XS. The XT is by definition operating at a lower % of its max capability just to develop the same power as the X/XS for any level of acceleration or speed. Thus the XT, at a lower load phase, ought to be slightly less efficient in producing 'x' horsepower than the X/XS. Thanks for helping me see an explanatory factor that I hadn't previously identified!

    Dunno how old you are, but you might remember the infamous "4-6-8"-engined fiasco Cadillac offered in the 1970s as a response to imploding sales following the OPEC embargo. This big V-8 engine, depending on how much power you needed, was capable of supplying fuel to just 4 of its cylinders , or to 6, or to all 8. Its engineers were trying to optimize the engine for exactly the phenomenon I just described. At lower speeds and power demands, they were trying to get 4 of the cylinders to operate at closer to maximum load in order to gain the Otto-cycle higher efficiencies. Only when more power was needed did the extra 2 or 4 cylinders cut in, and by then they also would be operating at the more-efficient higher loads.

    In theory, this should have worked. In practice, the unpowered cylinders were still reciprocating away all the time, and all of the higher frictional losses of the V-8 were still present even when the thing was ostensibly in 4-cyl mode. Moreover, the big V-8 was still as heavy as a regular one, so the penalty of greater tire rolling resistance still plagued the vehicle compared to the same car with a lighter "true" 4-cyl engine. It also turned out to be horrifically unreliable, so the whole experiment was a dismal failure in the marketplace. It is interesting to note that at least one manufacturer is attempting a similar approach today. Maybe they think they've solved some of the Cadillac's shortcomings.

    DTG continues, "Let's compare a 4cyl honda CRV to a BMW X5 4.8L." So assuming it takes 50 hp to travel at 65 mph, Even if the 4 cyl is in a more efficient powerband, is it twice as efficient?"

    If the smallish, lightweight 4-cyl CRV takes 50HP to overcome atmospheric drag, tire rolling resistance, and mechanical friction of all kinds to maintain a given speed, you can be certain the larger, MUCH heavier V-8 X5 will require substantially more. More necessary power to maintain the same speed demands more fuel. Ain't no way around that.

    The EPA regimen accounts for all of these factors (weight, vehicle size/frontal area, actual rolling resistance and mechanical friction <vehicles are tested with wheels turning on dynamometers> EXCEPT coefficients of drag). So far as I know, that's the only real-world factor they disregard.

    jb
  • ballisticballistic Member Posts: 1,687
    john writes, "First, as another pointed out - you were quick to misinterpret my statement."

    ?? Your exact words were "Fuel efficiency doesn't matter to me. I just put my money down on an XT 5-speed. Should be here in July."

    I didn't choose your words. You did. They have a plain and rather unambiguous meaning, regardless of whether or not they conveyed what you intended. You provided zero context to arrive at any other (less obvious) interpretation. When people occasionally misconstrue what I write, I first look at whether I failed to make my meaning clear, because that is my responsibility; it is not theirs to read my mind or fill in the blanks or otherwise extract alternative meanings that aren't consistent with what I wrote. To be more blunt, I take responsibility for my lack of precision or clarity. I don't attempt to angrily and indignantly shift responsibility after the fact onto another who simply took my own plain words at their most obvious face value.

    John continues, "If you had practiced a little netiquette and asked before flaming, you might have saved yourself needless embarrassment."

    I'm not even slightly embarrassed. I was unaware that netiquette has changed so profoundly since I began BBSing twenty years ago. When did it become the duty of the reader to somehow divine a writer's UNstated meaning, or to request clarification where the words he chose are not on their face even faintly unclear? It's easy after a reply to assert that what you said wasn't what you wrote; it's better to write what you claim you meant at the outset. When you don't do that, who is at fault for any misunderstanding?

    John continues, "Second, can you not recognize the hypocrisy built into your argument? I assume you own a car - it's a pretty safe assumption. If you do, then you're just as guilty as those you want to pillory. If you feel so passionately about oil, then why own a car? Why do you not take public transportation? Why do you not ride a bike or walk? Live too far away? Why don't you move closer? Do you have a 2.5l subaru? Uh oh. You could have picked a much more fuel efficient car. Why didn't you buy a jetta tdi? or a hybrid?"

    Let me get this straight: To criticize one who chose to write "Fuel efficiency doesn't matter to me" and avoid your amusing accusation of hypocrisy, I am to avoid owning an auto altogether and walk instead? I gather that according to your standard, drivers of Civics have no standing to protest buyers of Excursions because, after all, Civics sip at least some fuel...

    Continuing: "You're not exactly going out on a limb suggesting that fuel efficiency is important. Most everyone would agree with you. I do."

    It is helpful to now learn that what you wrote earlier did not accurately portray what you think.

    "Next time, do everyone a favor and ask a person for clarification before attacking them."

