What about fuel types & gas mileage?



  • asmith10asmith10 Member Posts: 2
  • dardson1dardson1 Member Posts: 696
    Perhaps not although from time to time my Tahoe gas bill is padded in a similar way. It's just an interesting observation I've made over the last two years.
       I've not got a clue what kind of milage her Lexus gets. The sticker suggested 19 city. If she drives 800 miles in a month and assuming she gets 19mpg she's gotta buy 42 gallons of premium fuel. If I drive the same 800 miles I have to buy 53 gallons (averaging 15mpg) of regular fuel. If you do the math and considering the 20 cent diffence in premium vs regular it cost me less than 9 bucks a month (more) to drive the Tahoe. Add a few hotdogs, a couple of soft drinks, and you're there!
  • markludmarklud Member Posts: 41
    I live in N.E. Pa. Since the autumn I've noticed a larger than usual drop in fuel milage in both my vehicles. My 4cyl went from 27 to 21mpg and 6cyl from 20 to 15mpg. I know cold weather will result in richer fuel mixtures, but this year is the biggest drop I've ever seen. The fact that both vehicles experienced this, makes me think it is the gas. I've read about oxygenated gas causing poor milage, but don't know how to find out if it's used in this area,or if it is, is this the first year for it. I've tried 2 or 3 different gas stations and have similar results in mpg. Any suggestions or opinions?
  • swschradswschrad Member Posts: 2,171
    the pumps are also required to post a sticker if ethanol is the oxygenator used in MN, IA, NE, ND, and lots of those wonderful corn/farm states. if the oxygenator is methyl tertiary butyl ether (MTBE) there is a big move on to ban it in year X, and identify it in months, and sooner or later that bill will pass nationally. at present, MTBE fuel is labelled in a few places.

    there may be states that require "oxygenated" type stickers on the pumps.

    you have hit the surest way to tell, a drop of between 10 and 20 percent in the gas mileage all of a sudden, and near the onset of winter.

    your state commerce department should have the information, or their antipollution arm, and may have a website. a quick Googling of "pennsylvania department commerce" yielded something on the third page that led to a promising link that found a home page that allowed a search for "gasoline" which led to this


    which provides a good place to start. in a minute of poking about here, I found backlinks to the US DOT for low-sulfur gas and one dead link.

    Google is your friend for starting wild-goose chases like this, and you can find lots of interesting bar-bet stuff along the way.
  • markludmarklud Member Posts: 41
    At the risk of sounding like a "conspiracy theory" follower,it really seems like a ploy to make the general public pay more for gas even though the oil companies so graciously lowered the price of gas from the ludicrous $1.75/gal! Now I get crappy gas mileage even with my 4cy, thank you!P.S. I used to see pumps that say their gas containes ethanol, but no longer see any such designation. So I assumed they didn't have it.
  • swschradswschrad Member Posts: 2,171
    and we have marked your answer down In The Book down at conspiracy headquarters LOL :-D
  • chinkapin02chinkapin02 Member Posts: 4
    I suggest using the octane called for by the car mfg.
    HOWEVER how many of you pull into your local gas station and fill up when there is a tanker unloading gas into the storage tanks? Not many people think of this and most don't even notice.
    I NEVER gas up while gas is being pumped from the tanker into the underground storage. Do you know how much water is in that underground tank? Underground storage tanks are allowed to have so much water in them and when fuel is being pumped into the tank that water does get mixed into the gas then into your fuel tank.
  • q45manq45man Member Posts: 416
    The problem with Ethanol is it consumes so much oil and oil products [diesel, fertilizer]to grow the corn, cut the corn , transport the corn, and convert it to ethanol........massive boondogle which doesn't decrease foreign oil consumption one bit, if anything it increases the imports to support the farming.

    Ethanol creates more hazardous pollution than conventional gasoline........since engine ecu are calibrated for non oxygenated fuels.
  • gregoryc1gregoryc1 Member Posts: 766
    My wife and I own two Honda vehicles. Both are 4 cyliner automatics. (2003 Honda Accord and a 2004 Honda Civic). The owners manual states that you can use 86 or higher octane fuel. We use premium fuel in both vehicles, with an upper cylinder lubricant. We also change the oil and filter every 3,000 miles. Our engines run very smooth, and we have great acceleration. Using premium fuel is just a personal decision. We want to prevent the possibility of a spark knock under load, especially under "hard acceleration" when getting into traffic on the highway.
  • badgerfanbadgerfan Member Posts: 1,565
    I guess your preference is to waste money. The fact is neither of your four cylinder hondas require premium fuel and you are gaining absolutely no benefit at all.

