Hypermiling

Discussion in 'Community Discussion' started by Roger1, Apr 22, 2007.

  1. Roger1 macrumors 65816

    Roger1

    Joined:
    Jun 3, 2002
    Location:
    Michigan
    #1
    Hey all!
    I've been reading the threads about gas prices, and "how many MPG do you get? Shecky posted a link about hypermilers. For those of you who don't know, these are people who go to rediculous ends to eke out the last mile from a gallon of gas. I thought this was pretty cool for the most part. So I decided I would try a little "hypermiling" myself. I'm not going to go to the extremes these people do (something about drafting a few inches from the back end of a semi makes me nervous).

    Anyway, I will drive the speed limit, do some drafting behind semis (several car lengths, of course), and turn off my car when driving down hills. I will also forgo A/C if it gets hot, and drive with the windows up. I currently get 36-39 miles per gallon. I will start tomorrow morning, when I fill up my gas tank. Normally, I am just under 200 miles at the 1/2 tank mark. I will let you know how I'm doing later in the week.


    Link:http://www.hypermiling.com/
     
  2. CanadaRAM macrumors G5

    CanadaRAM

    Joined:
    Oct 11, 2004
    Location:
    On the Left Coast - Victoria BC Canada
    #2
    Note> that this is not legal in some jurisdictions - and can be downright dangerous in cars with power brakes and steering.
     
  3. pseudobrit macrumors 68040

    pseudobrit

    Joined:
    Jul 23, 2002
    Location:
    Jobs' Spare Liver Jar
    #3
    Some of that stuff is nuts, and the rest is common sense.

    It's best to know what the torque map of your engine looks like. Then try to keep the motor in the lowest gear possible while maintaining a reasonable level of torque.

    When I'm in gear and my foot is off the accelerator the ECU asks for 0mg of fuel delivery. Of course since my crankshaft is still turning and my car is still on I have vacuum for the brake and steering servos, and won't cause an accident if I have to stop or manoevre suddenly. And I won't kill my starter by using it twice a mile.

    Turning off the car while travelling downhill is madness.
    Driving closely behind a semi gets your windshield cracked.
     
  4. nickster9224 macrumors 6502a

    nickster9224

    Joined:
    Nov 6, 2006
    Location:
    35 Miles From Chicago, Illinois
    #4
    i dont see how it save gas turining it off down hills, when you use a signifigant amount of gas starting your car
     
  5. pseudobrit macrumors 68040

    pseudobrit

    Joined:
    Jul 23, 2002
    Location:
    Jobs' Spare Liver Jar
    #5
    Even if it doesn't it's dangerous and murder on your starter.

    I have a sixth sense for fuel savings using inertia and conservative braking/acceleration from bicycling, where a touch of the brakes bleeds off speed that (eventually) is only won back by physical exertion. When it's literally a pain to overcome inefficient habits on a bike, you learn quickly.
     
  6. Counterfit macrumors G3

    Counterfit

    Joined:
    Aug 20, 2003
    Location:
    sitting on your shoulder
    #6
    I think you mean highest. Everyone messes that up. 1st = short (low) 5th/6th = tall (high). But the point is the same, pick the highest gear you can to keep the revs lower.

    Agreed. In my state, even being in neutral is illegal.

    If you're close enough, your radiator gets hit first. :D
     
  7. mkrishnan Moderator emeritus

    mkrishnan

    Joined:
    Jan 9, 2004
    Location:
    Grand Rapids, MI, USA
    #7
    Is this technically correct? Isn't the minimal fuel delivered by the injectors always enough to make the cylinders fire, at the least (or are you talking about a vehicle that uses a non-standard engine cycle?)? I don't think the fuel delivery ever goes to true zero while the engine is turning.
     
  8. Roger1 thread starter macrumors 65816

    Roger1

    Joined:
    Jun 3, 2002
    Location:
    Michigan
    #8

    I try doing the gear thing, and it works some, so I will continue doing it. As for going down hill with the engine off, I don't have any really BIG hills, so I figured I'd try it. If I lived in Colorado or somewhere, probably not. As for being close to semis, again, not TOO close. Several car lengths, at least.

    Edit: I won't be doing a lot of this stuff with other traffic around (downhill coasting, etc) because this IS Michigan, and the speed limit seems to be more of a suggestion than a law
    :p
     
  9. pseudobrit macrumors 68040

    pseudobrit

    Joined:
    Jul 23, 2002
    Location:
    Jobs' Spare Liver Jar
    #9
    Whoops, that's my oversight. I was indeed thinking about low revs while writing about the gears.
     
  10. pseudobrit macrumors 68040

    pseudobrit

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    Jul 23, 2002
    Location:
    Jobs' Spare Liver Jar
    #10
    I don't know if you'd call it non-standard, but it's a direct injection diesel cycle. The computer cuts off fuel injection on engine overrun.
     
