T-dot B6

i heard downshifting is more fuel efficient than braking...is this true? if so how? TIA

Aman_UnatrlyAspiratd

fuel is burnt to release energy. Brakes convert a moving vehicles kinetic energy to heat, via friction.

travelling distance 'x' using brakes as opposed to downshifting will release (waste) kinetic energy as heat, whereas downshifting would not, therefore braking must be less fuel efficient.

my guess! Honestly, i'll bet real world results would differ....(eg. lost energy with clutch engagement, burnt gas with rev matching, etc)

afretes

Hey, no foreign languages please. English only.

afretes

and this to me equals to burning fuel. So I use the brakes.

Jet Jockey/A4 Pilot

Gas you are simply using the engine's compression in helping you to slow down. You are not saving gas but you are not consuming any either. The real advantage is saving the brakes and perhaps by having the engine at a higher RPM; it is ready for an immediate output of power instead of being at idle.

afretes

I never saw it this way, it makes sense though.

akula-ssh

Well, downshifting causes rpm to go up, which is also bleading energy as heat

akula-ssh

If the engine's in neutral when one brakes, the engine idles, and thus requires fuel. On the other hand, forcing the engine to go at higher rpm while downshifting doesn't use any fuel at all...

1.8TQ99.5

Any way you cut it, higher RPM = more burnt fuel, and higher engine temps. Braking is generally done under low RPMs.

Also, using the engine to stop the car not only puts a load on the engine but also stresses the transmission.

By contrast, the brakes are designed to stop the car, and are cheaper to maintain and fix than the engine and tranny.

1.8TQ99.5

where do you thinkg that energy is going? unless you're driving a hybrid and recapturing it, that kinetic energy is released either through friction (brakes), or into your engine and tranny.