    If you do ever notice engine knock in those two cars, it is because you have some other malfunction.
  • gregoryc1gregoryc1 Member Posts: 766
    "I guess your preference is to waste money"! ----That is a "judgement call" on your part!----- In the Honda manual it states that the owner can use 86 or higher octane fuel in the engine.----- Not all fuels sold at stations are the same. I don't drink, smoke or gamble, so my only problem is burning premium fuel. That is not bad when you consider the results to the other things. (Drinking = health / liver issues, Smoking = Lung Cancer amd Gambling = loss of savings and life style). I will take purchasing Premium Fuel as a personal issue any day! In addition to purchasing that high priced premium fuel, I also change the oil and filter every 3,000 miles, because I love a clean crankcase, and clean oil in the engine. The oil is so clean on the dip stick of our two Honda engines, that I can harding see the old level, and the 2003 Accord has 20,000 miles on the clock. Yes, I do spend money on "preventive maintenance", and I love the total experience. Just yesterday, I took my wife's 2004 Honda Civic for a 3,000 mile oil and filter change at the dealer. I had a great experience. I arrived at the dealership with three cups of flavored coffee,(one for my wife, myself and the service writer), and in addition, I gave the mechanic $5.00 as a tip for the service rendered. Yes, I love to spend money on my things and on people that I like. Life is just too short to be cheap! -----And, I never knew anyone that was able to take their money with them when they died.----- Don't try to bring the war in under budget! ---- Life is more than a "balance sheet"!
  • badgerfanbadgerfan Member Posts: 1,565
    Well, go ahead and buy premium fuel and tip the mechanic and do whatever else you want with your money, fact is you are still wasting your money when spending it on premium fuel. And that is not a judgement call, that is just following what all manufacturers will tell you and also is based on well known facts-an engine that is not a high performance engine with high compression ratios cannot derive any benefit from premium fuel. If it doesn't knock under heavy load, the engine is not being harmed. You will not derive any performance improvement using premium fuel in a car that is not designed to take advantage of premium fuel. You can argue about premium fuels having better additive packages that may burn cleaner, but that also is a separate issue from octane rating.

    I won't argue with your changing oil every 3k miles as I do it at that interval also, but I change it myself thus spending less than $9 per change for filter and oil. It is much more convenient for me to do it myself-I do it when I want and it is an easy job. Waste oil is properly disposed of at our community recycling facility, so I am not polluting the environment with the waste oil either.
  • rae52rae52 Member Posts: 103
    gregoryc1, have you ever tried using midgrade (89 octane) in your two cars?
  • concrete1717concrete1717 Member Posts: 29
    RE: 24 MAR 2004 press release from Bluewater Network:

    The EPA currently bases their fuel mileage estimates upon emission test data from the vehicle industry, then reports the results at 10% to 22% below the test data. Bluewater Network claims that estimate is still averaging 4-5 mpg above actual on-the-road performance. The EPA is responding to a petition from the environmental organization.
  • q45manq45man Member Posts: 416
    The major problem is the average road speed has increased above that used in 1985 calculations.

    If they just pointed out that the highway tests are based on a rural highway with an average speed of 55 mph and nothing in excess of 60.5 mph it would be clear that going 70mph decreases mpg by 22% DUH.
  • badgerfanbadgerfan Member Posts: 1,565
    Yes, but how do you explain that I can easily exceed the EPA highway mileage by 2-4 mpg on my 2000 Taurus Duratech, and this at speeds of about 70-75 mph?

    I can understand city ratings being off either way because of the wide range of city driving different people encounter, but highway mileage should be closer.

    The hybrids, on the other hand, do not seem to be able to even nearly approach the EPA numbers, though their actual mileage may still beat the conventional cars.

