Is shifting into neutral to save gas on my (automatic) transmission bad for the transmission?

Question

To save gas, I shift into neutral on downhills and coast for as long as I can. Because the engine has lower RPM's while in neutral, I use less gas. However, I've been told that this is bad for the transmission. Is it?

If yes, does the gas money I save make up for the cost of damage to the transmission in the long run?

Answer 1

Not only is it bad for the transmission it is also dangerous. Stop doing that!

Answer 2

for an auto tranny yes its bad it just adds more stress to your engine if your car was stick then it would have been OK

Answer 3

the small amount of gas you will save pales when compared to the price of a tranny.

Answer 4

It is not bad on your transmission, the reason towing a car is bad on a transmission is because your engine is not running while being towed thus the trans coolant lines are not working. But I've heard a lot of talk about "hipermilling" where they actually turn the engine off, this is extreamly bad idea, first the extra work of the starter at every red light.

second when you shut the engine off you loose the power steering and your power brakes. Hope this helps.

Answer 5

yes, it will mess up the transmissin... and will not save that much gas. you will end up spending even more gas when you go to accelerate when going back to drive

Answer 6

You might be able to do that in a manual transmission but i would not do that in a vehicle with an automatic transmission as they are a lot more sensitive and that will put alot of stress on the transmission. You really arent saving any gas money because when you have to put it back into drive you will have to accelerate and that will use more gas than keeping a steady speed in drive. Gas engines waste the most fuel when starting an accelerating.

Answer 7

i dont think it will damage it if you dont accelerate first then drop it in at a high rpm ave trans fix 1500 to 2000 dollars

Answer 8

>>  I've been told that this is bad for the transmission. Is it?

Yes.  It is like getting your car towed.  And that is bad for the tranny.

>>  If yes, does the gas money I save make up for the cost of damage to the transmission in the long run?

That is hard to say.  My Audi tranny is a small fortune.  My Civic tranny is relatively cheap.

Good Luck...

Answer 9

It doesn't harm your transmission but your theory is absolutely faulty - your technique actually burns more gas.

Think about it.

What happens when your transmission is in gear and you lift your foot off the throttle?  The transmission keeps the engine revs up so the engine doesn't stall, and since your foot is off the gas pedal the injectors are closed - your not burning any gas.

What happens if you shift into nuetral?  The engine revs drop to idle so one of two things has to happen. 1.  The engine will stall or 2. the PCM will automatically open the injectors and start dumping fuel to keep the engine running.  Thus, shifting into neutral while coasting actually uses more fuel, not less.

Not to mention the safety factor of being in a moving vehicle with the drivetrain disconnected.  That's just dumb.

Even if it did save you some gas mileage it would be pennies.  A new transmission costs $3,000 and up.  

Answer 10

The tranny doesn't care.  However, It is really dangerous to drive (on a hill, etc) in neutral.  Without knowing it, you actually use your engine and tranny to help you slow during normal driving.  You COULD get into a position where you need the engine power IMMEDIATELY and not have it.  Please think it over.  //you won't save squat on gasoline doing it, either//