JKU Lift/Wheel/Tire combo Sanity Check

[jkilgore11]

Thanks! I originally debated on the AEV spacer kit, but I think it would be a wise decision to save my money and go with a complete kit. I have the Pintlers and 285/70/17 tires. I should look good and give me a lot more capability off road based on what you guys have said.

 

[AEV]

Thanks! I originally debated on the AEV spacer kit, but I think it would be a wise decision to save my money and go with a complete kit. I have the Pintlers and 285/70/17 tires. I should look good and give me a lot more capability off road based on what you guys have said.

It definitely will give you more capability as it's a complete suspension system. It by far improves the comfort of the ride over stock.

What color Pintlers do you have?

 

[jkilgore11]

I have the black on a 2016 Billet Silver JKU Sport S. 3.73 gearing.

 

[donaldj]

OK folks, I did a bit of a change up and ordered the 315/70R17's. Yes, it'll be a bit lower off the go, but I decided that rather than save up for tires and regearing in the future, I might as well get what I want and regear when I save that. One step ahead.

I'm not going to be towing until next year, so this should be OK.

 

[OlHeadz]

Going with the 315/70/17 right from the start is a good choice. I went with 285/70/17s first and after about a month kept thinking they looked too small. I have the 3.73 gears and with the 285, the highway ride and acceleration was still really good. I ended up selling the 285s and went with a 35/12.50/18 on Method Racing wheels and the look of the vehicle was transformed. Unfortunately, the highway ride suffered too. Going up hills I now have to down shift to 5th or even 4th to maintain acceleration, which in the end affects gas mileage. With that being said, I still average between 16-18 so I'm not too upset.

Off-road the vehicle still performs adequately, but there was some getting used to having to give the vehicle a little more gas to get those big meats moving. After talking to about three companies and some other JK guys while off-roading, I am going to go with the 4.56 gears and Artec trusses next spring. This should give me the basic feel of the 4.10s and the 31" tire. I drove my brother in-laws 2012 Rubicon with the 4.10s and the difference on and off road was huge.

I daily drive my JKU and around town the ride is perfectly acceptable. It is when I am on the highway and off road where the difference comes in. On another note, I have a 2.5" lift using Metalcloak springs, Rancho shocks and JKS disconnects. This lift with the 35s makes a really capable off road vehicle. I'm not doing any serious rock crawling, but some of the more difficult trails are no problem, except for the issue I described earlier. After the regear, this thing will be great. I did trim my oem flares to provide clearance due to the 35s rubbing when articulated. So I would recommend a wider or flat flare, or just trim the oem ones.

My JKU is my first jeep and truck in general so my observations are strictly from this narrow perspective. Good luck with your build.

 

[donaldj]

Hello all,

The new wheels and tires are now on!

Here's some info I couldn't find elsewhere:

• The AEV 2.5" lift lifted the front about 3.25" and back about 3".
• The BFG KO2 315/70R17 tires measure 33.5" high on the vehicle. Tire pressure @ 40 psi. On an unloaded Wrangler JKU.
• The BFG KO2 315/70R17 tire fits on the stock spare tire carrier. The rubber bumpers do not contact the tire any more.
• There was perceptible but not unlivable reduction in acceleration.

 

[jkilgore11]

Looks awesome! Love the black out!

 

[Blue Baby Sound]

Congrats!!
IMO 40 psi is way too high. Do a chalk test and you'll likely find that 26-28 psi is where you should be.
Jeep is looking good!!

 

[Comanche Scott]

Congrats!!
IMO 40 psi is way too high. Do a chalk test and you'll likely find that 26-28 psi is where you should be.
Jeep is looking good!!

x2! :beer:

 

[Ragman]

Post trip update

We just put the 3.5 inch AEV lift on our JKU 2015 Rubicon along with 35 inch Cooper STT Pros. The JKU came stock 6-speed manual with 4:10s and is still ok with the 35s (mathematically near 3.73s now but I do honestly miss the feel of the 4:10s. At the moment I would call it a more relaxed ride relative to acceleration and can definitely feel the loss of power on the highway in 6th. I tend to drive now in lower gears and expect I will regear to 4.56 before long. Not mandatory now but I think it would be prudent if towing anything.

35s with stock 3.73s I think you will miss the acceleration.

UPDATE

Just drove across SD and WY through the contours and always present strong winds. Totally feel like the regear is absolutely necessary as the Jeep could not maintain speed limit in 6th and often 5th. At some points 4th was required. Now that is what gears and revs are for but it made one eight hour trip with frequent shifting more tiring than I expected and the subsequent beer at the lodge that much sweeter.

Now in all fairness the speed limits are 80 on the freeways which JKs aren't really designed for, but it is a sinking feeling when I am being passed by semi trucks on the hills!

As a side note started trip with tires at 35 psi and found the ride a bit busy. Aired down to 32 and that felt pretty good for highway travel. As time and temps rose the psi was running as high as 37-38.

 

[Jeep or Tacoma]

I have an 08 rubicon with 410s I thought about buying a new one more power etc, one of the ones I drove had 373 mine is an auto and so was the new one I could really tell much difference, that being said everyone told me that I would hate putting on 315 70 on my 08 ruby w 410s . But honestly it is just fine, for me anyway I think that the newer motor with 373s would be fine probably better than the older motor 410s and 315s

 

[n1as]

My 2015 JKUR has 3.73 gears and a TF 2.5" suspension lift with AEV drop brackets. I went with 285/70/17 tires. They are lighter than 315's which helps with accel and braking. The reduced weight also allows me to stick with the OEM tire carrier. They are shorter than 315's which helps with accel and braking. The are shorter than 315's but the loss in ground clearance is a tolerable 3/4 inch. They do not hit anywhere under max flex.

Oh, and my short wife's ability to leap into the Jeep means the taller 315's would be too much for her.

The ONLY drawback to the 285's from my perspective is that they look a bit small. I'd love to have the looks of the larger 35" tire but I do not want to live with all of the downsides.

 

[jkilgore11]

I am in the same boat minus the 2.5" lift that I haven't pulled the trigger on. 285/70/17's with 3.73 gearing. Acceleration, braking, and fuel mileage are pretty close to stock. My tire sizes and gearing choices have changed a lot over the years based on purpose and where I live at the time. Before purchasing my recent JKU, after two swaps the final setup on my last Jeep was 35/12.50's and 4.56 gearing. It was great for the mountains, but was a bit too much for my current needs. Also, my wife didn't like the setup with custom 4.5" lift and coilovers. She wasn't comfortable getting in and out or driving it. She loves the new JKU and doesn't want me to go any bigger than a 2.5" lift. The problem is that I don't get to drive it as much. Guess I need to get used to being chauffeured.

 

[kojackJKU]

I am running the teraflex leveling kit with is 2" front and 1" in the rear with 285. I use it off road ALOT and never wanted or needed anymore. Jeeps are very very capable off road, and keeping it low and light means it still drives fine on the highways. I did a 4 hr run today on the highway in high winds and it only drops a gear on hills. doing 70 mph.

 

[Kmrtnsn]

I am running the teraflex leveling kit with is 2" front and 1" in the rear with 285. I use it off road ALOT and never wanted or needed anymore. Jeeps are very very capable off road, and keeping it low and light means it still drives fine on the highways. I did a 4 hr run today on the highway in high winds and it only drops a gear on hills. doing 70 mph.

Not to mention, the weight per tire penalty at each corner going 315/35 versus 285 is about 12 pounds on average. That's a 12 pound penalty in a larger rolling mass. That affects both acceleration and braking efficiency in a significant manner.