dbok

I am looking at the Nitto Trail Grapplers.

I have a 2011 EB 4x4 Max Tow and 3.73 gears. I ordered it that way because I intended on putting bigger tires on it. I want to go with the biggest of the 3 tire sizes below but I am afraid it will change my final gear ration to much. After researching this site, most have said they have no rubbing issues so I am not concerned there. I tow about a 6,000 lb boat. I live in the northeast and tow in the mountains. Any thoughts on whether or not the bigger tire size will adversely affect my final gear ration or am I way overthinking it since I have 3.73 gears?

Stock size 275/65/18 11.0 wide 32.1 tall

LT275/70R18 11.10 33.62

LT285/65R18 11.93 32.83

LT295/70R18 11.73 34.57

NorthernYankee

I have TG's on mine in 295/60-20 which is right around your 3rd choice, and they definitely impact my towing. I have a 5.0 with 3.73's and tow a ~7,000lb TT. If I had it to do over again I would go with something different, they are heavy and loud and at nearly 35" definitely reduce my power. But on a positive note they look AWESOME!

dbok

Thank you for the advice, If I decide to go with these tires, I hope the EB engine will help make up that difference.

smokeywren

Taller/wider tires will definitely affect your towing capability. You can compute the difference it will make.

The key is the percent change in tire revs/mile. Your rear axle ratio will change by the same percent as the revs/mile.

Here are the revs/mile for those sizes:
stock 275/65R18 = 648
275/70R18 = 627 = 3.2% change
285/65R18 = 636 = 1.9%
295/70R18 = 600 = 7.4%

3.73 - 3.2% = 3.61 effective ratio
3.73 - 1.9% = 3.66
3.73 - 7.4% = 3.45

All three of those effective ratios are still more than enough to tow 6,000 pounds. I towed 8,000 pounds last week with my EcoBoost that has 3.15 ratio, and no problems cruising at 65 MPH using cruise control and tow/haul mode on I-10 through the Hill Country northwest of San Antonio.

BTW, if you don't have the speedo calibrated to match the new tire size, your trip meter(s) and speedo will also be "slow" by that same percentage .

frieed

I'm towing 8000# of travel trailer and stuff with 3.55 gears and michelin 275/70r18's which puts my effective gear ratio at 3.55x32/33 = 3.44. No issues pulling it through the mountains here in Utah. none, zip, nada.
If you run a 34.5" tire your effective ratio is 3.73x32/34.5 = 3.45, just slightly more than mine.
Pulling a 6000# boat with lower frontal area than my trailer will not be a problem.