  11. twoodcc macrumors P6

    twoodcc

    Joined:
    Feb 3, 2005
    Location:
    Right side of wrong
    #11
    i actually started doing this (or some of it) after reading the link for the other thread.

    my overall average before trying this was just over 23 mpg in my tacoma, and i got 27.7 when i filled up yesterday :) . but basically i just use cruise control on the freeway (well basically any road that i can) and keep it below 60 mph (i got the best at like 52 mph, so i'm guessing the lower the better, since my truck sits up higher and therefore more wind resistance)

    and i also have a scangauge2 in my truck, so that helps me monitor my mpg

    i do coast, but i don't turn off the truck. and it's a manual
     
  12. SkyBell macrumors 604

    SkyBell

    Joined:
    Sep 7, 2006
    Location:
    Texas, unfortunately.
    #12
    Actually, it's suggested that you turn off your car if you are going to be idleing for more then 10 seconds (unless you are at a stoplight, of course) Because in most cases, 10 seconds of idleing is how much gas it takes to start your car.
     
  13. Bill Gates macrumors 68020

    Bill Gates

    Joined:
    Jun 21, 2006
    Location:
    127.0.0.1
    #13
    However, that can be just as bad overall as letting it idle. When you first start your car, you have no oil pressure. The second it takes to build oil pressure is when a lot of wear and tear occurs. Not to mention wear on the starter and battery. I live by the 5 or so minute rule instead of 10 seconds due to this.
     
  14. Abstract macrumors Penryn

    Abstract

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    Dec 27, 2002
    Location:
    Location Location Location
    #14
    I can't even do that in my car. I can't restart my car unless I'm in park (P).
     
  15. iGav macrumors G3

    Joined:
    Mar 9, 2002
    #15
    Don't forget to fold in the wing mirrors and remove the front and rear windows. ;) :rolleyes: :p
     
  16. Roger1 thread starter macrumors 65816

    Roger1

    Joined:
    Jun 3, 2002
    Location:
    Michigan
    #16
    They're power mirrors. It would take too much energy to take them off. At least as much as it would to wash the car :p

    Anyway, I started this morning, just trying to do the speed limit. It's amazing how many cars line up behind you doing 55 mph (in a 55 zone). It's difficult trying to stay at the speed limit while they are doing that.

    Anywho, time to start work.
     
  17. iGav macrumors G3

    Joined:
    Mar 9, 2002
    #17
    If you really wanted to make a difference... use sellotape to tape up the panel and shut lines.

    Fit economy run-flats, this way you'll also shed weight by not requiring a spare, and all the associated ancillaries.

    Run your tyres several psi higher to reduce rolling resistance.

    Only fill up with enough petrol to cover your journey. Don't brim it.

    Remove mudflaps/guards for the summer months.
     
  18. takao macrumors 68040

    takao

    Joined:
    Dec 25, 2003
    Location:
    Dornbirn (Austria)
    #18
    don't shut off the engine while driving downhill, especially in newer cars with power assisted steering and braking
    shutting off AC can be a big gas safer though: around 10% as far as i remember
     
  19. mkrishnan Moderator emeritus

    mkrishnan

    Joined:
    Jan 9, 2004
    Location:
    Grand Rapids, MI, USA
    #19
    Ahhh, sorry, for diesel, that makes sense. I thought you were talking about gasoline / petroleum.
     
  20. twoodcc macrumors P6

    twoodcc

    Joined:
    Feb 3, 2005
    Location:
    Right side of wrong
    #20
    don't give in to them! if you want to drive 55 in a 55, then do it
     
  21. pseudobrit macrumors 68040

    pseudobrit

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    Jul 23, 2002
    Location:
    Jobs' Spare Liver Jar
    #21
    Don't forget fender skirts.
     
  22. yg17 macrumors G5

    yg17

    Joined:
    Aug 1, 2004
    Location:
    St. Louis, MO
    #22
    I get low 20s city and high 20s highway, and have decided that getting more out isn't worth it. The cost is negligible, and I like being comfortable while driving. That means not sweating my arse off, and looking at the speedo every second to make sure I'm not a single mile above the speed limit. I like having fun....I like flooring it from stops, I like redlining 1st and 2nd every now and then, I like getting closer towards triple digits while on an empty highway, I like taking corners and curves while going fast. And rather than stay behind semis, I do everything I reasonably can to get in front of them, I hate being around them.
     
  23. twoodcc macrumors P6

    twoodcc

    Joined:
    Feb 3, 2005
    Location:
    Right side of wrong
    #23
    what do you drive?

    i like to do some of those things also, but not all the time. especially with how gas has gone up. right now i'm doing this to save a little money, especially since i'm in college right now with no job. but the summer is almost here, and then i can work some and make a little money
     
  24. yg17 macrumors G5

    yg17

    Joined:
    Aug 1, 2004
    Location:
    St. Louis, MO
    #24
    Hyundai Tiburon.

    I've gotten more than 30mpg highway out of it, but I don't drive a lot, and the cost savings that I would get out of driving like grandma would be negligible. If I was filling up every day, things might be different, but I can go 2 to 3 weeks without filling up since I only have a 2 mile drive to work/school each day and the occasional grocery store run.
     
  25. Roger1 thread starter macrumors 65816

    Roger1

    Joined:
    Jun 3, 2002
    Location:
    Michigan
    #25
    I was thinking of Astroglide, myself. Just to make it slip through the air better.
     

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