Hybrid Tips Optimizing mileage

135678

Comments

  • john1701ajohn1701a Member Posts: 1,897
    > So if it happens to go down

    After over 78,000 miles of driving Prius, I have yet to encounter that situation. In fact, I haven't even come close to it.

    In other words, is it quite a bit more rare and far more predictable than has been implied.

    JOHN
  • abennettabennett Member Posts: 5
    I drive both city and highway, have about 4000 miles on the car and the mileage is declining steadily. It drives fine, but has anyone else had this experience?
  • stevedebistevedebi LAMember Posts: 4,098
    Just a suggestion, but you might want to post this in the Toyota Prius: Problems and Solutions forum. You might get more results...
  • john1701ajohn1701a Member Posts: 1,897
    Tire-Pressure decreases naturally. The tires will become steadily softer and softer. That will definitely cause lower MPG.

    Break-In Oil becomes increasingly thicker and thicker. By 4,000 miles, you are pushing it... not damaging anything, but hurting MPG.

    If you live in an area with a lot of sand & dust, you may actually have an impaired engine air-filter. That will reduce MPG too.

    You may have picked up a counter-productive habit, misinterpretting what the Multi-Display is telling you. Some owners unknowingly fight the system when they see the green MPG bar drop really low during acceleration and climbing hills.

    JOHN
  • stevedebistevedebi LAMember Posts: 4,098
    "Break-In Oil becomes increasingly thicker and thicker. By 4,000 miles, you are pushing it... not damaging anything, but hurting MPG."

    Interesting you should mention this for Prius. The Honda 2.4L comes with break in oil that the factory recommends keeping in as long as possible (up to the scheduled 10K maintenance). I kept mine in for 7K, which is 2K past the normal 5K "severe" interval for the 2.4L...
  • solar_dadsolar_dad Member Posts: 22
    A general question to those with the HCH - do you get better mileage by accelerating briskly, then backing off, or creeping up on your desired speed? A discussion group on a manual Insight seemed to suggest punching it to maximize the electric assist. Does this apply to the CVT also?

    Thanks,
    Mike
  • mistermemisterme Member Posts: 407
    I've done a series of tests a few months ago that shows gradual MPH increase will yield better MPG with a CVT HCH. A very gradual speed increase can provide almost double the MPG of a full throttle start.

    Your best MPG is not found while the battery is recharging.
  • PF_FlyerPF_Flyer Pennsylvania Furnace, PAMember Posts: 9,400
    Be sure to check out our Town Hall chat lineup for Tuesdays... everyone is welcome and ALL things automotive (and some not-so-automotive topics) are fair game! Stop in tonight and get to know some of your fellow Town Hall residents better. We may even play a little automotive trivia!

    Getting things started, from 6-7pm PT/9-10pm ET, If your passion is Mazda or you just like to go ZOOM ZOOM, the place to be is the Mazda Mania chat.

    Mazda Mania Chat Room

    Imediately following from 7-8pm PT/10-11pm ET, talk the latest in new automotive technology during the Hybrid Vehicles Chat

    Hybrid Vehicles Chat Room

    The Town Hall chats are a great place to take these message board topics LIVE. Hope to see you there this week!

    PF Flyer
    Host
    Pickups & News & Views Message Boards
  • quasar4quasar4 Member Posts: 110
    --Here's a tip that might save a little bit of juice...

     

    In the winter time, instead of running the car at idle waiting for the engine to warm up, put the car in gear and drive very gently for a few minutes (provided of course that your windows aren't caked in ice...use common sense). The car will actually warm up faster and, from what I read, the negative effects of uncombusted fuel will be lessened. Improved fuel economy, better performance, less pollution.......what's not to like?
  • mistermemisterme Member Posts: 407
    Nice informative post. Thanks.

     

    More on the extreme side, may I add to try and not use cabin heat until the engine is completely warmed up. With burning so little fuel, you can have potentially better results as you are not heating both a cold engine and cabin at the same time.
  • quasar4quasar4 Member Posts: 110
    --You must be a mind reader, 'cuz that was gonna be my next post!

     

    --I usually don't turn on the heat with a cold engine if I'm stuck at a stoplight. The engine would just keep running to heat the cabin. I turn it on as soon as the light turns green and my engine has to be on anyway to accelerate the car.
  • electrictroyelectrictroy Member Posts: 564
    Drive slow (55).

