A/C and Gas Milage

Discussion in 'Trucks and Trailers' started by ColePyck, Jun 14, 2007.

  1. ColePyck

    ColePyck LawnSite Member
    from Midwest
    Posts: 208

    Two things. Do you really get better gas miliage with the A/C off? and I always tell my guys to turn off the AC before you shut off the truck so the compressor wont have hard starts and stops, they never do. So today I pulled the AC Relay Fuse.......I told them not sure what happened but I will get around to fixing it!
     
  2. David Hartzog

    David Hartzog Banned
    Posts: 531

    my wife insists this is a myth and that rolling the windows down creates resistance. i think shes a wimp and just wants the a/c on.

    i dont have the same problem in my truck right now cause my a/c is out and its an oven in there!
     
  3. DBL

    DBL LawnSite Silver Member
    Posts: 2,219

    my grass crew says they only run the a/c from the last lawn back to the shop but i think they run it all day...i cant be there all the time to watch and im not pulling the fuse so i guess theyre running it
     
  4. fiveoboy01

    fiveoboy01 LawnSite Silver Member
    Posts: 2,988

    A/C does indeed reduce fuel mileage. The compressor is a parasitic load on the engine. Energy has to turn the compressor somehow.

    Turning the A/C on or off before or after stopping the truck will have no effect on compressor operation.
     
  5. Supper Grassy

    Supper Grassy LawnSite Bronze Member
    Posts: 1,582

    If i recall correctly Mythbusters tried this and it SURPRISINGLY turned out that a/c on is better gas milage
     
  6. Albemarle Lawn

    Albemarle Lawn LawnSite Bronze Member
    Posts: 1,544

    The engine is warm and the cab is cool.

    Want them to enjoy their jobs. Not worried about the gas, they make more every day.


    The only reason to turn A/C off first is to prevent fungus and odors from the A/C...turn off the A/C but let the vents blow to warm the evaporator so is doesn't sweat as much for hours after the truck is parked.
     
  7. cat2

    cat2 LawnSite Senior Member
    from Mi
    Posts: 891



    No. I seen that one and the one with the a/c turned off is better on gas. The one with a/c off did 30 more laps.
     
  8. Petr51488

    Petr51488 LawnSite Silver Member
    from NJ
    Posts: 2,372

    If you're doing highway speeds then the a.c is better then having the windows down. If you're doing city driving, having the a/c kills the mileage like you wouldn't believe. Especially when you have a loaded trailer with grass in the back of the truck. Sometimes its all worth it when its 100 degrees outside.
     
  9. Midwest Lawn Services

    Midwest Lawn Services LawnSite Member
    Posts: 211

    That sounds much more logical.
     
  10. zz4guy

    zz4guy LawnSite Senior Member
    Posts: 901

    Just my opinion, but don't you think it's worth the extra $2/day or whatever to keep your employees happy? It sucks out there in the summer time!!
     

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