    I regret that my response offended you. Next time, you might do yourself a favor by not making plain, unambiguous statements in public forums indicating views that you (subsequently) heatedly disavow, but only after the viewpoint you expressed comes under criticism.

    jb
  • ateixeiraateixeira Member Posts: 72,587
    The Subaru Forester XT actually makes power in the 240-260hp range. They only claim 210 to keep insurance rates low.

    You heard it here first. I'd love to see some dyno results once they get broken in and people start on mods. Paul Hansen is already trying to find someone near a vendor to sort of be their guinea pig for mods. Hopefully they'll do a dyno run to establish a baseline.

    You lose, what 20% or so power at the wheels? A 116hp Miata usually gets 95-99 hp at the dyno.

    Doing some math, that means the Forester would make 172hp at the wheels on a dyno (I used the lower number, 95, because AWD has more driveline loss). Maybe even less, in theory.

    I'd love to see what it'll produce in practice. Some say the old STi made over 300hp, never mind the "claimed" 280 or so.

    -juice
  • kenskens Member Posts: 5,869
    Cobb Tuning is supposed to be working on an ECU upgrade for the XT. I'm sure we'll get some interesting technical highlights in the process.

    Ken
  • oregonboyoregonboy Member Posts: 1,650
    If you really-truely care about conserving natural resources, you would limit your transport to walking barefoot. Bikes and shoes are out because their manufacture consumes energy and materials. Maybe shoes made from the carcasses of animals that died of old age would be acceptable. :o)

    Lighten up (please) -james
  • johnb2251johnb2251 Member Posts: 33
    You provided zero context to arrive at any other (less obvious) interpretation

    So your defense is you're too dumb to apply the context of the thread to my post? Wow. Now you really should be embarrassed. Let me spell it out to you as I would a child: the conversation was centered around the surprising lack of fuel efficiency of the XT. I say I don't care about the fuel efficiency, I'm getting one anyway. And then you make a fool of yourself hyperbolizing my statement to mean something sinister about wasting energy resources. If you couldn't manage to figure out the context, then ask! It's that simple. But what you did was self-indulgent adolescent histrionics - and it's plain for everyone to see. That you don't apologize and instead attempt to disingenuously weazel your way out of your words speaks volumes of your character as a person. I am through wasting my time arguing with such a socially inept, ignorant teenager.

    Oh, and if you'd been at least a little intellectually honest, you would have conceded the fact I had a point regarding your hypocritical perspective. Certainly a Civic owner DOES have more moral authority than you!
  • subearusubearu Member Posts: 3,613
    Just got my August issue. They tested an MT.

    Notable points: the final drive ratio is 4.44:1, not 4.11:1 like the X/XS.

    1st: 3.45
    2nd: 2.06
    3rd: 1.45
    4th: 1.09
    5th: 0.78

    Ground clearance: 7.5 inches

    0-60: 5.3 seconds @ 97mph

    top speed: 129mph (5900rpm)

    8-)

    Well, we at least now know some reasoning behind the lower mpg...

    -Brian
  • kullenbergkullenberg Member Posts: 283
    We used to have a saying in the aviation engineering community: "arguing with an engineer is like mud wrestling with a pig - you soon find out that he enjoys it!" That seems to be going on here. Keep up your informative and well thought out posts, Jack.
    Cheers
    Pat
  • subearusubearu Member Posts: 3,613
    (includes quotes from the August 2003 C&D)

    They liked the 5 speed, and mention "at no time during this period (600 mile one day drive) did anyone not smile a little when driving the XT"

    "The shifter was as sweet as a peach, the clutch nice and light, and the engine truly heroic. With this kind of power and weight, the little XT ends up as the only real hot rod in the entire small-SUV spectrum""

    -Brian
  • corkfishcorkfish Member Posts: 537
    Wait a minute. 0 to 60 in 5.3 seconds? Are you sure that's not 6.3?
  • subearusubearu Member Posts: 3,613
    I did a double take as well. Page 111 clearly states 5.3 seconds. It could be a typo, but the chart on pg. 113 shows 0-70 @ 6.9 seconds, 0-60 @ 5.3 seconds.

    Standing 1/4 mile: 13.8 seconds @ 97mph
    Street start 5-60mph: 6.3 seconds

    C&D doesn't have the article online yet.

    -Brian
  • rshollandrsholland Member Posts: 19,788
    That is indeed quick!

    Bob
  • ateixeiraateixeira Member Posts: 72,587
    GREAT SCOTT! 5.3? You kiddin' me? That beats several WRXs they have tested! :-)

    13.8 quarter mile also beats the WRX.

    Told ya'll it was fast! I don't think people understood just how fast it was!

    -juice
  • corkfishcorkfish Member Posts: 537
    That's really astonishing if it's true. Quarter mile in the 13's! What a sleeper. I wonder if the horsepower figures are understated. Dodge did that with the Neon SRT. Some dynos are showing it has well over the advertised 215 horsepower. Reminds of of the old GMC Typhoon. If this thing really offers that kind of performance I may have to buy two of them! I've been waiting for years for a socially acceptable muscle car. Sign me up.
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