Can't decide if i should go up on tire size

[Chris1911]

I have been running the stock tire size 275/70/18. I would like to go to 285/75/18 (35"), but not sure if i should. I don't want to lose much mpg, mainly when towing, and not sure how the gearing change will affect the towing performance.

What experience do you guys have with running larger tires, as far as mpg and towing goes? I have the 6.4 with 3.73 gears and tow a 32'/7200 lb travel trailer occasionally throughout the year.

 

[406Linetrash]

I have 4.10's. But I don't think it will affect anything very much. Might lose 1 or 2 mpg.

 

[Chris.Gio]

I have been running the stock tire size 275/70/18. I would like to go to 285/75/18 (35"), but not sure if i should. I don't want to lose much mpg, mainly when towing, and not sure how the gearing change will affect the towing performance.

What experience do you guys have with running larger tires, as far as mpg and towing goes? I have the 6.4 with 3.73 gears and tow a 32'/7200 lb travel trailer occasionally throughout the year.

Getting these when truck comes. Go for it!

 

[Rockcrawlindude]

Getting these when truck comes. Go for it!View attachment 14755

Those are 33.5” which is about the same size as stock.

285/75-18 are 35.4” which is ~6% larger than stock

There are dozens of threads about going to 35” tires.

Yes you can do it.

Yes you will lose a little mpg.

 

[Chris1911]

If i get them, i'm going with the Cooper Discoverer AT3 XLTs.

 

[Chris1911]

Those are 33.5” which is about the same size as stock.

285/75-18 are 35.4” which is ~6% larger than stock

There are dozens of threads about going to 35” tires.

Yes you can do it.

Yes you will lose a little mpg.

Nothing comes up in a search. Found a few by manually scrolling through the threads.

 

[parsonj]

285/75-18 are 35.4” which is ~6% larger than stock

You'll also be going about 6% faster than speedometer speed without re-calibrating. Your fuel efficiency drop will also look worse than actual without re-calibrating (still a drop as others have said). I know Jeep's can be re-calibrated pretty easy--at a cost. Not sure about RAM's.

 

[Rockcrawlindude]

You'll also be going about 6% faster than speedometer speed without re-calibrating. Your fuel efficiency drop will also look worse than actual without re-calibrating (still a drop as others have said). I know Jeep's can be re-calibrated pretty easy--at a cost. Not sure about RAM's.

Yessir. Plenty of threads on that as well.

 

[bfs673]

I did this on my '14 3500 SRW with 3.42 rear end. The towing performance beforehand was ok. Going to the larger tires, although it would still tow, really reduced the performance climbing the passes in eastern Oregon.
So bad I actually took the tires back and went with stock size. My rig was ~15k lbs

Now, with the 3.73, going to the 35" tires would put it pretty close the the 3.42 performance. Depending on your tow weight, you will likely feel the difference in towing.
I didn't have them on long enough to comment about the MPG difference.

 

[Chris1911]

Now, with the 3.73, going to the 35" tires would put it pretty close the the 3.42 performance. Depending on your tow weight, you will likely feel the difference in towing.
I didn't have them on long enough to comment about the MPG difference.

The calculator on tiresize.com says the new effective gear ratio will be 3.61

 

[Rockcrawlindude]

I have no regrets. It’s a hardly noticeable tire size change in my opinion. Under 10% really who cares?

been running mine for over a year, over 10,000 miles. Towing 6500lb as often as I can get away.

Im a re-gear snob (Toyota w/ 5.29s and have 5.13s sitting on the shelf for my Jeep) but those rigs have much greater than 6% larger tires on them.

The 8 speed behind the 6.4 is great, it has great gear ratios and the engine has plenty of power.

 

[Chris1911]

Decided to go for it. The ride seems to be a little better. The mpg doesn't seem much different so far, but need to hand calculate and would also like to the get mph calibrated. Love the looks.

 

[Rockcrawlindude]

Decided to go for it. The ride seems to be a little better. The mpg doesn't seem much different so far, but need to hand calculate and would also like to the get mph calibrated. Love the looks.

Looks great and gorgeous color truck

 

[MEGA HO]

Looks great and gorgeous color truck

Oh come on, it's blue!!!

 

[Rockcrawlindude]

Oh come on, it's blue!!!

Mmmmm blue

 

[wjcook68]

I will second the comment on great color! I named mine Big Blue 392 or just Big Blue for short. It's a CCLB.

 

[Chris1911]

I always get comments on the color. I don't think i have ever seen another 2500/3500 around in this color.

 

[AFF]

Mmmmm Blue

 

[wjcook68]

Seriously bad-ass looking ride you have there.

 

[MEGA HO]

Actually nice color, I wish I had HD RAM of every color in my garage.