It may just be me. I drove for 4 months before swapping tires. My friend was driving with me yesterday and she said she had no idea what I was talking about. It ran pretty good to her. I'm just wondering if I'd be better off with the lighter Ko2 instead of the Load E grapplers that I have. But does the 15 lbs per tire difference really make that much of a difference?I swapped my tires out when it had like 21 miles, and half of those miles were from dealer prep/test drive. I don’t really know any different than what it is like now.
I know for certain that the acceleration is WAY better than the Jeep I sold when I got the new one. The old one was a 2011 with the 3.8L, 33” tires, and 3.73 gearing.
This new Rubicon accelerates plenty good in my opinion with the manual transmission, 35” tires, and 4.10 gears.
315/70 r17 BFG KO2 with Black Rhino Warlords 17x9 with a -12 offset. Here are a few pics. A couple that show the before and after.
It might just be that I drove stock for a few months and now with the 35s I notice it even though it’s slight. My husband didn't seem to think it’s any different.I really don’t think the weight of the wheels/tires makes much of a difference. I have rather heavy wheels and load range E KO2s for a total weight of around 115 lbs. My Jeep (automatic) didn’t feel noticeably different to me.
Edit to add: yes I did recalibrate for the larger tire size.
Hey, I did not get anything else done. I'm running at about 40 psi. Died think it's too high! Lmk how it goes after you drop yours! My mph is off by about 4 (jeep shows 4 less). I had my stock Rubicon wheels for about 4,000 miles so I do feel a difference with the 35's. Sluggish is a good word. Slightly Sluggish!Hey Mike,
Your set up weight wise is about the same as me 100 lbs per tire. Did you get your jeep recalibrated? Just curious if this will make a difference to me or not in the sluggish feel. I know I should get it done for the accuracy of the mileage.
I am still running my tires at 37 psi because of the sensors. I'm going to try and lower it today to see how it drives but honestly even at 37 aint too bad.
Perhaps lighter tires would make a difference. The Nittos are 13 lbs heavier than the Ko2 and load E. I’m ready to go back to stock because I worry. Although I called the dealer today and they said I should be fine as long as I calibrate. I’ll try that first.Not sure about the sluggishness as I drove mine around before I installed the TazerJL, and, of course after, for the speedometer calibration. I did not notice any change in the vehicle being sluggish, however, I do have the automatic. Calibrating the speedometer will help, but I doubt it has an effect on the tranny in a manual vehicle. If your unhappy with the fact that it seems sluggish to you, a regear will help with that, perhaps stepping into 4.88 gears but I would do a bit of research if that's the route you'd like to proceed with. Your gas mileage on the highway will suffer from a regear, but it would feel better around town.
True, E rated tires are much heavier as compared to C rated tires like the original K02's. Seems to be some concern about sluggishness in a few briefly read articles and forum posts:Perhaps lighter tires would make a difference. The Nittos are 13 lbs heavier than the Ko2 and load E. I’m ready to go back to stock because I worry. Although I called the dealer today and they said I should be fine as long as I calibrate. I’ll try that first.
You’re not going to hurt anything by driving for a while on 315s. I drove with 35s for 70k miles in my old F150 without recalobrating. No issues other the speedo and odo were off.Hi All,
Not sure if this is the correct thread, but here goes: I'm mounting BFG 315/70/17 KO2s on my 19 JLUR next week. 4WheelParts sells a module to reprogram the speedo for 35" tire size. Anyone have recommendations on cal modules? Surprised at the price on these just to change the cal of the diameter. Also, the 315/70s are actually 34.4" in dia, not 35 as I understand. Anyone know if you program for specific tires or diameter (in tenths of inch, for example)? Or is it just 33, 34, 35? Not sure what to do here and don't want to drive too much until I get this re-calibrated for the 315s.
Thanks! I just didn't want to be driving with inaccurate speedo and clocking miles with error. Thanks for the Tazer tip! I'll look for it.You’re not going to hurt anything by driving for a while on 315s. I drove with 35s for 70k miles in my old F150 without recalobrating. No issues other the speedo and odo were off.
Regarding a programmer to change tire size, go with a Tazer. You can get the Lite version if you don’t care about the live features. You can always upgrade later to the full version. The Tazer allows for very fine adjustment of the tire size.
I’ve got 315s on my 2019 JLUR and they “fit” with the swaybar disconnected but they do rub slightly on the rear inner fender at full stuff.@Spike:
I like the look. Doing the same until I find a lift kit (currently waiting to see what AEV does). But have you done any moderate off-roading or disconnected the sway bar to see if those 315s still fit? I see two schools of thought on these threads. 315’s and 35”s are no problem without a lift and others that say they will interfere.
Anyone else with actual experience? I have a ‘19 JLUR, no lift, but Tuesday the BFG 315/70/17s go on. Need to work out the spare carrier also.. different thread.