Engine Brake when cruising downhill (does it use more fuel in B?)

[Maou]

Does it consumes more gas? while crusing downhill, and on B (engine break), RPM is really high (especially when moving downhill faster).

some mirage owner friends had an impression that the RPM directly means more gas. but i'm not sure if this is
the case when not stepping on gas pedal.

[Canoehead]

Does it consumes more gas? while crusing downhill, and on B (engine break), RPM is really high (especially when moving downhill faster).

some mirage owner friends had an impression that the RPM directly means more gas. but i'm not sure if this is
the case when not stepping on gas pedal.

I will venture that no, it does not use more gas for going down the hill. If you take into account that you will be losing speed compared to coasting in neutral it would, since coasting in neutral the speed gained could help climb the next hill. Put another way, if going though a series of hills/valleys with no stops and no speed limit, I would coast down the hills and part of the way up the next hill. If I had to stop at the bottom of each hill, I would leave the vehicle in gear for going down hills.

[MetroMPG]

It depends on whether the engine is in "deceleration fuel cut-off" mode (DFCO) or not.

FYI, anginlumpur and polkiuj were talking about that in this thread: http://mirageforum.com/forum/showthr...r-Filter/page2

pokiuj said:

I rarely use B but the times I did, it went into DFCO almost instantly. Will need to test more to confirm.

http://mirageforum.com/forum/showthr...ull=1#post2518

My guess is you likely aren't burning any fuel above about ~1500 RPM when you release the accelerator in D or B.