I was wondering if any of you guys out there have upgraded to the taller 70 series tire from the 65 series. I was wondering if by going to a taller tiresize if it affected anyones MPG. I have a Hemi AWD with 3.92 gear ratio. The taller tires will bring the ratio to something in the 3.7's gear ratio. Te tires, even though they are both 265's are different in width. On the goodyear site the 65 series is 10.2 wide and the 70 series is 10.7 wide. The height on the 70 series is about 1" taller.
Has anyone gained or lost MPG with this setup. And if how much?
Thanks.

 

Heres a site that compares one set of tires to another and tells the differences in size and speed changes. http://www.discounttire.com/dtcs/infoTireMath.dos

 

I had 265/70/R17 Michelin Cross Terrains put on my Hemi Durango when it was pulled off the truck at the dealership. I don't know what it would get with the smaller tires on but I get 17.4 or so for all my driving. We live in the country so say 60% highway 40% city. Thats milage is from the overhead display so figure 18 after correcting for tire size. I will say the extra 1" of OD fills out the wheel wells alot better. And if you can afford it, go with the Cross Terrains, they are head a shoulders above anything Goodyear makes.

 

Just a note: AWD vehicles requires all tires to be the same circunference to avoid damage to the Diff's while they're in move. Remember to change also your spare tire just in case. Maybe you already know this but I posted because no one mentioned it.

Wider tires (if you're moving from the 245 to the 265, that would be my case) will create more resistant on long highway driving. In the other hand, if you were originally with the 265-65-17, and plan to move to the 265-70-17, then your MPG will not change to the bad side. I saw one with this tire size and it balance the whole view (tire + body)

Regards,

 

I've been running 265/70/17 BFG All Terrain TA's on my Limited Hemi for about a year, and I get about 17-19 highway with these tires, averaging 70-75 mph. This wasn't much difference than with the stock tires. I did, however, calculate by time/speed/distance that my speedo is more accurate with these.