Have you checked the fuel mileage stated on the trip computer versus actual mileage?
I expected some optimism, but it varies considerably. Tonight's check for
271 miles of mostly highway showed a difference of 0.9 mpg. Computer stated 29.2 but calculated was 28.3 mpg Last week the difference was 3 mpg. others were in the 2 mpg range of differential.I'm not sure what should be expected on that type of metering, nor do I know how the fuel consumption is measured. Is there a flow meter of sorts?