     

    Avoid braking (wastes energy).

     

    Watch your Instant MPG Bar & keep it at 80 or higher.

     

    troy
  • robertsmxrobertsmx Member Posts: 5,525
    Avoiding braking isn't advisable, but avoiding abrupt braking is. In other words, drive smoothly.
  • blueiedgodblueiedgod Member Posts: 2,798
    Drive slow (55).

      

    Avoid braking (wastes energy).

      

    Watch your Instant MPG Bar & keep it at 80 or higher.

      

    troy


     

    Avoid driving personal vehicle, take public transportation, you save money, evironment and natural resources.

     

    :-)

     

    Sorry, couldn't stop my self.
  • Kirstie_HKirstie_H EdmundsAdministrator Posts: 11,132
    But that doesn't exactly up the MPG, does it? While one may pay less for gas and use less gas overall, it doesn't really count as "optimizing mileage." Since this is an automotive forum, we run on the premise that members who visit this topic either own a hybrid or are interested in driving one, not avoiding doing so.

     

    kirstie_h

    Roving Host

    Host, Future Vehicles & Smart Shopper discussions

    MODERATOR

    Need help navigating? [email protected] - or send a private message by clicking on my name.

    Share your vehicle reviews

  • electrictroyelectrictroy Member Posts: 564
    kirsti_h should delete that last post, because it's off-topic.

     

    .

     

    "Avoiding braking isn't advisable, but avoiding abrupt braking is."

     

    .

    I've found that if I look ahead & plan, I only need to brake 2 or 3 times during my daily 70-mile commute.

     

    So to repeat: Avoid braking...it wastes energy.

     

    troy
  • quasar4quasar4 Member Posts: 110
    --Let's cut blueiedgod some slack. He did use a smiley face afterall. As for it not being on topic, kirstie_h, it's more on topic than 90% of the posts in this forum (see the first 14 posts or simply read posts #15 and #96 for example). Besides, if you want to get technical, the hybrid tip topic "Optimizing Mileage" doesn't necessarily mean the same as "Optimizing Fuel Economy," or "Optimizing MPG," but I digress... ;-) <------see smiley face.

     

    --Back on topic, avoiding braking is advisable, as long as safety is not jeopardized...but we all knew that already...right?
  • quasar4quasar4 Member Posts: 110
    --Your post does raise a question or two concerning heater operation. Cranking up the heat in my old '90 Civic would result in a lot of seemingly cold air being blown out while waiting for engine warm-up. The Prius, however, appears to automatically delay fan operation until the engine is warm enough to provide some real heat. A welcome touch. With that said, it would appear to be okay from the standpoint of fuel economy to turn on the heat even if the engine is not warmed up, as long as your engine is under a load where it has to be running to spin the wheels anyway.

     

    --Just curious: Does a smaller HP engine warm up faster than a larger, more massive, HP engine with all other conditions being equal?

     

    --Would the mere act of using the heater reduce the efficiency of the engine in the winter by pulling waste heat away from it (e.g., would there be any difference in fuel consumption driving up a long hill with the heater on --discounting the energy required to operate the fan-- as compared to driving up the same hill with the heater off?)? Or does the amount of heat vented to the cabin have such a negligible effect on engine efficiency as to be a non-issue?

     

    --If the cold weather has a negative effect on battery efficiency, then would it make sense to keep the cabin as warm as possible in the winter so as to warm up the battery pack in the rear of the car?

     

    --Is the forced vent heat supplied solely from engine combustion? Or is there a supplementary electric heating element?
  • mistermemisterme Member Posts: 407
    Honestly, I haven't researched heater operation in the winter but it just makes sense to me.

     

    I understand the Prius has an electric heater, not tied to engine coolant so I suppose it wouldn't matter in that case.

    HCH has a conventional heater core.

     

    ICE is more efficient when warmed up. Your engine thermostat keeps the coolant from flowing into the radiator to keep the growing heat from dissipating into the air, holding the heat inside the engine block until it reaches operating temperature.

    The heat has a 2nd designed path to escape the block while it is warming up, the heater core, which acts as a mini radiator.

    The only thermostat for this mini radiator is the cabin temperature control.

     

    I know in the past vehicles I've been trapped in a slow moving traffic jam during the summer, only to find the temp gauge climbing higher & higher.

    I've been able to vent the cabin, set the cabin temp to hot, blower fan on high to stabilize my rising engine temp. Alot of heat can be dissipated from the engine out of the heater core.