    I think the EPA tests methods are much too artificial, but not consistently low or high.
  • dirt80dirt80 Member Posts: 1
    I have a 2002 Jetta TDI with an automatic transmission. The mileage is rated at 45 mpg highway. I have had the vehicle for approx 6 months now. I drive 50 miles one-way to work each day at approx 75 miles per hour. I average only 38-40 mpg. No more, no less. I was expecting mileage closer to 45 mpg. Anyone have any ideas on why my mileage is so low?
  • corvettecorvette United StatesMember Posts: 8,462
    Could be: Clogged air filter, clogged EGR, or everything operating normally. Try switching brands of diesel and/or driving slower. Are your tires inflated properly? Are they still using "winterized" diesel in your location? Just some random thoughts...
  • snarkssnarks Member Posts: 207
    Try drivng at 65 mph and you'll find mileage goes up. EPA mileage I believe is rated at 55 mph with all accersories off.
  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaMember Posts: 64,482
    Also EPA doesn't use headwinds!
  • bowke28bowke28 Member Posts: 2,185
    i have a 2003 Focus SE sedan, 7000 miles. on my way home last night, the gas guage read empty, although i had just filled up that morning. as i looked at it wondering what happened, the engine light came on.

    i took it in to service last night, and they called me this afternoon saying its done.

    turns out that superamerica fuel has been ruining fuel pumps in fords, chryslers, chevys, hondas, toyotas, etc...pretty much everything. there is a news article about how AAA has has triple the fuel calls over the last week, with people reading 1/2 tank but running out.

    anyway, they replaced the fuel pump (in under 24 hours, by the way), and all seems fine. they said it might happen again, since i still have the gas in it, but that superamerica will be reimbursing FoMoCo when all is said and done, so they dont mind doing it again.

    please let me know if you have issues like this, so we can organize our efforts.

    i have a feeling that superamerica is "watering down" their gas...kind of like ballparks do with beer.
  • swschradswschrad Member Posts: 2,171
    oh, excuse me, it's just that their refinery in st. paul has conked out and will be u/s for a couple of weeks or so. so SAs here are buying whatever they can instead of using their own product from the marathon/ashland refinery, those companies having been bought by speedway several years ago. SA is a speedway company, was an ashland division.

    for your issue, sounds like they found an Additive From Hell that is dissolving the fuel pumps. haven't heard of anything like that in the minnesota area, but gas formulations are increasingly regional these days, and "AFH" may be moderately unique to kentucky.
  • bowke28bowke28 Member Posts: 2,185
    that in metro louisville, there is an additive that reduces emissions, but everyone is mandated to use it for the last 15 years or so. AFAIK, superamerica is going strong...they are everywhere around here, and always busy.
  • swschradswschrad Member Posts: 2,171
    one of the crackers is down, so they're at half production. SA has made it up with other sources. snooze papers got partial information just in time to make press on friday. in my area, SA is temporarily the cheapest gas, where they are usually 3 to 8 cents above the guys using the pipline, but that varies according to phase of the moon and groundhog heart rates, etc.

    around here, they are also a major pumper. if they sold rotwater on a regular basis, there would be hell to pay and they'd be on the news every hour on the hour. they'd have to post pictures of wacko bin looney to boost their popularity ;) so I don't think there is a corporate-wide issue.

    I think the issue in your area of louisville probably revolves on whether they recently did any service work on the pumps, whether different stations get bulk fuel from different sources, where did the additive package come from, etc. it's not impossible that somebody screwed up and used methanol as an octane booster instead of ethanol, for instance, and methanol alcohol has a history of causing corrosion even on old-style mechanical pump fuel systems. one or two wrong tank cars full of alcohol at the blending house would be all it takes to cause a rash of issues. if so, this would also go away quickly, like in a few weeks.

    in that case, it would more likely be a problem of Killco Chemicals or whatever outfit supplied the alcohol, but SA takes the blame because they market the gas and get the public notice. it will doubtless be sorted out as a version of Everybody vs. Everybody Else in one of your fine civil courts.
  • bowke28bowke28 Member Posts: 2,185
    i have driven over 100 miles with the new pump and the same gas, and nothing weird happening.
  • swschradswschrad Member Posts: 2,171
    the owners manuals of the last few cars I have had indicate although the carmakers hate the thought of methanol with a passion, they can generally burn up to 5% volume of the slop in a tankful.

    almost all cars can run 10% ethanol with no issues whatsoever, and those that don't fall into that category can burn E85, which is 85% ethanol by volume, and run just as well as on non-oxygenated gas. E85 cars will have a "green leaf" symbol on them, and generally recent fords with smaller engines such as rangers and tauruses with the base engine will have a "green leaf" on their backside.

