stock tire size is more than likely 245/75r16 soo 245/25.4X.75X2+15=30.48

 

Same with me

 

So I had stock 245 and then jumped up to 285. So with my math I get roughly 1.16.

With that number I multiply that by the number of miles I get in a tank and then divide by how many gallons I put in. That should then leave me with my new mpg?

It makes sense and makes me alot happier when I figure out my mileage. How accurate is it though?

 

i got 1.08 from a 245/75r16 to a 285/75r16

because 32.84/30.48=1.08

 

How did you get those numbers?

Edit: I see how you got those numbers but how did you figure out the 32.84 vs 30...?

 

edited last post so you could see ^^^^

 

Where did you get these numbers...245/25.4X.75X2+15= (doing that math I get 29 and change)

I just want to know so I can do any truck I want.

 

I have a tuner...I was up to 18+mpg when I was on 33's and 4.10's, not towing, with the eFan and pullies wiht 93 performance tune. I was loving that :) Then the urge to go bigger hit me...and my wallet :)

 

jake, what size rim do you have? i did 15 and you did 16. check that

 

do you understand what all the numbers in that equation mean?

 

Wow I am lucky to hit 200 miles with a 15 gallon tank! lol Of course I drive like **** with the pedal to the metal!!!!

 

Not really. Let me know what they mean.

Thanks

 

ok...245(tire width)/25.4(mm to in)x.75(tire aspect ratio)x2(sidewall height top and bottom+15(rim size)

 

Mike, did you change the revolutions per mile setting?

(I'm about to go with 32s myself)

Rich

 

Yes everything was corrected for the new tires Rich.

 

Justin I got it all figured out now.

2 x 285 x .75 / 25.4 + 16 = Tire Diameter

So is this really accurate when considering your miles per gallon?