driving in neutral to save fuel

hothothot_3

I ask because I was in a mates car which is automatic transmission and I asked him why he slipped it into N whilst going down the hill and he said to save fuel. is this good moneysaving and would it work in a manual gear car too?

custardy

IIRC its not moneysaving as the ECU eases back on the fuel on overrun
whereas taking it out of gear makes it idle
however on a safety note its far safer to have the car in gear and driving rather than coasting in neutral

DUTR

hothothot wrote: »

I ask because I was in a mates car which is automatic transmission and I asked him why he slipped it into N whilst going down the hill and he said to save fuel. is this good moneysaving and would it work in a manual gear car too?

Not only is that the height of tight, it maybe deemed as not being in full control of the vehicle, if it is a modern car with fuel injection, I'm pretty sure the fuel is next to shut off on deceleration.

waynedance

in a word NO..........

Pew_Pew_Pew_Lasers!

Your friend is misguided. He isn't in full control of the vehicle, the engine is using fuel where it otherwise wouldn't, and he is also increasing wear on the gearbox by removing it from D to N unnecessarily. Reconned gearboxes are about £1,000.

WEEGIE

Not a good idea as has been said before. You have virtually no control of the vehicle [EMAIL="'driving@in"]'driving' in[/EMAIL] neutral.

michaelvintner

Why not turn the engine off when going down hills. In fact better still don't buy petrol and push the car everywhere :rotfl:

computershack

On overrun, i.e when going downhill and the engine isn't providing drive, if you leave it in gear the engine management cuts all fuel to the engine so it doesn't use any. By taking it out of gear, it is idling and therefore using more fuel.

BUT AS IT IS AN AUTOMATIC, putting it in neutral will completely shag the gearbox, blowing the valves and servos. If he looks in the owners manual, it'll say how to tow the vehicle and for an automatic with the driven wheels on the ground, that means a very short distance (usually around 1km) at usually under 10MPH. What he's doing is basically the equivalent of towing it at whatever speed he happens to be doing.

tsstss7

its illegal - hes not in full control of the car. I doubt it saves much cash either!!

waynedance

I look forward to post about obtaining a recon auto box!!!

blue_haddock

There is a technical name for what he is doing.

Scotch overdrive!