Can I make the switch to a larger wheel without facing other issues?

[BobK]

I was talking with my adult son today and wheels and tires for the 203 TJ project that we're working on and I mentioned that I was looking at 15 wheels and 33 x12.5 tires. He asked "why 15 inch wheels, just move up to 16 or 17's.

To be honest I was just following along with what was already on the Jeep. Can I make this switch without incurring additional issues? I have already installed a 1" BL and MML and will be working on a 2" coil and shock lift in the next week or so.

My plan is to use BFG KO2's and can get them in 15 or 17 inch sizes. The question also is, how would I determine what speedometer gear to replace to correct the speedometer?

 

[S.McArthur]

Tire will be the same size in regards to overall height, you will lose sidewall rubber though.
15/33” look very good, I had to go to the jk 17” wheel, it looks fine but I’d like a little meatier sidewall. 15” wheels just fit well with the TJ fender wells.
Good luck finding a variety of 16” tires to choose from, not worth going with them.
17” wheels look kind of big in the TJ wheel wells, but not terrible.
Here’s mine with 17” JK wheels and 33” tires.

 

[MountaineerTom]

15 inch wheels will give you a greater selection of tires in the proper C load range at better prices, in my opinion. 17's look to big for me.

 

[astjp2]

I was talking with my adult son today and wheels and tires for the 203 TJ project that we're working on and I mentioned that I was looking at 15 wheels and 33 x12.5 tires. He asked "why 15 inch wheels, just move up to 16 or 17's.

To be honest I was just following along with what was already on the Jeep. Can I make this switch without incurring additional issues? I have already installed a 1" BL and MML and will be working on a 2" coil and shock lift in the next week or so.

My plan is to use BFG KO2's and can get them in 15 or 17 inch sizes. The question also is, how would I determine what speedometer gear to replace to correct the speedometer?

You can tell your son that you are not driving a ricer...sorry I could not resist. If you are only on pavement, 17's are plentiful and easy to get and more than adequate. I just put 33x10.5x15 KO2's on my LJ a few weeks ago. I prefer narrower tires and 15 inch wheels so I dont sling shit up the side of my jeep or into anyone's windshield and a descent ride.

 

[Jerry Bransford]

Stick with 15" wheels for up to 35's. Your son might just be more thinking bigger wheels are more stylish. You'll get more tire flex for better traction with 15" wheels and a better ride too.

 

[Chris]

@mrblaine had said something in a thread of mine a while back.

I had mentioned that it would be nice to have a 15" wheel due to the larger sidewall of the tire (assuming the tire on the 15" and 17" wheel was the same size). Blaine mentioned that sidewall technology has come so far that having the larger sidewall on the 15" wheel is no longer an issue like it once was.

Take that for what it's worth, but a lot of people are running 17" wheels now and there is a lot of wheel and tire options out there for that size. Personally I wouldn't hesitate to run a 17", just steer clear of 16" wheels as the tire selection is drastically limited.

 

[Unacceptable mouks]

The question also is, how would I determine what speedometer gear to replace to correct the speedometer?

You can find a chart here:
https://www.quadratec.com/c/reference/jeep-speedometer-gear-tooth-chart

 

[JEEPCJTJ]

Maybe your son doesn't like the ricers but would prefer something like this:

 

[Jim King]

Sweet! Is that an early 80's Caprice Classic?

 

[crackedcornish]

I like my 15's, but I grew up with them on my CJ-7, and on my current YJ and TJ...If I'd grown up with JK's instead who knows

I guess if I were wanting bigger brakes I would go bigger rims, but otherwise I'm happy with the lower price tag of the 15" tires

 

[Mikester86]

I am running 33" x 12.5" x 15" on 15" x 8" American Racing rims and couldn't be happier!

 

[Mr. Bills]

17's are the new 15's. Since JK's and JL's come from the factory with 17" wheels there seems to be an ever increasing selection of 17" wheels and tires including many tires with "C" and "D" load ratings.

The selection of 15" tires is relatively stagnant and may actually be decreasing, but that shouldn't be much of an issue for jeep owners for many years. There are several good tire choices with a "C" load rating, which is the load rating that best matches the weight of a typical TJ.

