Well I was averaging 23 mpg's with my stock 17' rims and recently installed 19' rims and guess what, my mpg dropped to 17 mpg's. What the heck, I expected to lose maybe 1 or 2 mpg's but not 5. Has anybody else seen a big drop in mpg's as I did. Is this normal.
I can't remember but I think the tires are 245/50/19 but they are stock 2010 wheels/rims. And the car doesn't feel like it accelerates as it should. Anymore thoughts.
Did the wheels and tires feel that much heavier? Hard to imagine it would make that much difference. Check the air pressure. With the shorter stiffer sidewalls maybe it wouldn't look as low on iar even when it is. Try near max rated pressure and see if that helps.
If the diameter is different from factory, it will register miles wrong. Depending on which way it could show you losing mileage even if you really aren't. Are you making the same drives and still adding gas at the same time? If so maybe it isn't off by so much, just saying it is.
Borrow a GPS and compare the speed it says to what your speedo says.
crap, I have a totaly stock 06 GT and only get 24mpg... 25.6mpg with the cruise set at 70mph and driving the entire tank on the highway and I only have the stcok 18's on stock tires! What am I missing??