Coasting in Neutral, Automatic Transmission

[thehunterooo]

http://www.aveoforum.com/forum/f106/...economy-11978/

[Thymeclock]

The article can't be absolutely true. If it was, then how do I average 35.5 mpg in my 04 Aveo using said techniques in over 90% city driving? The EPA estimates an average of 26 mpg.

To qualify that, I should mention that I only coast to minimize slamming on the brakes coming up to a stop sign or red light. If you use the coasting and slow acceleration to keep the car constantly rolling instead of starting and stopping frequently, your gas mileage will improve significantly. That is a no brainer.

If you feel it is an unsafe technique, then by all means do not use it. But it is needless and untruthful to argue that it doesn't save gas. It does. If you don't believe it, go here: CleanMPG, An authoritative source on fuel economy and hypermiling and here: Fuel Economy, Hypermiling, EcoModding News and Forum - Ecomodder.com Fuel Economy Forum, research the issue, then come back and tell me your findings.

Here is a rebuttal to AAA's findings that such techniques are unsafe: CleanMPG, - AAA Response An authoritative source on fuel economy and hypermiling

I'm not concerned with the driving technique of coasting in neutral being unsafe. I'm concerned with potential damage to the A/T.

If you take the A/T out of drive and coast with it in neutral to a stop or an almost stop, there will be no problem. That is known to be OK. However, if you do the same at a high speed (above let's say 60 MPH) and re-engage it back into drive at a speed above 50 MPH: the transmission will want to enter fourth gear and it is also programmed to be running with the torque converter engaged at speeds above 45 MPH.

What do you think will happen to the torque converter? Are you willing to risk damaging it, possibly incurring a very high repair bill, for the sake of saving a few cents on fuel?

[gclark8]

I will guided by the manual, low speed-coast-restart. Switching off in "N" at lights.

[daug1502]

Another advantage of manual transmission. I have been putting the gear selector in the neutral position quite a bit lately, or at the very least, driving in 5th when 4th or even 3rd is the normal gear. Then again at any speed for me it's a matter of pushing in the clutch selecting the gear i want/need and pressing the accelerator to the necessary RPM before I let out the clutch.
I know I have shifted other automatics into neutral while going 55+ and just waited until I could feel the deceleration of the transmission being engaged before I pressed the gas, let the car settle itself into the gear. I haven't driven an automatic aveo, so I don't know. If it was going to be hard on the car, i would think you could feel it.

[gone.m]

I haven't had to try that yet. I do almost no highway driving.

[DailyDriverMark]

If anyone goes so far as to shut the engine down while moving, please be aware...
You must be carefull with the key!!! It's only ONE CLICK BACK.
-One extra click and your steering wheel goes into lock mode. At 45 mph this can put you across a double solid yellow in a hurry.

[gone.m]

That's one of the reasons I'd really like to install a fuel cut off switch in the near future. That way the ignition uses fewer cycles, it's safer, and I could cut the engine without losing my headlights at night. Still not sure where I'd put the switch so it's easily reachable but not in range of being accidentally hit. Nobody wants the engine suddenly shutting down while in drive and not knowing what did it

[FASTRAKR]

Played with the ultra-gauge this weekend. Looks like if you take your foot off the gas with it in gear it will shut off the injectors. If you do the same put take it out of gear, it continues to spray fuel.

[Shibbs]

Just an FYI - A 0% duty cycle on injectors is still spraying fuel. 0% != 0.

[thehunterooo]

I will solve all MPG issues in seven words....trade in the Aveos and buy Fiestas.....