got a tricky mpg question

[chvymudin3388]

now think about this, lots people say oh you lose mpg with bigger tires. well when u put big tires on it throws the speedometer off so it also throws the odometer off and shows u going less miles than u actually are on the tank of gas but this also depends ont e engines power band im just a lil curious on te whole deal

 

[tRustyK5]

Bigger tire = more rolling resistance...less mpg. Even figuring in the speedo error you'll still often see a drop in mileage.

Rene

 

[chvymudin3388]

but like with gearing correction and all i mean its possible right i mean i am by no means saying throwing 44 will give u better mpg im talking round 35 and around that

 

[cbbr]

I went from stock to 35's with my 4.11s and didn't see a drop. Of course it could not possibly get much worse....

 

[redneckdude]

i saw no drop going from 33s with 3.08s to 40s with 5.13s. My motor is MUCH happier. It is possible, but a rare occasion, to have it stay the same or gain a bit (which it actually did in my case, and yes the speedo is dead on).

 

[Masiony]

Bigger tire = more rolling resistance...less mpg. Even figuring in the speedo error you'll still often see a drop in mileage.

Rene

yes, more rolling resistance, more weight, more everything. here is one to consider, you are also higher therefore more wind resistance.

 

[4xcrazy]

Lifted 4", went from stock 31's to 35's, 3.42 gears to 4.11's and my MPG has definately dropped.

I know this by the several trips to the SoCal area i used to take with it.

Interesting too, the '78 Caddy i am driving to work now, has a 425BB, and gets quite abit better mileage than the Burb does

 

[tRustyK5]

yes, more rolling resistance, more weight, more everything. here is one to consider, you are also higher therefore more wind resistance.

Yeah, higher doesn't help mileage any either...

Rene

 

[duanel]

but wouldn't going to a taller tire be similar to going to a numerical higher gear ratio much like a overdrive. while yes you would have more weight and rolling resistance (depending on width) and less accellaration shouldn't you get slightly more mpg if the engine could handle the tires without changing the gear ratios of the diffs(everybody else is mentioning a gear ratio change along with the tire chang).

 

[blazinzuk]

stock with 31s 10mpg stock with 35s 10mpg 10" lift 4.10s 38s 10mpg 40s 4.56 and one ton running gear 8mpg unless I slow down to 60 then I get 10 mpg

 

[divorced]

To accomplish work (making tires turn) you need energy (fuel). If it is more work to turn larger tires, it will use more energy. Nothing is free.

 

[Masiony]

in a perfect world, all this "on paper" stuff would translate to actual results. but in our world we have a little thing called "friction". it is going against us trying to get geo mpg with our full size pigs.