Tire Size, Lift, and Highway Driving Manners

[Packerjohn]

I'm looking to by a JK Unlimited. At this point it will not be used for any serious off-roading and will be our open air "fun" vehicle. Part of the fun would be taking it on vacations possibly up to 1000 miles one way. I looked at a nice 2017 manual Sahara with 35 in tires and a 3 inch lift being sold by a private party. He said with his set up he really couldn't do much more than 60 MPH on the interstate and really couldn't get it in 6th gear properly (didn't ask if he had any gearing modification) He was the original owner and never had it off road. We a had a stock Unlimited as a rental for a week and I didn't notice any issues running it 70+ on the interstate.

Was looking for thoughts on biggest tire size and lift combination that still has decent highway driving manners. I'm thinking anything with a lift would be out?

Appreciate your thoughts.

 

[BLACKJKU]

Sounds like my JK when I bought it, it had 35" tires on and 3.21 gears and couldn't use 6th gear. Just my opinion but that is a real bad combination, my guess the same with that JK.

 

[Anybodyhome]

If my off-roading was confined to basically overland and included long highway drives, I'd probably scale back from the 35s and the lift. Maybe dial it back to 33s and take an inch off the lift. Don't know that I'd want to drive 1000 miles without a 6th gear. I'll admit I'd be a little uneasy about the fact he can't run 6th gear and with 35s and the lift he can't do more than 60.

 

[Packerjohn]

If my off-roading was confined to basically overland and included long highway drives, I'd probably scale back from the 35s and the lift. Maybe dial it back to 33s and take an inch off the lift. Don't know that I'd want to drive 1000 miles without a 6th gear. I'll admit I'd be a little uneasy about the fact he can't run 6th gear and with 35s and the lift he can't do more than 60.

Thanks for your comment.

Yeah not planning on buying this one, although he has been lowering the asking price. The guy said it was his 6th Wrangler and is a doctor so I would assume not limited dollar wise to do it right and knew what he was doing. He said it would physically run 60 with the lift in 6th but not real comfortable.

I'm thinking I'm looking for no lift and up to 33 in tires (which I understand will fit with no modifications). My wife has a bit of a knee issue and doesn't want to get it scoped so want to make sure no issues getting in and out.

 

[Anybodyhome]

Thanks for your comment.

Yeah not planning on buying this one, although he has been lowering the asking price. The guy said it was his 6th Wrangler and is a doctor so I would assume not limited dollar wise to do it right and knew what he was doing. He said it would physically run 60 with the lift in 6th but not real comfortable.

I'm thinking I'm looking for no lift and up to 33 in tires (which I understand will fit with no modifications). My wife has a bit of a knee issue and doesn't want to get it scoped so want to make sure no issues getting in and out.

I have 35s on mine with a 3" lift, but it's an automatic. It'll run at 75, which is a survivor must on either I-95 or I-40. Much beyond that and it gets a little dicey, especially in the wind or other vehicles around you.
Regardless, good luck with your search and hope to see pics of the new addition to the family soon!

 

[Hooperdog]

I can run 85 in 6th gear on 37s, change the gearing it makes all the difference..

 

[Packerjohn]

I have 35s on mine with a 3" lift, but it's an automatic. It'll run at 75, which is a survivor must on either I-95 or I-40. Much beyond that and it gets a little dicey, especially in the wind or other vehicles around you.
Regardless, good luck with your search and hope to see pics of the new addition to the family soon!

Thanks much. Probably won't have anything for a while unless something drops into my lap. The top off season is pretty much over around here now and with Covid my 3rd garage stall is being used as my gym so would have to rent storage space. Plus used vehicle prices are so stupid now. Figure used prices will settle down and some lease returns will be coming up after the first of the year. If not, may just have to bite the bullet.

 

[Chris]

Tire size and weight is a huge contributing factor to the way a vehicle drives. One thing people seldom pay attention to is wheel weight and tire weight. Going from a 31" A/T tire on a lighter wheel to a 37" M/T tire on a heavy wheel makes an astounding difference in daily drivability, trust me.

A good example of this is comparing two similar size tires, but one being an A/T and the other being an M/T. The M/T will often times weigh up to 20 lbs. more in the same size, simply due to the thicker sidewalls and such. Think that doesn't make a difference? You'd be dead wrong if you thought that.

For this reason, I never suggest M/T tires on a street driven vehicle, and I also strongly encourage people to pay attention to the weight of the wheels they are running. Running the correct gear ratio is also very important. However, remember that the more weight you add (bumpers, winches, etc.), the more it's going to rob you of power.

 

[Packerjohn]

Tire size and weight is a huge contributing factor to the way a vehicle drives. One thing people seldom pay attention to is wheel weight and tire weight. Going from a 31" A/T tire on a lighter wheel to a 37" M/T tire on a heavy wheel makes an astounding difference in daily drivability, trust me.

A good example of this is comparing two similar size tires, but one being an A/T and the other being an M/T. The M/T will often times weigh up to 20 lbs. more in the same size, simply due to the thicker sidewalls and such. Think that doesn't make a difference? You'd be dead wrong if you thought that.

For this reason, I never suggest M/T tires on a street driven vehicle, and I also strongly encourage people to pay attention to the weight of the wheels they are running. Running the correct gear ratio is also very important. However, remember that the more weight you add (bumpers, winches, etc.), the more it's going to rob you of power.

Thanks for the input. Yeah thinking back to the HS Physics class and what happens to force as something rotates faster and/or has weight further from the center axis makes a lot of sense.

 

[Anybodyhome]

A good example of this is comparing two similar size tires, but one being an A/T and the other being an M/T. The M/T will often times weigh up to 20 lbs. more in the same size, simply due to the thicker sidewalls and such. Think that doesn't make a difference? You'd be dead wrong if you thought that.

This all day. I have 35 M/Ts and the tire wheel combo is right there at 110+lbs (82 lb tires and 32 lb wheels). Thankfully, the tires are going to be replaced this winter with the new Toyo Open Country A/T II or A/T III, which weigh about 69-75 lbs each

 

[cpwolf]

35’s on that year Jk with 3”lift is not a problem running 75 on the highway, smooth and in traffic.

Gear Ratio is certainly important, but I’d be a little stunned if I couldn’t drive over 60 in what is described.

Heck, with those ratios, just use 5th gear like it’s a 5 speed and I can do 75 and decent rpms.

I’d want to drive it to understand why it wouldn’t go into 6th? Is the shifter hitting the tub, the Synchros grinding? Or is he saying he can’t get going and use it? I’d want to drive that myself.

 

[Chris]

This all day. I have 35 M/Ts and the tire wheel combo is right there at 110+lbs (82 lb tires and 32 lb wheels). Thankfully, the tires are going to be replaced this winter with the new Toyo Open Country A/T II or A/T III, which weigh about 69-75 lbs each

Yep, if you can find a somewhat lighter wheel in the process as well, it may be worth it.

Thanks for the input. Yeah thinking back to the HS Physics class and what happens to force as something rotates faster and/or has weight further from the center axis makes a lot of sense.

Absolutely, the difference is profound. I've gone from 35" M/T tires to 31" C rated A/T tires in the same day, and the drivability difference is instantly noticeable.

I guess that's why when you get to the point where you start wanting to run seriously big, heavy tires, it's always a good idea to start looking at power adders such as superchargers.