Warming up a vehicle prior to driving it?

Discussion in 'Start Your Journey Here' started by regor, Oct 24, 2008.

  1. regor

    regor Active Member

    I live in San Diego. Poway to be exactly. Even on the coldest days, it rarely gets below 30 degrees. I drive (not at the same time, of course) a 08 Honda Civic and a 01 Chevy Silverado. Both use Mobil-1 synthetic oil. There are 2 schools apparently to when a person should actually drive a vehicle after starting it up. Some will let a car warm up to operating temp before driving it, and some will start the vehicle and drive slowly away for the first several miles as the vehicle warms up.
    I tend to be in the start it up and drive it school and the reason why I’m in that school, is I was informed many years ago that using Mobil-1 (In fact any good synthetic oil), there is a thin layer of oil that is left on the internal engine parts that will make start up wear zero.
    Is that true? Do the vehicle owners that start and drive their cars slowly for the first several miles, are they smart, or are they causing damage to their vehicles by not letting them warm up before driving away.

    BTW, my commute is 81 miles RT, from 500’ to 4500’.
     
  2. Kacey Green

    Kacey Green Well-Known Member

    Not quite zero but significantly reduced wear according to the info I've be given on the layer of oil theory.

    Start you vehicle, the buckle up, now the car is ready to drive. Or you can wait until the RPMs drop a hair and that is way more than needed. I can't see any reason to let it get to full temp before moving.
     
  3. abcdpeterson

    abcdpeterson Well-Known Member

    Chuckle… I drive it then start it. :D

    Push out my garage, cost down the driveway, cost down the block.
    Then when I see the stop sign:
    -No cross traffic, bump start, quick stop at the sign, off I go.
    -cross traffic, stop, key start, off I go.

    I don’t lug the engine, but I keep the rpm’s lower until warm. Mostly due the fact FE is so bad with the cold engine.
    It’s also in the back of my mind to take it easy on that cold engine. It got beat into my head hard when I started driving to allow the car to warm up. Everything I am reading says that is not the case now with cars, but it’s a hard habit to break.
    So my compromise is to just take it easy while warming up.

    In fact I always thought if your going to idle the car to warm it up, why not idle in gear?
     
  4. Shiba3420

    Shiba3420 Well-Known Member

    Cars don't really need to warm up, however it is to their benefit to get oil circulating. That takes just a few seconds. Short of dragsters and other race cars, no car needs to warm up more than 30 seconds, and usually you can get away with no warm up at all. Just don't punch it, right after turning the key....but hypermilers wouldn't punch it anyway, right?
     
  5. Tomjones76

    Tomjones76 Well-Known Member

    Carmakers say start it and drive it.
    I say start it, but keep it under very light throttle and under 22000 RPM for at least the first 1-2 minutes.
    To echo another poster, there's no reason warm-up shouldn't be in gear.
    As far as oils go, 5W oils are good down to -25 F, and M1 5W30 is technically good down to even lower temps.
     
  6. brick

    brick Answers to "that guy."

    Your car must be a lot more fun than mine in that 3rd minute. :D
     
  7. Tomjones76

    Tomjones76 Well-Known Member

    Hahahahaha. Good job catching that.
    "Here's Tomjones76, observe him trying to Hypermile in this Honda Formula 1 car where he's removed the pansy rev limiter it was given at the factory......"

    I can safely say that neither of regor's vehicles is likely to have a problem with wasting gas by exceeding 22,000 RPM.........
     
  8. 98CRV

    98CRV Well-Known Member

    My warm-up is about 1/8 sec. I do all elements of the pre-drive ritual, fire her up and before the tach drops, I'm jetting off to 15, heck 20 mph if I'm feelin' racy....
     
  9. HAFNHAF

    HAFNHAF Well-Known Member

    neither my insight nor my wifes caravan will warm up without driving. without a load on the engine(s), they hardly get warm at all. get in, buckle up, turn the key, go (gently).
     
