btadlock

2009 JKUR, 2 3/4 front, 2 in rear, currently running 285/70x17 on stock Rubi rims, looking to go a bit larger, what is the biggest tire size I can run before I need spacers?

Would like to stay with a 70 series tire to keep some width, but if going to a 65 will get me taller tires and keep me away for spacers, I would consider.

Nothing against spacers, just trying to save the $$ for other items.

Thanks.

tarpon4me

nothing wider than 11". even then, at full lock disconnected you'll rub a tad. I fixed this with my stock wheels by adding washers to the steering stops.

btadlock

Thanks, went the additional washer route on my TJ.

MotoJeeper

I think you're getting metric and standard tire sizes mixed together. 285 is the width of the tire in millimeters. 70 is the aspect ratio, which determines the height of the cross section by the width of the tire (70% of 285mm = height of the rubber above the wheel). A 285/70R17 will be about one inch taller than a 285/65R17, and they will both be about 11 inches wide. 295 is about 11.5 inches wide, and 305 is 12 inches, etc. An easy way to get around trying to figure out what tires will fit is to just get wheels with 4.5 inch back spacing.

BFGMallTerrains

I had 285 70 17 KM2's on my '13 auto JK and wanted a bit larger so went to KM2's in 305 70 17. Mounted as always on my stock 7.5 Rubi wheels the overall width is nearly identical, just a little wider, but an inch taller. With both I was and still am able to turn the steering wheel exactly 1.5 times before any possibility of rubbing up front and clears fine in the rear. Never used spacers. Tho the most treacherous terrain she encounters is the mall parking lot. And maybe a small pothole.

btadlock

I knew there was math involved, just did not know how wide the stock wheel and jeep could accommodate, buddy has 315/70X17 on his stock rims with spacers, as $$$ are an issue, just looking to see the largest, widest size w/o spaces, looks like in a later post, 305/70s may be the limit.
New wheels would be nice, but again, $$$ are a issue.
Thanks.

BFGMallTerrains

Yeah I was skeptical about 305 70's after reading all those "what largest tire fits" articles but found that the stock 7.5 Rubi rims squeeze em just enough that there's minimal difference in section width from my 285 70's. Decently better look tho, looks like a jeep should look without being uber huge