Most AT and MT tires for 16" wheels have "E" load ratings, which as one would expect are stiffer than "C" load rated tires, but not as stiff as some who have never run an "E" load rated tires on a TJ like to characterize them. Still, 16" wheels and tires would probably not be the best choice unless one has a particular reason to want to run them.

 

[astjp2]

My tire guy claims that his distributor says that the BFG in 15" is going away, but I have heard that for 10-15 years. Same for muscle car 15" tires, they only run them every couple of years so when they available people grab them up.

 

[BobK]

Thanks to all who responded, I appreciate the comments. The older son lovers "ricers" and has a Honda Civic Type-R that would blow away all the ricer-wanna be's. The son who asked about 17's is actually a truck and Jeep kinda guys (assists me with my Jeeps and online store). His comment was only based on the dearth of choices in 15" wheels. In fact, he first picked out a beautiful chrome 15" before he asked about optionally choosing other sizes.

I should have considered the sidewall aspect before even posting and after looking at pricing of 15 vs 17 wheels and tires, the path towards 17's would be more expensive. We're back to following the 33 x 12.5 x 15 path......

 

[astjp2]

You really cant go wrong with the 15's, if it is just a driver and not a show piece. These are 33x10.5x15 BFG all terrains on an 05LJ.

 

[BobK]

Since we are on the topic of wheels, with the 1" BL and 2" coil/shock lift I'm doing, what is the optimum wheel width, backspace, and offset. I do not mind (in fact like) the look of the tire outside of the fender flare (but not by a huge amount).

The 15" wheel I'd like to get comes in an 8" width and a 10" width. BFG suggest an 8.5 to 11" width for the 33x12.5x15 KO2. This same wheel has a -46 offset, which if I understand will cause the tire to stick out of the fender flare (factory) and it has 3.625 backspace.

The -46 offset seems high to me. What is the minimum offset necessary to have a stable mounted wheel that clears the brakes and would eliminate the chance for rubbing?

As I mentioned in the original post, its getting harder to find a selection of 15" wheels.

 

[Mr. Bills]

The typical recommendation is to run 8" wide wheels with 12.50" wide tires. Reasons given usually include that the narrower width better protects against "popping" a bead at extremely low tire pressures. However, for the vast majority of jeepers this is a non-issue. I have run both wheel widths over the past 50+ years in many types of terrain and at very low tire pressures without any adverse incident. It is purely a matter of personal preference.

The bottom line is that one can run either 8" or 10" wide wheels with 12.50" wide tires so pick the width that you prefer, whether it be for reasons of aesthetics, availability, or whatever.

_____________

P.S. - Forget offset. Without getting into the reasons why, it is not a particularly useful measurement for jeepers.

The measurement you need to focus on is backspacing - the distance between the wheel mounting surface and the inside edge of the wheel. Optimum is 4" backspacing with an 8" wide wheel, although some like the tires "pushed out" more with 3.75" backspacing. Generally speaking, backspacing of 3.75" - 4.25" should work with your desired 33x12.50R15 tires, perhaps as much as 4.5".

 

[BobK]

The typical recommendation is to run 8" wide wheels with 12.50" wide tires. Reasons given usually include that the narrower width better protects against "popping" a bead at extremely low tire pressures. However, for the vast majority of jeepers this is a non-issue. I have run both wheel widths over the past 50+ years in many types of terrain and at very low tire pressures without any adverse incident. It is purely a matter of personal preference.

The bottom line is that one can run either 8" or 10" wide wheels with 12.50" wide tires so pick the width that you prefer, whether it be for reasons of aesthetics, availability, or whatever.

The 8" width seems to be more available and less expensive. I've found two similar wheels in 8" width that have either a -27 or -19 offset and a 3.5 or 3.75 backspace. Are there any suggestions relative to the offset or backspace to ensure clearance? These seems pretty close in specs.

 

[Mr. Bills]

As noted above in Post #17, forget offset. The measurement you want to focus on is backspacing.

In my opinion, 4" backspacing is optimal for an 8" wide wheel with 12.50" wide tire. 3.75" backspacing is commonly used. 3.5" backspacing would look like skateboard wheels to me.

 

[89grand]

3.75"-4" seems to be the preferred back spacing, but 3.5" won't look like a skate board, it's only .25" difference from the norm. I used to run some Ion Alloy wheels and the back spacing was 3.44". There wasn't much visual difference between them and my current wheels that are 3.7".