To 32 or not to 32?

[SilicaRich]

Hello, fellow forumers! I have the grand question of whether or not to downsize from my current 33" tires or stick with them. I know, like why right? My reasonings are simple and subject to opinion but I'm truly curious how capable are 32"s? I love my 33"s offroad however they are killing me in the MPG department and feel like 32"s leave me with the perfect balance between offroad capability and road forgiveness. However, I'm building an overland rig and I'm afraid that 32"s will leave me potentially underbuilt for long haul trails. For instance, I had an Instagran friend just get done with one of the various Ozark overland trails and said it was tough, he had 35s on his LC. Then again, I've heard that 32s can get you through some remarkably difficult trails. I'm just a little undecided in my decision and some guidance would be nice. Trails pics would be nice if yall have them! Vehicle: 2005 Jeep TJR

I posted a nearly identical thread like this in Wrangler Forum, however, I'm already getting what I expected like "I would go to 35s" or "Stick with 33s, why would you downsize". Hoping I can get a more universal opinion from a broad range of vehicles besides the stereotypical Jeepers that only have a concept of going bigger. Side note, I have no desire to go to 35s, the budget to properly run them is far beyond what I would like to spend

Note: This is a future decision in no less than a year to happen, I just want answers ASAP

 

[tarditi]

I've been replying on the wrangler forum... good to xpost, though.

http://www.wranglerforum.com/f27/to-32-or-not-to-32-a-1462562.html

 

[jeep-N-montero]

Do you really think a 32 is going to make a difference in mpg vs a 33?? Given that you did not state the width of your 33's, I will take a guess and say you have a 12.50 width? If that is indeed the case then dropping to a 33x10.50 will indeed make a difference.

 

[SilicaRich]

Do you really think a 32 is going to make a difference in mpg vs a 33?? Given that you did not state the width of your 33's, I will take a guess and say you have a 12.50 width? If that is indeed the case then dropping to a 33x10.50 will indeed make a difference.

No I currently run 10.5". Thing is that if I want to stay with 33" tires, it would be best to regear to 4.56. With 4.10s, the powerband is still goofed up for 33"s, however, 4.10s are the proper ratio to run 32"s with my transmission

 

[SilicaRich]

I've been replying on the wrangler forum... good to xpost, though.

http://www.wranglerforum.com/f27/to-32-or-not-to-32-a-1462562.html

Good to see another crossover:sombrero:and, yes, I appreciate your responses on the forum. Problem is that I think a universal view on the situation is best, should have thought of that before posting originally on Wrangler Forum, which is filled with mostly guys/gals building rock crawler based rigs.

 

[tonkaman]

When you buy tires do you take into consideration the weight? This can make a huge difference! I'll bet shaving weight in tires would help MPG and with the slightly high gearing

 

[jeep-N-montero]

No I currently run 10.5". Thing is that if I want to stay with 33" tires, it would be best to regear to 4.56. With 4.10s, the powerband is still goofed up for 33"s, however, 4.10s are the proper ratio to run 32"s with my transmission

So why not simply re-gear and come out ahead anyway??

 

[4x4junkie]

Does anyone make a 32x10.50 or 32x9.50? All I've ever seen are 32x11.50s, which I think the extra inch width over your 10.50s would negate much of any mileage gains you'd get by the 1" smaller dia...

What tire pressure do you run? Maybe there's some room to up the pressure, which would significantly reduce their rolling resistance, upping your MPG.

 

[jeep-N-montero]

Does anyone make a 32x10.50 or 32x9.50? All I've ever seen are 32x11.50s, which I think the extra inch width over your 10.50s would negate much of any mileage gains you'd get by the 1" smaller dia...

What tire pressure do you run? Maybe there's some room to up the pressure, which would significantly reduce their rolling resistance, upping your MPG.

Nope, closest would be a 33x9.50 IF he can find a used set or upgrade to 16's and run 235/85's.

 

[Ducky's Dad]

Thing is that if I want to stay with 33" tires, it would be best to regear to 4.56.

The cost of regearing will buy a lot of gas. Everything is a tradeoff. Do you want ground clearance? Do you want flotation? Do you want heavy load capacity? Do you want M/Ts, or will A/Ts work for you? Do you want bullet-proof sidewalls? Do you need better effective torque at the low end? Sounds like a set of narrower 33s with a programmer for the engine might be your best compromise. The programmer will allow you to adjust shift points and may tweak the throttle tip-in response. Lots cheaper than regearing and changes the behavior of the vehicle to give some of the perceived benefits of regearing. You might think about CAI and freer exhaust to improve torque. Might even retard the ignition timing just a bit. Lots of ways to skin this cat.