     

    It makes sense to me that the engine will take longer in freezing temps to heat if I turn on that "2nd radiator" before the engine has a chance to fully warm up.

     

    It's true that batteries are less efficient when cold, but in the case of HCH, how long does it take for cabin heat to actually reach the batteries? First the engine would have to heat both itself & the cabin, then the back seat cushion, then the electronic plastic & metal casings, then the batteries themselves.

    There is a vent on the top rear deck for the electronics. I wonder does this direct cabin heat to the batteries, a vent for the electronics or both?

     

    The batteries also heat by themselves as they are being used.

     

    I think the 1st priority would be getting that ICE warmed up.

    Does it make any sense?
  • kernickkernick Member Posts: 4,072
    Tires like the Bridgestone Blizzak have soft rubber compounds, to provide better control and braking on ice by creating micro-suction areas within the rubber. This decreases mpg obviously, and if you have special low-rolling-resistance tires, you have forfeited those.

     

    Also high tire pressures which give you better mpg, also decrease the contact patch between tire and road/snow/ice.

     

    So what do you guys suggest or do for winter driving? What's more important safety - as in better control and braking, or mpg? Since many of you are talking about how to save the tiniest bit of gas by not warming up the vehicle and running the heater til warm, I'd guess you're not advocating snow tires?

     

    Also avoiding braking as long as possible based on your determination of what is safe, is not a good idea. As you may 1 second be on pavement and the next on black ice, and never have known the difference, you may be in for a bad surprise when you estimate where you're going to stop. You may find yourself hitting a pedestrian in a crosswalk, a car stopped at a light or Stop sign, or simply slide right thru the intersection. For safety's sake you start braking early, testing the road conditions, and giving yourself a good margin of error.

     

    Sorry if you don't like this post, but as on many of these forums I point out that all decisions have positives AND negatives. Don't just focus on the positives. To make decisions based on MPG-alone, is not in your best interest or anyone else's.
  • tempusvntempusvn Member Posts: 119
    "Also high tire pressures which give you better mpg, also decrease the contact patch between tire and road/snow/ice."

     

    No, No, No

     

    Higher pressure is better for handling on dry pavement, handling on wet pavement, and on snow as well. That's why many people put on narrower tires in the winter.
  • kernickkernick Member Posts: 4,072
    Saying "No" multiple times does not make it so.

    If you have a link that says less contact patch is better for a street/passenger car, then please provide it. Here is my professional link - I think Michelin knows a little bit more than we do - stating that their Michelin Arctic Alpin has a "high contact tread-design and expanded contact patch". This is Note C under the tire picture.

     

    http://www.michelinman.com/assets/pdfs/doc_arcticalpin.pdf

      

    By saying don't use high pressure, I'm not advocating low pressure; you should use recommended pressure in this tire.

     

    By the way do you think it's worth people who may experience snow to use snow-tires to increase safety?
  • quasar4quasar4 Member Posts: 110
    --Thanks for the input, misterme. What you say does appear to have a ring of truth to it especially knowing that the heat can escape from two paths (I had assumed that the heat would only be permitted into the cabin if the engine was warmed-up, but from what you're saying, it is channeled from the core into the cabin as soon as you turn on the heat). Although it does appear to me that very little air flows through the vents until there is enough heat so that cold air is not blown out. Something must be controlling that action. I guess a lot depends on how much excess heat the smaller Prius engine produces and retains once warmed-up, and how much heat you're siphoning off into the cabin. I would imagine there is some operating temperature where engine efficiency is at a peak, but to either side of that peak the effiency would drop off (unless of course the operating curve for most steady-state conditions is actually a plateau).
  • mistermemisterme Member Posts: 407
    I can't give any input for Prius, but when the temps at 3:00AM here in Atlanta are the coldest (teens) I've noticed my HCH isn't fully warmed up until I've crossed 20 miles.

     

    The first 2-3 miles are worse, and the temp gauge shows normal at about 3 miles.

     

    I notice improvements after I've driven 3, 7, 10 & 20 miles out.
  • kernickkernick Member Posts: 4,072
    Hmmm. Someone in NH where I live had better have a heated garage in that case. It wouldn't be much fun those mornings when the temp. is below 0F like last night! But then what kind of energy savings would you have?