  10. laurieaw

    laurieaw Sorceress of the North

    i am of the get in and drive school. the only time i have a small exception is that when it's -20 or so, i really need a minute or two before i can get the shift to work. even with the block heater, those kinds of temps really make the car stiff.
     
  11. Tomjones76

    Tomjones76 Well-Known Member

    Based on posts on other forums, the fuel burn rate at idle on many vehicles is low enough that the engines will NEVER get up to operating temperature, and in fact if you idle at 600-800 RPM for extended periods you'll wind up inadvertently screwing up the engine because it's just not at operating temperature.
    Now, no one on this board would ever do it, but if you need to idle a vehicle for an extended period (operating emergency lights/accessories, perhaps) or need to bring a vehicle up to operating temperature without moving it (why would anyone do that??) the solution is to idle at 1800 or 2000 RPM, which actually maintains an operating temperature.
    You'll note that modern ambulances and police cars frequently have a high idle switch that can be used in certain circumstances; you'll idle at much-higher-than-normal RPM once you press those.

    I suppose, if you actually had to warm your car up quickly before driving it, you might be better off doing so at high idle.
    Still, I shudder to think of doing this. I think I saw a tractor-trailer fleet manager who had to run his vehicles at high idle before driving them, but that guy had the disadvantage of being in Canada, in the winter, and having a vehicle that was going to be forcing a loaded trailer up a big hill within two minutes of leaving his parking lot.
     
  12. brick

    brick Answers to "that guy."

    Before I came to CleanMPG, I did an experiment to see if idling would improve fuel economy vs. driving cold. I basically let the thing (an Accord at the time) sit there until the needle started to move, at which point I drove off. The results were abysmal. Not only did it waste time, but gas mileage dropped into the mid 20s from an average of about 30mpg. Just start the car, put it in gear, and drive gently while temperature is coming up.
     
  13. slichopshop

    slichopshop SLiChopShop

    My old honda civic with automatic tranny has to warm up for 1-3 minutes before the rpm's go down enough to put into gear without ripping out the cv joints..... Good thing gas prices have gone down
     
  14. PaleMelanesian

    PaleMelanesian Beat the System Staff Member

    Me too. Any extra idling moves you to the right on this graph. Even when I never reach full operating temperature, less engine run-time is better for fuel consumption. Extra warmup will not save enough fuel later to come out even, much less come out ahead.

    [​IMG]

    I do have better mileage by choosing the route with a slow and gentle first mile, compared to the other route which dumps right onto a crowded 55 mph highway.
     
  15. lamebums

    lamebums Member

    Idling gets zero miles per gallon. Don't throw away any fuel. :(

    I drive, then pop the clutch to start at the bottom of the first hill. The engine is always either 1) Pulse, 2) DWL, or 3) off. That's the end of it.

    When cold I keep the engine under 1500 RPM's to avoid throwing away fuel just for the sake of warming up the catalytic converter.
     
  16. The Fridge

    The Fridge Well-Known Member

    The way to warm up your engine is with a block heater...
     
  17. BudgetFitting

    BudgetFitting FAS Convert

    On my last fully built race engine, I would have to let it idle until it reached normal operating temperature due to the different expansion rates of the pistons and sleeves/block. Absent this type of engine, letting it warm up before driving is not needed.
     
  18. jdhog

    jdhog Hyper Smiler

    I always get in and go. I don't know if there's any truth to this, and something not mentioned, but I was thinking that by starting up and getting moving quicker, you will help lubricate the engine by the oil sloshing around more than if it was sitting in the driveway idleing stationary. That might be just nonsense though.
     
  19. jcp123

    jcp123 Caliente!

    Start and go. My car's carbureted, so I give it a few seconds to clear its throat, but even that's rarely more than 5 or 10 seconds, if that.
     
  20. 98CRV

    98CRV Well-Known Member


    Are you truly hypermiling that Mustang or just drivin' slow so that everyone can see you :)? That's what I'd do. I'd be at 50 mph, smilin' and wavin'.
     

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