MPG Tire Size Comparison

That is awesome. I figured someone somewhere made a speed sensor calibrated for bigger tires. I'll definitely purchase one when I get my tires.

 

Yes, stock Pro 16" rims.

 

I wonder how much of a difference there is between yours and mine regarding gearing and power.

 

Hmm, that would be some interesting math. First I would compare power and weight, though. 3rd gen is 278 HP and 265 lb-ft torque (compared to 190/220 for a '99 V6). But the 3rd gen is significantly heavier, '18 is 4480 curb weight, compared to 3280 for a '99. So HP and torque to weight ratios are actually pretty close -- slightly better HP to weight for the 3rd gen (7% better), slightly better torque to weight on the '99 (12% better) which is usually better for a truck, especially for larger tires.

Rear end on the '18 AT is 3.909. Gear ratios are:

1st 3.6
2nd 2.09
3rd 1.49
4th 1
5th 0.69
6th 0.58

Just not sure this makes any difference -- I think there's a point where regearing just becomes a better option when going with bigger tires, not just for MPG but driveability.

 

Interesting that the 1st gen has a higher torque to weight ration.

Rear end in the (my) '99 MT is 4.10. Gear ratios are:
1st 3.83
2nd 2.062
3rd 1.436
4th 1.00
5th 0.838

So re-gearing is probably only worth the cost with 35"+ tires.

 

I'm getting about 18mpg with 255/85R16 BFG KM2's and 4.88 gears (2.7l w/5spd)

 

That's not bad at all.

 

I hate you guys

 

If you are looking for better gas mileage I know someone who would take that pesky Supercharger off your hands. I'm close by too

 

I am running 33s. Recently started tracking my MPGs and am getting around 17mpg. I rarely go over 60mph since I just go to and from work. That being said, the truck is also empty...nothing in the bed or cab other than myself.

'99 Ex. Cab, 4x4, 3.4, Manual Trans
33x12.5x15 General Grabber ATs / 15x10 Procomp 252s

I also just got a set of SCS SR8s that I am going to wrap in 255/75 BFG muds, so I will keep you posted on what that does to my mileage.

 

Cool! So only a few less MPG's. I can live with that.

 

Holy poop! I went to 31.9's after my wee lift and have been calculating my mpg the same way I did b4, with the odomenter difference between fillups divided by the amount filled at the time.. How the heck do I correct for the new tire size. Uuuugh Math!?!

 

I did the math up there somewhere