If I can return to the OP.
Quote:
Originally Posted by Atheria
Since then, I've been extra diligent about throwing the car into neutral and coasting as much as possible, etc. I was expecting to get 50 mpg on this fill-up, but nooooo....I averaged only 38.2 mpg! How can that be?! I've done the same percentage of highway vs. city driving I think, or at least approximately. I've not been gunning the car or anything. I can't figure it out and am really upset.
Atheria
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I think that this is something that has been overlooked or not explained adequately:
"I've been extra diligent about throwing the car into neutral and coasting."
If you are coasting in neutral the engine is idling and consuming fuel. If you are coasting in gear sometimes it will not be.
The key is that while most of the time the engine will be driving the car, under some circumstances, such as when decelerating or coasting downhill, the car is capable of driving the engine. Under such circumstances the computer that controls the fuel flow to the engine may shut the fuel off.
Just as the engine is not capable of driving the car without a gear selected and the clutch engaged, the car cannot drive the engine without a gear selected and the clutch engaged.
Exactly when the fuel shut off occurs depends on what has been programmed into the computer but it is likely that it will only occur with the car at operating temperature, engine rpm above about 1500, and zero gas pedal. It will resume supplying fuel at a slightly lower rpm or anytime the gas pedal is depressed.
There is an easy way to tell when the shut off is occurring: look at the instantaneous consumption reading (additional stress not withstanding) and when you see "- -", the fuel cut off is active. You can adjust your driving to maximise the cut off time. You can start by leaving the car in gear!
Quote:
Originally Posted by Atheria
It'll probably tell me I'm putting the car in neutral too much. 
Atheria....vroom vroom! |
Probably
.