 

[SilicaRich]

Does anyone make a 32x10.50 or 32x9.50? All I've ever seen are 32x11.50s, which I think the extra inch width over your 10.50s would negate much of any mileage gains you'd get by the 1" smaller dia...

What tire pressure do you run? Maybe there's some room to up the pressure, which would significantly reduce their rolling resistance, upping your MPG.

I believe they offer a 32"x10.5" in a 15" rim but I'm swapping back to stock 16" rims. I currently run 28-30 psi across all 5 tires. Problem is that I'm not entirely sure how accurate that is since I've only put 300 or so miles on it in the last 5 weeks so there's chance of error there. Maybe next gas fill up I'll run it over to the air station and bump them up to 32-33 psi. 28 psi is just what's recommended for comfort and ride.

Nope, closest would be a 33x9.50 IF he can find a used set or upgrade to 16's and run 235/85's.

235/85 would probably be too thin for my liking. I like thin but not that thin. I actually already have a seller lined up to buy a set of almost perfect 16" Moabs with 31" tires mounted for $250. Reason I don't want to regear is for the fact that I would like to keep everything most of the mechanics stock so there's "less room" for potential failure. Also, the quotes I've gotten are absolutely ridiculous in price. Plus, I'm actually not "properly" even built as of now to run 33" tires. Original owner basically put on the cheapest 4" lift available and threw in a T-case drop to finish it off. I would still need to invest in adjustable CAs and various other goodies that actually exceed the budget than to just downsize, that's including a regear for the right price.

In confession, I actually told myself while shopping for a Jeep that I would find the closest to stock one available and never go beyond 32" tires for the sake of cost to maintain and simplicity. Yet, in that mentality I ended buying a slightly, yet enough to be a pain, modified Jeep with low miles.

 

[Ducky's Dad]

A 4" lift will kill gas mileage at highway speeds, regardless of what tire you are running.

 

[SilicaRich]

The cost of regearing will buy a lot of gas. Everything is a tradeoff. Do you want ground clearance? Do you want flotation? Do you want heavy load capacity? Do you want M/Ts, or will A/Ts work for you? Do you want bullet-proof sidewalls? Do you need better effective torque at the low end? Sounds like a set of narrower 33s with a programmer for the engine might be your best compromise. The programmer will allow you to adjust shift points and may tweak the throttle tip-in response. Lots cheaper than regearing and changes the behavior of the vehicle to give some of the perceived benefits of regearing. You might think about CAI and freer exhaust to improve torque. Might even retard the ignition timing just a bit. Lots of ways to skin this cat.

You are telling me:Wow1:I've about researched enough to use this topic as my senior thesis. I actually have an AFE intake (stock one had a hole melted in the box, don't ask) and a MF exhaust. I've actually considered a programmer and bought a Diablo Trinity back last year, however, I bought a defective unit that kept crashing before I could set it up, Diablo almost didn't give me a refund because I "wouldn't update it" (it kept crashing as it updated). The experience left me pretty irritated with Diablo, however, I intend to give it another try in the future. Although, I'm not sure how much they would adjust the shift points since it's a manual, however, a programmer should be able to help adjust the fuel maps. I honestly need to get back to Texas so I can be served a beer and can relax about this topic haha

And that's why I want to downsize to the 2.5" lift regardless of tire size

 

[Ducky's Dad]

bought a Diablo Trinity back last year, however, I bought a defective unit that kept crashing before I could set it up, Diablo almost didn't give me a refund because I "wouldn't update it" (it kept crashing as it updated).

Pretty much the same experience I had with a Diablo Predator for my Dodge Hemi. Bought it new, couldn't get the thing to update, kept timing out and crashing during the update. Wouldn't load onto the truck without the update. POS. Put it away so that I could deal with it later, and that was about eight years ago. Just got an Edge Insight CS for that truck and it worked just fine, update was straightforward, took about an hour on a DSL connection. Truck is much more pleasant to drive now, especially in the mountains, even on fat 35s replacing the factory 33s.

 

[SilicaRich]

A 4" lift will kill gas mileage at highway speeds, regardless of what tire you are running.

Pretty much the same experience I had with a Diablo Predator for my Dodge Hemi. Bought it new, couldn't get the thing to update, kept timing out and crashing during the update. Wouldn't load onto the truck without the update. POS. Put it away so that I could deal with it later, and that was about eight years ago. Just got an Edge Insight CS for that truck and it worked just fine, update was straightforward, took about an hour on a DSL connection. Truck is much more pleasant to drive now, especially in the mountains, even on fat 35s replacing the factory 33s.

Only problem is that last time I checked, Edge doesn't make a programmer for a Wrangler. Diablo to my understanding is the only one compatible with a TJ that has on-the-go programming

Edit: Superchips makes one that is TJ compatible and has on-the-go programming