Quote Originally Posted by dn3187 View Post
my 2011 Aveo with 5sp manual trans and 48,000 miles would routinely get 36-38+ mpg. After replacing original tires with one size larger (195's - Michelin) my mielage has dropped to 32-33. My speedometer is also off by 2-3 mph. All driving conditions have remained the same (commute 75 miles daily hwy travel).
Only thing I need to check / replace may be the air filter.

Do you guys think this decrease in mileage is due to tires only or something else going on?
What you may not realize is that it not only affects your speedometer, it also affects your odometer. It also could be due to the design of that particular tire. Also, it may be colder weather than usual in your location.

It could even be all of the above.