     

    If hybrids continue like the Prius offering all the creature comforts such as AC, stereos and power options, I would include "an effective heater" as equally important. And the only way to produce heat is to burn fuel. Of course you want to start drivng right away too, so the best thing would be to begin driving after 30 sec. of getting the oil pumped around the engine. But you need to burn some gas and get that car up to temperature.

     
  • tempusvntempusvn Member Posts: 119
    Sure, We'll match Michelin with Goodyear

     

    Here are published numbers for Goodyear Tires with a Max Sidewall Inflation Pressure of 35 PSI for vehicles that 'recommend' a pressure below the maximum.

     

    #############################

     

    Dry Macadam Surface

    (Stopping Distance in Feet)

     

    2001 Dodge Grand Caravan Sport__20 psi__28 psi__35 psi

    Full Depth Tread with ABS_________75.5____76.2____75.8

    1/2 Depth Tread with ABS__________69.9____68.1____66.3

    Full Depth Tread without ABS______98.3____95.9____91.6

     

    1997 Ford Ranger

    Full Depth Tread with ABS_________80.8____78.2____77.6

    1/2 Depth Tread with ABS__________79.0____74.8____71.4

    Full Depth Tread without ABS______97.8____96.5____94.1

     

    #############################

     

    0.02 Inch Wet Macadam Surface

    (Stopping Distance in Feet)

     

    2001 Dodge Grand Caravan Sport__20 psi__28 psi__35 psi

    Full Depth Tread with ABS_________79.8____78.5____77.1

    1/2 Depth Tread with ABS__________84.7____73.7____81.4

    Full Depth Tread without ABS_____111.1___110.2___108.6

     

    1997 Ford Ranger

    Full Depth Tread with ABS_________83.8____81.5____79.8

    1/2 Depth Tread with ABS__________91.5____89.4____84.6

    Full Depth Tread without ABS_____131.9___126.0___118.4

     

    #############################

     

    0.05 Inch Wet Macadam Surface

    (Stopping Distance in Feet)

     

    2001 Dodge Grand Caravan Sport__20 psi__28 psi__35 psi

    Full Depth Tread with ABS_________80.0____81.1____82.7

    1/2 Depth Tread with ABS_________103.7____99.7____92.2

    Full Depth Tread without ABS_____118.0___112.2___111.7

     

    1997 Ford Ranger

    Full Depth Tread with ABS_________89.7____86.0____81.5

    1/2 Depth Tread with ABS_________125.7___118.5___104.5

    Full Depth Tread without ABS_____142.9___134.8___125.7

     

    #############################

     

    Specialty snow tires on specific snow conditions are, obviously, a special case, but it has nothing to do with the general behaviour of the average passenger tire in most conditions. It also doesn't cover slush where again, the ability to bring maximum point pressure to bear is more important than a big footprint.

     

    Manufacturers set the vehicle 'recommended' pressure for many reasons besides safety and performance. Remember the Bridgestone fiasco with Ford. Ford recommended a low pressure on the Exploder, because it decreased the chance of rollover (at least partially because you couldn't corner as fast with the sidewalls rolling over :) ). But, that caused the tires to blow out. Bridgestone took the heat, but it was Ford's fault. The tires were rated for higher inflation, and should have been run there.

     

    Most instances now where the vehicle manufacturers recommend lower tire pressures are for comfort.

     

    But, in the vast majority of real world situations you will get better performance and longer tire life by going closer to the sidewall rating. The possible exceptions being mud and some rare snow situations where you are looking more for a snowshoe than a tire. But, Slush, Ice, and Plowed snow all benefit greatly from higher pressure.

     

    What's really bad is when people buy into this 'big footprint' myth and let air out of their tires in the winter :(

     

    I'm not saying to always inflate tires to the sidewall max, but 99.9% of the time you'll do far better to inflate a bit over what's printed on the vehicle. I know many tire professionals who use the '5 Pounds Over' rule on their own cars. IE, if the vehicle manufacturer wants 28 pounds in the tires, they do 33. If the manufacturer wants 32, they do 37.

     

    This has another benefit. It makes sure you don't run under-inflated, because it's ALWAYS far safer to be a few pounds over than a few pounds under.
  • quasar4quasar4 Member Posts: 110
    What's more important safety - as in better control and braking, or mpg? Since many of you are talking about how to save the tiniest bit of gas by not warming up the vehicle and running the heater til warm, I'd guess you're not advocating snow tires?

