Chevy and GMC Duramax Diesel Forum banner
  • Hey Everyone! Vote for the Site Favourite ROTM winner for the year of 2021 HERE!
1 - 2 of 2 Posts

·
Administrator
Joined
·
8,815 Posts
I am getting 16 mpg driving around base and to fairbanks a time or 2. My "city" driving really isn't that. Is your speedo recalled for the bigger tires? if not you need to add 7% to the miles traveled. Also, my numbers are hand calculated.
 

·
Administrator
Joined
·
8,815 Posts
you can always buy a handheld programmer and recal your speedo. I know htat 285/75-16 is 7% bigger than the stock tires. Check out this one: http://www.miata.net/garage/tirecalc.html

According to that, if you are running a 305/55-20, your tire is 9% bigger than stock. So, you would add 9% to your miles shown on your odometer and then divide that by the gallons used.
 
1 - 2 of 2 Posts
Top