Interesting, I checked mine and after 6,451 miles using the math I got 35.15 mpg and the computer thought I got 35.4 which is remarkably close to the actual number.

I have heard that the computer can be significantly off and was pleasantly surprised that it was so close to the actual figure.

39.5 mpg was the highest mpg tank on the trip 33.2 was the lowest.

__________________
1999 Mercedes E300TD daily driver sold at 238K miles 106K miles were mine, rust worm got it :-(
2006 Mercedes CDI new daily driver! 56,000 miles May 2016 now 85,625 Apr 2018 and Apr 2019 101,000 miles Apr 2020 109,875. March 2024 135,250, Dec 2024 145,000 miles