taking off from dead stop

Discussion in 'Fuel Economy' started by joesgot4, Dec 15, 2014.

  1. joesgot4

    joesgot4 Well-Known Member

    ive been confused in this area for a long time and need advice, ive tried crawling up to speed and briskly getting to speed, what do yall think is most efficient way to get up to speed to get into high gear? i can get really good highway numbers ,but despite my efforts havent learned how to get better mileage in town. i turn car off at lights and coast whenever possible, just cant seem to get over 35 mpgs when i go through a whole tank in town. any advice is appreciated
     
  2. jcp123

    jcp123 Caliente!

    I find that moderate acceleration is usually the best way to get up to speed. The only place I have found that not to be the case is going from a dead stop into an uphill climb, where it seems that gathering speed more quickly and then maintaining the high gear seems to be slightly more efficient.
     
  3. 08EscapeHybrid

    08EscapeHybrid Moderator

    The most energy is used in the transition from a stopped vehicle to a moving vehicle. I take my foot of the brake and let the vehicle take off on its own instead of immediately hitting the go pedal. After I'm already moving, I find that moderate acceleration is usually best. Too slow and you spend too much time in lower gears, and too fast and you just waste gas. Most vehicles I just give about 1/4 throttle to accelerate.
     
  4. litesong

    litesong litesong

    I'm averaging 39+ mpg with my 2013 Elantra, which was badmouthed for poor mpg. Pretty sure briskly accelerating isn't good for mpg. Accelerating as fast as most other drivers isn't good for mpg. As for my low torque(131 lbs-ft) Elantra, accelerating somewhat slower than average drivers, seems a good ticket to punch...... not the accelerator pedal.
     
  5. mbooradley

    mbooradley Member

    What kind of RPMs are you running? One of the biggest things I changed when I started this process was shifting MUCH earlier.
    M
     
  6. 2012 accent hatch? Mt or at?
     
  7. litesong

    litesong litesong

    litesong wrote:
    I'm averaging 39+ MPG with my 2013 Elantra, which was badmouthed for poor MPG.....As for my low torque(131 lbs-ft) Elantra, accelerating somewhat slower than average drivers, seems a good ticket to punch...... not the accelerator pedal.
    //////
    mbooradley wrote:
    What kind of RPMs are you running? One of the biggest things I changed when I started this process was shifting MUCH earlier.
    ///////
    litesong wrote:
    My elantra is a 6 speed automatic tranny. Its funny. With all those gears, the car is set to be in 5th gear by 30mph!!! Other economy car transmissions are set to do the same. Of course, if people accelerate briskly, auto transmissions stay in lower gears till much higher speeds, which most certainly is rotten for high mpg. So mbooradley.....altho I don't have a manual transmission, I CAN control at what rpms my auto tranny shifts by accelerating faster or slower. An aside: with an older CVT tranny, I could accelerate WITHOUT the engine rpms changing! I just set the engine rpms with the gas pedal & would accelerate to whatever mph I wanted, AND the rpms changed little. Often I would set my rpms UNDER 2000 rpm & had OK(but less) acceleration than the drivers around me. With the Elantra's regular auto tranny, the gears shift AND rpms change. However, as the CVT taught me, I set my acceleration & get the tranny to shift a bit over 2000 rpms. But most of my acceleration is while the engine is below 2000 rpms. Now, my 6th gear can be engaged by 43mph, if while accelerating, I ease off the throttle. Once the 6th gear drops into place, my rpms are 1400 rpms. With careful re-application of the throttle, I can remain in 6th as I accelerate again. Also, if I'm in 6th gear & carefully slow down, the auto tranny holds in 6th gear till 35mph(& rpms are 1100). Therefore, my mpg can get outrageously good(car computer says 55+mpg), while driving around on 35mph to 45mph flat roads. Not bad for a car that people complain about its poor mpg.

    Yeah, I knew Elantra would be good before I bought it, despite all the bitchy people who won't drive it carefully. Oh, yeah, again. I use 100% ethanol-free gasoline(E0), that gets me 8%, 7%, & 5% better mpg than 10% ethanol blends.
     
    Last edited: Mar 11, 2015
  8. Sabrejet

    Sabrejet Member

    If it is a slight downhill, I let the car roll for a few meters. Then I light the ICE, shift to 2, and then back to D at 32 km/h; that is the minimum speed at which 3rd gear will engage. After that, I will speed up or FAS, depending on the situation.

    From a parking position, I will open the door slightly, and use my leg to roll the car for a few meters :D. Then light off, shift to 2, etc etc.

    Of course this is only for special circumstances; under usual circumstances, I will use about 1/3-1/2 throttle throughout, letting off the gas at 10 km/h, 32 km/h, and 52 km/h for the 2nd, 3rd, and top gear shift respectively. Lock up occurs somewhere north of 75 km/h.

    I really need to get some instrumentation; there is no way to tell how much I am burning during an accl :(
     

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