    so if you had 6 gallons of methanol-mix fuel at, say, 10%, and you put in 6 to 7 gallons of any non-methanol fuel, you're legal again. it isn't perfect, but not urgent.

    again, I suspect your local issue was a one-time problem. if it recurs, somebody is being seriously sloppy or ignorant in the fuel business, and they need to be spanked and sent home. your local channel 13 Witless News Consumer Line Action Reporter is a good place to start
  • bowke28bowke28 Member Posts: 2,185
    with the news station, and they called me back. they asked me to call again if the problem persists. (obviously, since im not sitting on the side of the road with a dead baby in my arms and a heroin needle sticking out of my arm).

  • mitzijmitzij Member Posts: 613
    No Bleed, No Lead...
  • swschradswschrad Member Posts: 2,171
    and if it takes more than a day or so of folks scuttling around to assemble a case that, say, Spilco puts paint remover in its gas and hates you to boot... then is it worth the trouble? after all, we have sauna places that May Be Houses Of Sin, and there is the matter of the breakthrough investigation of Why There Is All That Air In Potato Chip Bags, And What It Costs You. got to get those priorities right.

    seriously, they are filtering out one-shots that are being addressed by the free warranty repairs. if it persists, then there may be an issue worth chasing for the costs the station has to bear.
  • dcg02dcg02 Member Posts: 1
    good day to all...i have read that using the a/c during summer actually saves on gas only on some vehicles, is this true? if so on which cars? for newer models, is it better to always use the a/c? i appreciate your input.
  • swschradswschrad Member Posts: 2,171
    in most cars now, it's in the 0.3 to 0.4 range, and you should find that using the air beats windows-down. HINT: I would suspect that if you can get the dreaded WHUMP-WHUMP-WHUMP!! with two windows down in any combination, any amount of up or down, in your vehicle, you need to use your air, instead, to save gas. that WHUMP!!-ing is turbulent air spoiled by the change in wind resistance and causing standing waves that extend over the air stream into your car.
  • deadeyedeadeye Member Posts: 2
    Hello I seem to have a fuel problem.I used to get 16 mpg then I tow a boat from FL to NJ in Sept 2003 my mpg dropped to 11 mpg So I put K&N air filter change the fuel filter every oil change reset the computer to allow for the air but I still can't get above 12.5 mpg.HELP it's driving me crazy .
  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaMember Posts: 64,482
    do you check tire pressure and alignment?

    Actually 12.5 is not out of the ordinary for this truck, especially when towing.
  • tomsr1tomsr1 Member Posts: 130
    Could it be that to meet smog control standards you need to run 91 octane and if you don't care then 87 or 89 works fine with no damage to the engine.It is puzzling why two engines with 10:1 compression need different fuels.I don't know the answer,maybe someone smarter than me does.I have ran 91 octane in my 01 Acura TL for 49000 miles and today tried a tank of 89 and see no difference.When I bought it a salesman said they put 89 in them.
  • shiposhipo Member Posts: 9,148
    Not all combustion chambers are created equal. Some combustion chambers breathe better, some have better control of the flame front, some run cooler, some allow for an early spark, some yield more power at the expense of efficiency or cleanliness, others are just the reverse, unfortunately creating a chamber that can do it all is virtually impossible. Every manufacturer is faced with what is the best compromise design for their target market, and as such, some cars with a 10:1 can run on regular or mid-grade while other engines with a similar or even lower compression ratio require and/or can take advantage of premium.

    Best Regards,
  • roper2roper2 Member Posts: 61
    I was thinking about cleaning the throttle body and was wandering what is the best product to use.What about the sensors donot want to damage them. I have a 4.7 Thanks
  • alcanalcan Member Posts: 2,550
    Any brand of air intake cleaner with "sensor safe" on the label. Don't use carb cleaner.
  • buckshotbuckshot Member Posts: 2
    I'm looking for inexpensive ways to improve the economy of my 1990 Ranger XLT, its got the 2.9L V6 with a 5 speed standard transmision.
  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaMember Posts: 64,482
    Really not much you can do inexpensively that would really pay off. Some people claim synthetic oil or special air filtersoffer increases but whenever these things are scientifically measured it doesn't seem even worth the cost of the item itself to do this. The results are pretty meager, maybe like 3% gain in fuel mileage kinda sorta maybe.

