Trying to make decision on tire size for my 2010 Jeep Wrangler Unlimited

[Snowbird Tom]

Sorry for the delay. I have confirmed that I have 373 gears. I have heard that the 3.8 lacks some power as it is. I have some factory 18's and some LT 275/70 R-18 which I think calculates out to a 33 in tire. I thought about those, maybe some wheel spacers and a 2 inch puck lift. However, if that is going to make this thing a complete dog, I will just stay factory tire size and maybe do the puck lift and then add the spacers. Thanks

You probably missed my response above, so I will repeat. I have 3.73s and with the 33x12.50-17 MT tires, I had more than sufficient power to get the Jeep moving and run up past 80 on the freeway rather sportily. Granted, this is NOT a road performance vehicle like a Mustang or Corvette. When I put the 35x12.50-17 XT tires on, I noticed a decrease in pulling power with a moving trailer connected, but it still moves along nicely unladen. Daily driving, no issues whatsoever.

I have yet to get it out on local trails due to the move back home from our winter spent in Houston. Too much work in the yard and house after being gone six months. I did just receive a "9 Drive" gas pedal performance enhancer today, recommended elsewhere on the site to improve the throttle response.

 

[Dirty Dog]

You probably missed my response above, so I will repeat. I have 3.73s and with the 33x12.50-17 MT tires, I had more than sufficient power to get the Jeep moving and run up past 80 on the freeway rather sportily. Granted, this is NOT a road performance vehicle like a Mustang or Corvette. When I put the 35x12.50-17 XT tires on, I noticed a decrease in pulling power with a moving trailer connected, but it still moves along nicely unladen. Daily driving, no issues whatsoever.

Driving at low altitude on relatively flat terrain helps a lot. Come visit us, where you start at 5000 feet and spend much of your time vertical...

 

[Snowbird Tom]

Driving at low altitude on relatively flat terrain helps a lot. Come visit us, where you start at 5000 feet and spend much of your time vertical...

BTDT with dirt bikes. Totally readjusted the carburetor before starting the two week back country adventure on my KLR650 to get a modicum of power back. It’s going to be very rare for me to get back out that way anytime soon, unfortunately.

99% of my Jeeping will be at low altitude.

 

[Dirty Dog]

BTDT with dirt bikes. Totally readjusted the carburetor before starting the two week back country adventure on my KLR650 to get a modicum of power back. It’s going to be very rare for me to get back out that way anytime soon, unfortunately.

99% of my Jeeping will be at low altitude.

There are places out here that will require carb adjustments mid-trail. Score one for EFI!

 

[Snowbird Tom]

There are places out here that will require carb adjustments mid-trail. Score one for EFI!

Yeah. We started in Rawlins, WY and cleared 10k several times. Five states, 2100 miles, 90% off pavement. It was the trip of a lifetime.

I learned about hills and underpowered tow vehicles on that trip.

 

[MacGuyver]

Probably not worded very well above.

JK is 2015, 35,000 miles, 3.6, std 6sp and stock size tires. Symptoms below are when off roading at elevations above 5,000 feet (then again don’t really do much local here in town), usually in the Sierra’s, and on inclines.

1. When going 5 mph going uphill the Jeep has a tendency to stall. It simply like it doesn’t have enough power, rpm’s are just too low, say around 1,000-1,200 and they end up dropping regardless of how much pedal I give it. They just drop and it stalls.
2. Once the above happens it seems basically impossible to start it. I can step the gas get the rpm’s up to let the clutch peddle out and the rpm’s just drop and it stalls out again. It’s simply like there isn’t any power.

I can shift the transfer case into 4L and the problem is immediately resolved as the rpm’s stay up above 1,000 and it has enough power due to gearing ratio. When in 2 wd or 4H it’s like the Jeep just doesn’t have enough rpm (power) to climb a hill at 5 mph. I don’t believe it’s a situation of the hood insulation getting sucked down into the air intake as it doesn’t happen on the road traveling up the sierras (and there are some decent grades) plus put it into 4L and the issue goes away. Just have a hard time thinking people with a 6sp change from 4H to 4L each time when climbing a grade at 5mph, but maybe they do. Or they do like me and just travel around in 4L all day since only going 5 mph or so. I just shift gears, been up to 4th gear doing 5mph in 4L. Most people I go jeeping with have auto’s so hard to ask them.

Is the hood insulation getting sucked into the air intake?

I do see your torque curve for the YJ. Older engines had a much lower torque curve. I have a TJ with a 4.0 and a 3.8 JK. Both are manual and I shift around 700 rpms lower on the TJ than the JK. And your 3.6 is even higher torque curve than the 3.8.

 

[Danarch]

Is the hood insulation getting sucked into the air intake?

I do see your torque curve for the YJ. Older engines had a much lower torque curve. I have a TJ with a 4.0 and a 3.8 JK. Both are manual and I shift around 700 rpms lower on the TJ than the JK. And your 3.6 is even higher torque curve than the 3.8.

I think it is just a matter of the torque curve. All the rest of time it works just fine.

 

[Jackpot]

You probably missed my response above, so I will repeat. I have 3.73s and with the 33x12.50-17 MT tires, I had more than sufficient power to get the Jeep moving and run up past 80 on the freeway rather sportily. Granted, this is NOT a road performance vehicle like a Mustang or Corvette. When I put the 35x12.50-17 XT tires on, I noticed a decrease in pulling power with a moving trailer connected, but it still moves along nicely unladen. Daily driving, no issues whatsoever.

I have yet to get it out on local trails due to the move back home from our winter spent in Houston. Too much work in the yard and house after being gone six months. I did just receive a "9 Drive" gas pedal performance enhancer today, recommended elsewhere on the site to improve the throttle response.

Well, that is basically exactly what I was thinking about going with. I was just wondering if the 3.8 would have enough power. Thanks for the reply. I really appreciate it.

 

[Jackpot]

Well, no. What I'm saying is that if you want to swap on bigger tires (and who doesn't?) you need to ALSO do a gear swap, or accept that your Jeep will be a slug. And you'll probably also want to do a lift. And some fender flares with more clearance. Maybe some trimming... Ohhh, lockers!

This is why people aren't really joking when they say that JEEP is an acronym for Just Empty Every Pocket.

Man, that is no doubt. I am going with the 2 inch puck lift, but I really didn't want to worry about doing the gear swaps and having all of that cash in it. I may consider just upsizing the tire by one size or so and just staying a little closer to stock until I get the money for the gear swap thing.

 

[Snowbird Tom]

Well, that is basically exactly what I was thinking about going with. I was just wondering if the 3.8 would have enough power. Thanks for the reply. I really appreciate it.

Mine’s the later model 3.6l 285 hp from 2016.

I bought it like this in September.

This is now. Those dangling wires are now connected, wrapped and sheathed for protection.

 

[Jockey 19]

Thanks for the advice, I will skip the spacers for sure. Maybe I will just stick with my plan for the 33's and install the 2 inch puck lift and see how she performs. Would It look out of place if I did the 2 inch puck lift and just did like a 31 inch tire?

I have factory wheels that I was going to use and when I purchased all of the factory painted flares and bumpers I needed on Marketplace, a set of hub centric spacers came with them but they are 1.5 inch vs 2 inch that I thought. I also have a set of Aftermarket 17 inch wheels I purchased on marketplace, but I would have to buy new tires for that. The aftermarket wheels do no seem to have much more of an offset than the factory though. Maybe a little. sounds like if I stay w/ around a 32in tire that I should be able to maintain power w/out a ton of modifications. I am also trying to avoid the death wobble !!!