     

    --Talk about gross assumptions! You're missing the whole point of this forum, kernick. It's not, "Hybrid tips: Optimizing Safety." It's all about Fuel Economy, baby. Your comment is like telling a NASCAR driver that he doesn't care about safety because he and his mechanic happen to be having a discussion on how to make the car go faster. I would hope that people would have half a brain to use common sense when choosing whether or not to implement some of the suggestions presented in the forum. If you're dying of hypothermia, for example, by all means don't let my fuel saving tip stop you from turning on your heater. I don't want to be accused of cold-blooded murder...haha.

     

    --About the braking: unless I miss my guess, no one was advocating screaming up to a stoplight and braking only at the last possible second. I believe the other gentleman was simply saying that from a fuel economy standpoint, it's better to coast gradually up to a stop letting the car slow itself and gently braking when necessary to come to a rest, rather than flying in and relying heavily on the brakes to do the job. In fact, safety-wise, if you're talking about ice, this would be a much better way to come to a stop since the momentum change would be gradual. Who's to say that when you're "testing" the brakes you're not already on black ice? Then you may very well spin out and swipe the guy next to you. Again, judicial use of the grey matter is probably the best tip I can give.
  • xcelxcel Member Posts: 1,025
    Hi Tempusvn:

     

    ___Excellent post. I hope you don&#146;t mind if I spread that all over the net ;-)

     

    ___Here is one for the rest of us …

     

    http://www.hydrogen-boost.com/february2002.html

     

    ___Personally, 50 #&#146;s (6 over Max Sidewall is my own norm) and you can take the 75,000 miles at those pressures anyway you want. Since I am not racing up to stoplights, am not driving at much over the speed limits if at all, my braking distances will be far shorter no matter what pressures I was running at.

     

    ___As a tip, my best stops happen when I don&#146;t use the brakes at all. It requires really good timing of course but here is an example … You are cruising down the highway at 60 mph. You have an upward sloped off-ramp. Average height at the top of the ramp is ~ 30&#146; or so. Let off the gas ~ ¼ mile before and not only have you bled off the 10 - 15 mph by the time you hit the ramp (60 mph down to 45 mph or so), sometimes you can bleed off the rest of that 45 mph to 0 mph with quite a bit of your Kinetic swapped for Potential just as you hit the stop sign at the top of said off-ramp. No brakes, maximum FE, and in case the ramp were slick from ice and snow, very very safe. It works with lights, signs, off ramps, and traffic obstructions up ahead.

     

    ___This is just one of the tips I like to pass on to help others achieve higher FE by simply stating the obvious. Drive like you don&#146;t have brakes and your FE will improve to hypermiler status almost immediately.

     

    ___Good Luck

     

    ___Wayne R. Gerdes
  • gagricegagrice Pahrump, NevadaMember Posts: 31,450
    stating that their Michelin Arctic Alpin has a "high contact tread-design and expanded contact patch".

     

    Maybe the name is wishful thinking on Michelin's part. I personally use Michelin's on my Suburban. In the Arctic the only tires that seem to hold up in the extreme cold and harsh roads are Toyo & Bridgestone. When they send up a new vehicle with heavy duty tires meant for the rest of the world they get replaced the first year. The gravel and cold rip them to shreds. If you get 5k miles up there on OEM tires it is considered good. I have never seen a Michelin used in the Arctic. Tall hard compound 10 ply tires are what are generally used. That is all the tire guys carry.
  • quasar4quasar4 Member Posts: 110
    ...let's not tread too far down the snow tire path in the "Hybrid Tips: Optimizing Mileage" forum unless you're specifically addressing fuel economy.
  • mistermemisterme Member Posts: 407
    My point is not that the HCH heater is ineffective, quite contrary it can blow heat in a very short time.

    It provides cabin heat more quickly than our other vehicle which consumes 3x the fuel.

     

    I think allowing the engine to concentrate on heating itself up completely before sharing it to the cabin works for all vehicles , not just HCH.

    (Except Prius which uses electric)

     

    If an engine can reach its operating temperature faster, that warmed up engine gives better MPG.
  • kernickkernick Member Posts: 4,072
    Good explanation, and probably true. Now how long would it take a Prius to warmup if it's -5F out? How does a Prius warmup if the engine shutsdown when stopped. Would one put a brick on the accelerator, and go back in the house for a cup of coffee?

