Does this do the tranny any good Or BAD?

It seems to be logically it's good, because the tranny sitting at N rather then D and holding down the brakes

Then again it seems to hurt the tranny because of the more often transition from N to D and D to N.

Which one would end up being better?

 

it doesnt really matter, AT was designed with stop in mind.

I think it actually burn more gas in N than in D with Brakes on.

Just leave it in D.

 

Actually, putting the car in N while stopping at red lights saves gas. If you know the light just turned red, it wouldn't hurt putting it in neutral. And nothing will happen to the tranny either..

 

Nothing will happen of course. but I think for a Rotary it uses more gas to idle than to run.

 

unfortunately your correct - nature of the beast.

 

if you just drive around town for 15 minutes, your gas needle probably will not move much

but if you sit and idle for 15 minutes ... you will cry.

 

No
In D you are putting a small load on the motor which will not only use more gas but put more heat into the engine/transmission - this could cause overheating in extreme conditions (ie hot day with less than perfect radiator etc )

 

no no no

think about it nycgps - at idle afr sits at around 14:1 . At cruise AFR is around 14:1 also . The difference is 800rpm vs 3000rpm - you HAVE to be using more gas when the motor is at a higher speed .

 

haha......Couldn't help but laugh on that one. I think I learned the hard way.

 

no need to no no no

try it, you'll know what i mean. keep it slow and hmm less than 3 K rpm tho. it will use more or less the same amount of gas (assume that your engine already warm up and ready to go)

 

Does the RPM change in N versus D at stop/idle? If yes, then the one with higher RPM might burn more gas. But the one with higher RPM will keep engine cooler too (because the water pump will run faster) and will reduce idle shaking as well. So do the test and draw your own conclusions...

 

Lol..I have no idea, guess i'l leave this at D, it's for my mazda3 anyways=P

 

Absolutely correct, ever since somewhere back in the sixties when they removed the rear pump from the auto tranny, of course this also negated push starting a car with an auto transmission. AHHH for the good old days as kids driving junkers, we could push start anything. lol

 

who said anything about coasting ?