Originally Posted by RememberMeJoeB
2012 prem MT. Im so disappointed when the car gauge says 28.5 mpg at 35 average mph but when calculated at the pump it is ALWAYS 2.5 mpg less so 26.1ish . You are lucky to get 29mpg at 80-85 cruising.
I never understood how rolling in neutral at 25 mph gets 99.9 mpg and rolling at 55 also gets 99.9mpg.
The computer is saying 99.9 mpg indicating no fuel consumption while rolling in neutral, it does not matter what the speed is.
However, you are using fuel while rolling in neutral, to maintain engine idle.
Keep the car in gear, rolling in gear (for example, down a long hill) does not require fuel to flow through the injectors.