Driving technique. Is NICE bad for transmission?

[Mohammad Abdullah]

On my automatic 11 Camry or any gas car I've been using the following technique to minimize gas use:

DWL for hills
Turn off at stoplights once engine is warm
Shift into neutral approaching a stop and at the stop (stress on drivetrain from keeping it in D while holding brakes?)
Downshift while braking using sport mode (keeping rpm under 3k)
Shift into neutral and engine off for long coast on empty street

I just learned the transmission pump is driven off the torque converter so putting the car in neutral, ICE on or off, means no fluid or lubrication while neutral coasting. If I understand correctly, this is damaging to the transmission. I see NICE on recommend often, can anyone explain? Thanks

[MetroMPG]

Welcome to the forum!


Another automatic transmission efficiency technique: if you have "sport mode" (ie. gated shifter or paddles/buttons), you can often get the transmission to upshift sooner and get into top gear earlier than the default transmission programming. This works even with CVT's - see "Short-shifting" a Jeep Patriot & Audi A4 CVT (forcing early "upshift") saves gas


As for your question about potential damage while coasting in neutral while idling, it probably depends on the individual vehicle. I spoke to a mechanic at a transmission shop specifically to ask his advice about the same questions you posted and his only warning was to avoid engine-off coasting in N, but he may have been generalizing to most vehicles. I'm not sure.



There are some transmission designs where it might be an issue. Just as there are some auto transmissions where you can safely coast in N with the engine off, eg: https://www.etrailer.com/question-142325.html


Best advice is to know the details of the car in question.

[ksa8907]

Nearly all transmissions will pump as well as circulate fluid when the engine is running and in neutral. Engine off is much more uncommon.

[Piotrsko]

See if it is a common RV support vehicle, if it tows then it has some sort of fluid circulation engine off.

[Mohammad Abdullah]

Thanks for the welcome and the advice. I found this website that seems to be the official Toyota site. Toyota.custhelp.c000m/app/answers/detail/a_id/7710/~/is-it-possible-to-tow-my-toyota-with-all-four-wheels-on-the-ground%3F]Is it possible to tow my Toyota with all four wheels on the ground? which shows an automatic camry cannot be towed on four wheels. I've done this for a total of about 30 miles, maybe less. The engine and transmission were warm and hopefully well-lubricated so I didn't do any real damage.

I guess I should also stop doing neutral as I roll into a stoplight

[19bonestock88]

Neutral while coasting with engine running should be fine

[Stubby79]

Converter and pump are still running/rotating with the engine on in neutral; it's just the gears that go in to neutral. The output is turned off, not the input.

[Piotrsko]

Generally you get 50 miles going less than 55, or about an hour before damage occurs, which is bearing wear to the output side unless it was in park.

[mpg_numbers_guy]

Of the several thousand miles I put on my automatic Civic before selling it, I probably traveled hundreds of miles in neutral with the engine on. Transmission shifts just as perfect as it did the day I bought it. As long as the engine is on you'll be fine. Heck, I even turned off the engine and coasted the last 20 or so feet, and was fine. Longer distance EOC in an automatic is what ruins the transmission, as well as neglecting to regularly change the transmission fluid on schedule.

[Mohammad Abdullah]

I did NICEoff for only a few minutes each time but twice on a hill, I must have reached 75 mph and 4 miles all other times were about 35mph for a flat mile. Now I'm aware, the miniscule mpg benefit of NICEoff probably isn't worth the potential $100s repair.

For NICE on, is the mpg savings actually significant? I believe idle rpm is like 1 US gallon per hour + don't have to hit the gas at the bottom of the hill VS engine braking using zero gas + accelerator at bottom of the hill. Are there any conclusive results? Thanks everybody