Size vs weight

[Cupped_up]

‘21 bighorn with Hemi and 3.21 gears…

I need new tires and am trying to decide between sticking with my current size (275/70r18 E-load cooper at3) or sizing up to 295/70r18 nitto recon in a SL-load.

My current 275’s weigh in at 57lbs per tire, and the 295’s in SL-load are only 54lbs per tire.

If I move up in size (~1 inch) but with a slightly lighter tire, should I see an increase, decrease, or about the same in my MPG?

And no, I don’t drive my hemi for gas mileage, but it is something I am factoring in to my decision.

 

[Trooper4]

The circumference of the tire will cost you more than the weight savings will gain.
But hey, whatever makes you feel good.

 

[Jupiter58]

Shouldn’t notice much of a difference, but you are going wider and taller. The -3 pounds will offset some of the difference.
And yes weight matters. Not 3 pounds so much but when you get to 10 a wheel now it’s noticeable.
I got rid of the po’s steel wheels and heavy 32’s on my jkur and went back to stock wheels and a lighter 33. Saved almost 15 pounds a wheel/tire.
That was significantly noticeable with the 3.6 motor and even braking improved tremendously.

 

[CHeYeNNe71]

Yeah going wider adds more resistance which would probably offset the weight savings. Just go with what you want and not worry about any difference.

 

[CalvinC]

That’s the size leap I made on my truck a good while back and I noticed no statistical or observable change in mpg, and I track every fuel up in Fuelly, and recalibrate my speedo for each tire size dead nuts accurate with GPS.

The 275’s were DuraTracs (aggressive tread) and the 295s were Bridgestone Revo3’s (mild tread for an AT).

Both Load Range E, but the 295s were actually 2 lbs lighter than the 275’s.

All that to say, your mileage will literally vary by so many factors - diameter, weight, width, tread design and compound. You balance all these factors and the MPG hit may not be bad.

Alternatively, you go crazy in just one of these areas MPGs will go south.

 

[1923bob]

I have the 3.21 didn't change much.

 

[Trooper4]

Although it might not be much of a differences, tire contact patch also is an added cost to mpg.