    Best thing in my book is checking tire pressures, doing a 4-wheel alignment and reviewing your driving habits.

    Also, your climate will vary your fuel mileage considerably. 60-70 degrees is supposed to be ideal, and the mileage falls off on either end of that proportionally to the degree higher or lower than that optimum.
  • steverstever Guest Posts: 52,457
    Would anyone care to comment on this thread:

    habitat1 "Lexus GX 470" Oct 26, 2004 7:31am

    "I trust my more technically qualified associates who can describe how a high compression engine operates and that constantly overriding timing adjustments will reduce fuel efficiency and performance. And MAY result in other consequences."

    I'm thinking that the timing is constantly being adjusted regardless of the octane in the tank.


    Steve, Host
  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaMember Posts: 64,482
    I'm not sure I understand the question.
  • steverstever Guest Posts: 52,457
    This is the crux paragraph, especially the last sentence:

    "Just about every modern engine has knock sensors that will adjust the engine timing to prevent knocking if you use lower octane fuel. But they do so by a method which, by it's very nature, will affect optimal performance and gas mileage. Very slightly in some cases, more noticable in others. And over long periods of time, i.e. 3-5+ years and 60-100k+ miles, the constant timing adjustment can have other adverse consequences on the engine."

    habitat1 "Lexus GX 470" Oct 24, 2004 8:01am

    Steve, Host
  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaMember Posts: 64,482
    I really don't get the logic of this argument. If the system prevents knocking then how can there be any adverse consequences on the engine. It's the detonation that's an engine killer. Timing that is a bit retarded or advanced for an instant won't hurt anything.

    Besides, this is a theory in search of proof, which just isn't there.
  • corvettecorvette United StatesMember Posts: 8,462
    I think the argument is, that even with the computer controls, if you run an engine designed for premium on regular, some knock occurs before timing is retarded. I am not sure, nor am I qualified to comment on, whether some occasional knock (enough to trip the knock sensor and retard the timing) will adversely affect the long-term reliability of the engine. Any thoughts?
  • imidazol97imidazol97 Crossroads of America I70 & I75 Member Posts: 25,710
    A mechanic says that the optimum power and efficiency occurs with a slight knock under load. While it's not pleasant to the ear in cars without insulation, the knock is inaudible to the passengers in a 'quieted' car.

    Perhaps this tenet is that if using premium does damage to cars tuned and built for 87 because of the slower burning leaving more deposits, then the inverse syllogism is true; using regular in cars tuned for premium must not burn correctly leaving something behind.

    I realize that the engines in some discussions about this ( Lexus?) say use 87 but premium is suggested for optimum performance. There might be a difference between an engine that says premium only and one that says "I'm versatile."

    2014 Malibu 2LT, 2015 Cruze 2LT,

  • corvettecorvette United StatesMember Posts: 8,462
    ...the inverse syllogism is true; using regular in cars tuned for premium must not burn correctly leaving something behind.


    I have always heard that using premium in cars designed for regular can lead to carbon deposits.
  • steverstever Guest Posts: 52,457
    And does the timing then get advanced to the detriment of ... well, something? :-)

    Steve, Host
  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaMember Posts: 64,482
    A little knock doesn't do any harm, that's true. I mean, look at old Volvos...they would knock on 105 octane if you could buy it and they certainly didn't blow up very often.
  • imidazol97imidazol97 Crossroads of America I70 & I75 Member Posts: 25,710
    I would assume the timing can only vary with certain values for any engine speed. So using premium which resists pinging would not cause excessive advance to the spark.

    I was told by a mechanic that some early GMs would die if you used good premium in them. When the car came to idle, it would advance the spark until knock was sensed and then adjust the spark based on that test. No knock, and it advanced more and the car died.

    I have used premium in my 3800 for more than one tank rarely in the past. Never happened to me. Then I learned that the deposits left behind were more of a problem than the better detergents which really are in the premium anyhow. (Does anyone have proof that there are better inject maintenance productws in premium?)

    2014 Malibu 2LT, 2015 Cruze 2LT,

  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaMember Posts: 64,482
    It comes back to the same old rule of thumb. Use the gas grade for which your engine was designed. Putting 93 octane in an engine designed, mapped and computerized to run on 87 is therefore a complete waste of money. There's no more "power" in high test or more "good stuff", it's just more even-burning, which a higher compression engine needs.
Sign In or Register to comment.