So my xA is just about 25K miles on it. And i have yet to do the reccomended 15K mile check up. Im noticing i used to get 35+ MPG and now i can barely get 300 miles per tank. Could this be due to lack of check up and possible low fluid levels, or loose belts? Also my xA is a manual that i drive harder than i should. I also switched from 15's to 18's but i doubt i would loose 10 MPG from it.

 

did you get your transmission oil changed?

 

no. other than oil changes and adding a intake, exhaust, and some 18's, nothing else done.

 

you can loose a lot going from 15-18, heveyer bigger harder to spin. and I think he was asking if you changed your oil like in a regular check up wise, not as in a performance wise.

 

no trans oil changes. Is it something that would affect mileage and can is it easy to flush and fill as a DIY project?

 

its part of the recommendended maintance for your manual transmission. the larger wheels will cause a drop in gas mileage though.