     

    At least you should always have enough battery power to get the engine started. ;-)
  • kernickkernick Member Posts: 4,072
    Since millions of us are being buried with snow tonight, and millions of Canadians are stuck with snow and ice for months, I ask if you guys suggest or are running snowtires. Do you accept the lower mpg a snow tire will give you, or do you take your chances with the stock all-season(?) tires? and are you running significantly increased pressures?

     

    What you give me first is tell me I'm wrong concerning snow-tires. When I prove otherwise, you then post data - which is good data, but has nothing to do with snow tires, and add "Specialty snow tires on specific snow conditions are, obviously, a special case, but it has nothing to do with the general behaviour of the average passenger tire in most conditions."

     

    Well gee, since I was talking about a specialty case, and then you comment on it, I'll just assume that you missed my mention of "snow" in front of the word tire. And you were correct all the time, just about something else. ;-)

     

    And you're right that I never mentioned about lowering the tire pressure either on a regular or snow tire. I suggest just as the NHTSA to use the manufacturer's recommended pressure, or a few psi higher (I believe they recommend a max. of +4psi).
  • tempusvntempusvn Member Posts: 119
    Sorry for any confusion Kernick. You're right, I wasn't addressing snow tires. I specifically quoted the portion of your post I took exception to. It didn't seem to me to be a specific statement about snow tires but about tire inflation in general, since it was set off in a separate paragraph and prefaced with an "Also".

     

    Where I live, good modern all season tires like Michelin Hydroedge or Goodyear TripleTreds are adequate for any snow situations where sane people would be driving. In areas that don't get regular, long-lasting snow, the danger isn't your sliding, but the 'other guy' who doesn't know how to drive on snow or ice. Given the driving skills of people locally, I just stay off the road when it's to the point that actual snow tires would be required.

     

    I've lived in snow country too, and there's clearly a time and place for snow tires. In fact, I'd like to see more places re-legalize studded tires because modern studs don't chew up pavement nearly as much as the old versions.

     

    Yes, you lose mileage with snow tires on dry pavement, but you lose mileage with any tire in snow anyway.

     

    If you're driving on snow or ice 80% of the time, it may make sense to run snow tires.

     

    If you're driving on dry pavement 95% of the winter, and on minimal snow and slush the rest of the time, good all-seasons are fine.

     

    But, either way, I'd still keep them well inflated.

     

    There's a reason the old VW Beetles were monsters in snow. It's because they had skinny tires that were hard as rocks :)
  • mistermemisterme Member Posts: 407
    "How does a Prius warmup if the engine shutsdown when stopped"

     

    Once again, I've heard from many sources that the Prius does not use engine heat, but rather an electric heating element(s).

     

    Prius heating is independent of engine temperature.
  • stevewastevewa Member Posts: 203
    The Prius uses an electric heating element as a supplement to the regular heater. It does not use electric heat exclusively...electricity is a very inefficient way to heat things (ask anyone with an electric water heater). One of the design considerations of the Prius is that minimum emissions are achieved when the engine (and more importantly the catalytic converter) are up to normal operating temperature. Therefore if the engine is cold it will run until warmed up.

     

    Perhaps you are confusing heat with AC? The 2004+ Prius use an electrically powered Scroll-type compressor for their AC (2001-2003 used a conventional belt-driven compressor).
  • mistermemisterme Member Posts: 407
    Thanks stevewa for clearing that up!
  • railroadjamesrailroadjames Member Posts: 560
    I understand the heater sys. I just don't think it delivers enough heat nor is it quick to get it to the cabin when it gets really cold. Then there's the problem of a loss of MPG's that I'm pretty sure has to do with the heating sys. Milage drops off considerably in cold weather at least until the car gets up to normal operating temp (15 mins or there abouts). My wife and I seldom agree on many many things but one we do agree on is that the controls to the heater sys. are frustrating. You have to go to the screen for most controls and then there's the additional frustration trying to figure out the screen's touch controls and how to get just what you want while driving. Also, the screen for heater sys. only stays up for a few seconds and you have to punch it up again. So .. I'm directing this to TOYOTA... Like my Grand Dad once said... K-I-S-S... Keep It Simple Stupid. There are several things that this applies to when it comes to the Prius. That's another day.

    Culliganman (sometimes complexity breeds frustration)
  • stevewastevewa Member Posts: 203
    Hmmm, the "classic" Prius has a much simpler system, a thermostat, a mode control and a fan control, all real knobs you can turn with your own fingers.

