Am I hurting my tranny?

[gunmunky]

I have a couple of steep hills I drive down each day on my way to work. 2 of my vehicles have manual trannys but one is an automatic. It is a 05 Subaru outback with a non-turbo 2.5 litre. Am I doing any damage to the Subaru if I shift it into neutral to coast down the hill and then shift back into drive while coasting with the speed at 60mph? Thanks for any help.

[DIESELDAN]

I don't think it should hurt but why would you do that anyway? I'm guessing that you think you are saving gas, but the possibility of saving a tiny amount of gas wouldn't be worth the chance of hurting something. Also every man made thing only has a limited number of moves, why put extra ware on something when it really isn't saving you much if anything?

DieselDan

[SkunkedAgain]

From what I understand, the only damage you'll do is by shifting into the wrong gear. You will induce slightly more wear on the transmission but the slight wear is off-set by whatever mileage gain you'll see from shifting into neutral. Most automatic transmissions can coast pretty well down a hill, barely using any gas. So Dieseldan's point is right on, you're really not gaining much if anything but are introducing a higher probability of a transmission problem.

[gunmunky]

Thanks for the input. When I leave it in gear the car will actually slow down with out any gas and in neutral I go from 50 at the top of the the hills to 60- 65 at the bottom. I agree that It's not worth it if I would be causing harm but if not then I would shift to neutral. I'm no car expert but I value the knowlege on this sight more than any other.

Thanks.

[littlebear]

It's also a violation of Minnesota State Statute:

169.39 Coasting

probably difficult to enforce though....

[SkunkedAgain]

That's actually a good point. From a safety standpoint, you may be in a situation where you need to quickly accelerate to avoid an accident.

[Sonicrunch]

That's actually a good point. From a safety standpoint, you may be in a situation where you need to quickly accelerate to avoid an accident.

And the engine adds braking resistance too. And yes, even in an auto, albeit different cars will brake to different degrees.