Better Gas Mileage? You're Kidding

[kinchy]

I finally take off the stock Grandtreks and replace them with Toyo Proxes (275/60/17). The Proxes are summer performance shoes.
I figure given the additional width of these tires they will create more roll resistance. With the stock Treks I could never squeeze more than 16.1 mpg around town and 20-21 on the highway.

Believe it or not my around town (no AC) went up to 17.4 mpg and after 45 miles on the highway yesterday in traffic, with AC I got 21.3 mpg. Go figure?

Could it be the new tire size is screwing up the MPG computer? Hey I'm happy but I'm fishing for a reason...

W

 

[RonMAIDEN]

You need to not go by the computer since their accuracy can easily be in question;the real way to tell is do the fillup and calculate your mileage and keep track for more than just a few tanks.

 

[Kmvreter]

I went up a size with the Michelin CT's and have the same. I'm keeping track of fillups and figuring in the % increase in different (actual) mileage.

 

[Falls]

I believe the comp. to relatively accurate . Its meant to give averages. I've tested mine with a avg. mph and it reads right on , I also ran a test to check my milage ( the old fashioned way ) and got 18.2 city. and the comp read an average of 17. something.

Close enough for me , but like I said its meant for averages , like it even says on the display.

So if you want to check accurately you need to do it the old fashioned way with gallons used and miles traveled. You will also need to compensate for the tire change size , if your looking for dead nuts on .