2020 F-250 with the 7.3 10 speed. IF people actually are getting the mileage they say they are, I'm getting less than most. The inside of my tail pipe is black...sooty. In the old days that was a sign of a very rich running engine. I have noticed several other 7.3's with sooty pipes. Also transmission in tow mode with 5th wheel trailer descending steep hills holds me back nicely. Particular gear of coarse depends on speed. When I reach bottom of hill say in 5th gear, whatever gear it chose to hold me back as I step on it to proceed it sometimes takes a long time to shift back to normal gear. Sometimes on the level if I proceed at say 60 mph it remains in 4th-5th gear turning 4,000 + RPM for a considerable distance before it finally shifts. Bought the truck new and it never did this before. ...of coarse when my uncles horse died he never had before either!!
When I left it off they said there was a reset order on the transmission, not the recall that is out on some made in a certain plant but a service bulletin. Just called they said no codes on transmission and that some of the 10 speeds did that in tow mode some times! I told them it didn't do it the first 15,000 miles or so and they basically said "it does it now"!! Also no codes on the engine tune, air filter is clean. I asked "so the pipe is supposed to be black and sooty?" He said "evidently"!! I nicely said "well its on record it isn't acting right and the service writer said he agreed"!! I'm glad I bought the extended warranty!!
I have bragged about my dealer but I'm starting too think there is no such thing as mechanics today but instead code readers!!!