Here's an updated mileage graph for our 35d. The black diamonds are MPG (US gal) calculated from the miles and gals since the previous tankful. Note the low MPG tanks (except the first two) are when we were towing a trailer.
The lifetime mpg on our 35d is still not above 22 mpg. I'm not complaining. In fact, I'm pretty happy given the towing etc.. We still see 50-100mi runs between 27-30mpg. But these are not a very good indication of real world overall mileage unless you do a lot of long distance highway driving.
On a side note: The last tankful included a 100mi round trip run into the city. When we got there, the OBC was reading nearly 30mpg. And it was still reading 26.2 mpg when we started home after a bunch of stops for shopping etc. Still not too bad. But we got caught in stop and go traffic. We were literally crawling for well over 30 min.. I expected the mpg to drop like a stone. But it didn't drop a single .1 mpg
In fact, it was still reading 26.2mpg when we got home 40 miles later.
FWIW I'm not sure why the 30+ min. stop & go segment didn't hurt the mpg. But it could be because I was consciously keeping the revs down; hence keeping the turbos from spinning up. BTW this was not difficult since we were crawling anyway.
Funf Dreisig