     

    Sounds like the jury's out on the "improved" climate control in the 2004+ models.
  • electrictroyelectrictroy Member Posts: 564
    "-----Would the mere act of using the heater reduce the efficiency of the engine in the winter by pulling waste heat away from it" "-----If the cold weather has a negative effect on battery efficiency, then would it make sense to keep the cabin as warm as possible in the winter so as to warm up the battery pack?"

     

    .

     

    NiMH batteries like being cold. Plus, the DC/DC converter throws off plenty of heat into the battery compartment... you don't need to add to that.

     

    As for heating vs. engine efficiency, I think it depends on your engine. My 220 hp Avenger burns through tons of fuel & has tons of heat to spare. I could turn my car into an oven, and there'd be no impact on my 30 MPG average.

     

    In contrast, my 67hp Insight barely has enough power to move the car down the road... it's throwing off almost no waste heat... so if I turn on the cabin fan, my little engine will cool off & end up burning more fuel to compensate.

     

    troy
  • quasar4quasar4 Member Posts: 110
    --Thanks for the input. Seems to make sense. Then I guess it's official: to optimize fuel economy with a low hp engine in cold weather, don't run the heater. Or maybe more practically, if you need to crank up the heat, wait a few minutes to let the engine warm up first.
  • cablackcablack Member Posts: 45
    Sorry for this somewhat regional question, but: what do you folks know about "winter gas" that they apparently sell in CA, if not in other states?

     

    I have heard that it is oxygenated, which reduces pollution in older cars, but results in poorer gas mileage across the board. And so I've been assuming that my mileage will improve once spring rools around.

     

    But I don't know for sure, so I'd love to hear what you folks know about it.
  • Kirstie_HKirstie_H EdmundsAdministrator Posts: 11,132
    You might also ask in our Fuel types & gas mileage discussions - a few Californians check in there.

    There was also a brief conversation about oxygenated fuel starting with this post:

    marklud, "What about fuel types & gas mileage?" #55, 27 Dec 2003 2:28 pm

     

    kirstie_h

    Roving Host

    Host, Future Vehicles & Smart Shopper discussions

    MODERATOR

    Need help navigating? [email protected] - or send a private message by clicking on my name.

    Share your vehicle reviews

  • cablackcablack Member Posts: 45
    You might also ask in ...

     

    Thanks for the pointer! I followed your advice and posted the question over there.
  • railroadjamesrailroadjames Member Posts: 560
    Again ....a little more explanation. If you are sitting in the 2nd Generation Prius cars allowing them to warm up in frigid cold weather understand that, if you have the secondary screen up (the one without the wheels) you will notice that the MPG's (overall) go down a tenth at a time about every 30-40 seconds. Also understand that in those really cold temps the ICE engine runs considerably much more than it does in spring , summer, and fall. This you come to accept in the Prius. Is this a failing? I think not. I've yet to see any car that doesn't show a decrease in economy and/or performance in severe cold.

    Culliganman (cutting the Prius some slack)

    P.S. Ever notice the car mags always road test cars in somewhat ideal temps and weather conditions?
  • stevewastevewa Member Posts: 203
    We have oxegenated fuel in the Portland, OR area every winter. Most cars take at least a 2-5 percent hit on mileage when it's in use. Portland will stop using the special fuel in 2007 as we have not had the problems with clean air action days in wintertime lately.
  • timber104timber104 Member Posts: 24
    Anyone know about the recent story in the news about having the air removed from your tires and having hydrogen put in? The story went on to say you will get better mileage, longer lasting tires, and less damage to the inner rim.

    Does anyone know if this was true?
  • gagricegagrice Pahrump, NevadaMember Posts: 31,450
    It sounds a bit far fetched. My understanding is that hydrogen is very difficult to keep from leaking. One of the negatives to hydrogen fuel cells.
  • xcelxcel Member Posts: 1,025
    Hi Timber104:

     

    ___I am sure the article mentioned N2 (78% of what is in your tires right now is N2) as many people are doing this now, not H2. You would be filling up every third day (not cheaply either ;-)) if H2 was in the carcasses.

     

    ___Good Luck

     

    ___Wayne R. Gerdes
  • gagricegagrice Pahrump, NevadaMember Posts: 31,450
    Nitrogen makes sense. That is what we use to keep pressure on telephone cables and radio waveguides.
This discussion has been closed.