Bob & Sue
Active Member
I have actually noticed this on all three of the cars. The difference now is we drive the truck and the convertable more then in the winter. I feel like a 100 mi difference is extreme. Seperate cars and sep odometer so I would not think they both went south at the same time. Just did a tune up on the truck and replaced the air filter in the car last fall(we don't drive it in the winter). Don't know why my mileage has gone to crap? Can't blame it on different octains either. Have tried the lot with little difference...
If you've done all that something is wrong I'd at least take one of them in for a diagnostic test if they find something wrong it'll pay for it with the fuel savings 100 miles loss on a tank is extreme. You might even try a shop that has a portable analyzer to run plugged in for a couple days to get a better idea of whats going on.