Today I drove my 2005 Acura RL for about 90 minutes on an interstate (on cruise control). Out of curiosity, I reset the trip computer at the start when on interstate. My miles per gallon remained at 29.6 throughout the interstate driving after 10 minutes or so. Attached is the screenshot after 32 minutes. Trip A was reset few minutes before hitting the interstate whereas trip B is totally interstate driving. Just wondering if it is normal?

Thanks a bunch.

 

yes, look and analyze the data....
you drove at an average speed of 71 miles per hour for 32 minutes....

 

This looks totally normal. But not indicative of realistic "normal" driving. Once you add in some stop 'n go and city driving, it'll get down to the normal range of 18-22.

 

These past 9 months I've been resetting Trip A at after each fill up, while allowing Trip B to average out over the past several months. Typically after each fill up, Trip A shows 30 to 32 MPG for the first quarter tank. It then drops to 26 to 28 MPG by the time I'm ready to fill up. Trip B tends to drift between 26 and 27 MPG consistently.

My cars fuel consumption data tends to read a bit a high. When I divide the miles travelled by the number of gallons to fill up the tank, I usually get 24 to 25 MPG.

 

It just depends on your mix of highway vs. city driving. Anything with stop and go kills the MPG for the RL. I do mostly city driving these days and my MPG never gets above 19, and that's with me driving it very gently.

 

I can get 27 by setting the cruise to 75 mph, and probably a bit more if I set it slower, but in town in the winter I've logged as little as 14 mpg. As I've said before, the only way I'd consistently get 20+ is to either drop the car out of an airplane or, as C/D's Bruce McCall once joked about how old British cars could meet modern emission standards, by carrying it on the back of a flatbed truck that met them. 4,100 pounds + SH-AWD + 290 hp is just not designed for fuel economy first.