« History Of Hybrid Car
In Australia how fuel efficient are the vehicles people in the community use?` »

When sitting at a stop light for more than 30 seconds, should I shift into neutral or park for better MPG?

I own a 1994 Dodge Shadow ES (executive sedan) Automatic 2.2L 4 cylinder economy car. I use hypermiling to boost my Miles Per Gallon. One hypermiling technique is to shift your car into park or neutral when idling for more then 30seconds at a stop light. I have been trying this while placing my shadow in PARK. This has shown a considerable increase. Should I instead place it in NEUTRAL rather then PARK? NEUTRAL is just above DRIVE on the shifter and so it would be easy to change from NEUTRAL to PARK when the light turns green. When I placing it in park at a stop light there is a 5-10 second lag in the time it takes me to shift it to drive from the park position, so the cars behind me will have to wait to resume acceleration once the light turns green. Would placing it in NEUTRAL lead to better MPG then if I used PARK?

You have an AUTOMATIC.

When you are stopped, the transmission disengages from the engine anyway.

Go ahead and put it in neutral. You’re not accomplishing any single thing.

Unless you notice a HUGE difference in your rpm, the engine is behaving the exact same way, whether it’s D, Park, or Neutral. And since it’s behaving the same, gas mileage is the same.

People do this all the time, and don’t bother to put 5 seconds worth of thought into it.

This entry was posted on Tuesday, November 17th, 2009 at 9:40 pm and is filed under Hypermiling. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.

5 Responses to “When sitting at a stop light for more than 30 seconds, should I shift into neutral or park for better MPG?”

  1. neutral takes trans out of gear so does park/ really you sit at light and put it in park//cant do that in ny/nj/ no more car after the third light
    References :

  2. i wud assume neutral wud do the same as park and with the added benefit of not making u look like a jackass to the drivers behind u….so yea use neutral instead of park…..good luck
    References :

  3. Laksmana Andika Shah Putra on November 17th, 2009 at 10:51 pm

    agree
    References :

  4. You have an AUTOMATIC.

    When you are stopped, the transmission disengages from the engine anyway.

    Go ahead and put it in neutral. You’re not accomplishing any single thing.

    Unless you notice a HUGE difference in your rpm, the engine is behaving the exact same way, whether it’s D, Park, or Neutral. And since it’s behaving the same, gas mileage is the same.

    People do this all the time, and don’t bother to put 5 seconds worth of thought into it.
    References :

  5. Shifting into neutral or park is only good for longer stops. When you know for a fact that you can put in neutral (or parking), stay at neutral for at least three minutes, and only than shift back into drive and continue driving. For the same period, only about more than five-six minutes, it’s best to shut off the engine.

    Shifting into neutral for short periods of time will not improve MPG, due to constant fuel injection nessecary to keep a running engine when idling. Also, in most cars, the lubrication to the gearbox will cease, so don’t accelerate in neutral (it also burns-out the clutch plates and bends, if there are any) or park (also ruining the shaft and park pawl), don’t shift into these gears while still moving, don’t accelerate from a stand-still whilst left-foot braking.
    References :