Expert: Kevin Pilotte - 3/22/2006

Question
Kevin, I drive an automatic and sometimes, on gentle slopes, let the car just roll in neutral before I kick it into "drive" -- is it ok for me to do this? I have always wondered whether controlling the vehicle with brakes alone, propelled by the power of gravity, does any more or less damage to the discs than if it were in gear.

When travelling downhill in an automatic,  you controll the speed with the brakes anyway, so what's the difference?

I'm glad we have forums like this to ask questions, because I'd probably be too embarrassed to ask otherwise -- forgive my naivety!

look forward to your (chastising?) reply;-)

sincerely,
Mike.


I occassionally let a car roll on a gentle

Answer
No chastising, I'm not Click & Clack on NPR.
Technically speaking, placing the automatic transmission in neutral when braking won't cause severe damage, as long as the engine is running and the vehicle isn't traveling very fast.
The question I have is "why are you doing this?"
When you release the accelerator pedal and coast with an automatic, the trans usually free wheels. Some newer trans will actually downshift on deceleration and when braking, assisting in slowing the vehicle.
There is really no benefit to placing the trans in neutral so I would suggest not bothering with what you're doing and leave it in gear.
Or buy a manual transmission vehicle!
Kevin