I've finally decided to go with a 33x10.5 mounted on 15x8 wheel. This is for a '13 2 door auto 3.73 daily driver. I dont do any heavy offroading requiring taller or wider tires. I have seen the "general rule" that a 15" needs 3.75 backspace. From what I gathered this is so you don't rub on brake calipers and suspension components.

Will a 5" backspace on 15" alloy wheel rub on said components? Not worried about hitting fenders or stuffing. I will level it if I have to.

 

Higher backspace moves into the wheel wells, lower backspace moves out of the wheel wells.

If the general rule is 3.75", how does moving the rim in another 1.25" (toward the calipers) gain you more room to clear them?

On a larger rim where caliper clearance is not an issue, a 5" BS would be fine for a 33x10.50 to clear the other components.

 

I'm not trying to clear the tires, just the calipers. I understand the higher number moves it in, which is precisely what I am trying to do. Trying to keep the tires under the fender. I have seen a jk with 33/10.50r15 with 3.75 backspace and the tire was still outside the fender. Barely but still outside none the less. I have heard of people running pintlers that have 5.2" backspace and 35/12.5r17 and only rubbing the fenders (maybe air dam ). my main concern is the 15 with 5" clearing the calipers.

 

I think that will depend on the design of your wheels. For example my 15" wheel, the whole barrel is not the same diameter. It is more narrow from the mounting surface to the outside of the wheel. From the mounting surface to the inside of the wheel it is a larger diameter. If the design of my 15" wheel wasn't like this it wouldn't have cleared the calipers.

I would say buy the wheels and mount them up. If it works, great. If it doesn't, pick up some spacers and then you'll be good to go.

 

TUFF T03 WHEEL 15X8 6X139.7 / 5.5" BOLT PATTERN -13MM OFFSET BLACK FINISH - BB Wheels

This is a general link to see it. I have the exact one on my computer at home with 5x127 +12. Don't know if it helps or not. I would like to stay away from spacers. If it won't work I may go to a similar 17". If I can find a local shop that will order them I may do that, but don't want to jack with retu thing such large items. I've done it once and it was a pain.

 

We have fit 15x8 steel wheels with 4" back spacing. The wheel just barely touched the casting marks on the caliper. We were able to smooth the casting marks out and made the wheel fit.

With the 5" back spacing it might be a lot worse but it will also prevent you from future upgrades such as a tie rod and some lift kits. Personally I would not recommend running that wheel.

 

You missed the point. A 17" rim has more space in the middle of the rim to help keep the rim away from the calipers/rod ends/etc. A 15" rim has less space in the middle of the rim, so it needs to be moved further out to keep from contacting the calipers/rod ends/etc. The 17" rim you mentioned can get away with a 5" backspace simply because it has more room in the middle, and people are going with 4" or 3.75" backspaces on 15" rims simply because higher numbers are too far in and contact the brakes/ends...

If you want to run 15's, you need to either move them out or be willing to do some grinding.

This one has a list of 15" rims that DTD guarantees will fit.
https://www.jk-forum.com/forums/spon...wheels-120933/

And this one has a formula to convert offset to backspace if you need it.
https://www.jk-forum.com/forums/modi...relate-136663/

 

short answer: no.


Like those before me have stated, you will contact your caliper long before you even get the lugs torqued down.

 

I understood about the 17 and you answered the question about the 15s too. Sorry if I come across as am a-hole but I'm not the best at putting my thoughts into coherent sentences in writing.

 

Thanks for the clarification. ... back to the drawing board.