I'm running 245/45 R18 = Front Tires & 275/40 R18 = Rear Tires with 6.75 BS and I can not go any wider without wheelhouse mods done. Someday I'll trim the lip so I can go to a 295 possibly even a 315 series
Old school Buick 8 x 15 rims would be 4 1/2 buck spacing wouldn’t they? 40’s or 50’s would be a lower profile tire. I run 255/60/15’s on back now. Seems I would have plenty of room to run 275’s ??? How much wider is a 275 vs a 255? 1/2 inch?
Buick never made a 15 X 8” wheel, just a 15X 7”, and that would have 4 3/8” BS. 68-69 cars need more BS than the 70-72 cars. A 275 tire is 20 mm wider than a 255, that is close to an inch (25.4 mm). Lower profile tires have a shorter sidewall. The aspect ratio is the height of the sidewall compared to the section width, so a P275/50R-15 would have a sidewall that is 50% of the section width of 275 mm.
Larry, great information. I figure my rims were 8” not 7” wide. I like the 60 height, just want it wider.
Ok so 255s fit. Minor trimming on metal tabs but fit. I guess these American Racing Torque thrust II wheels have like 3 back space.
I hope I'm not to late for this conversation. I "thought" I read somebody wanted to hear from someone who is running 275 60 15 tires? I have three 68 / 69 cars and they all fit that tire on the Rally 15 inch wheel with no issues. I can send pics tomorrow in the daylight. You do have to jack up one side at a time to get them on though. I use 235 60 14s on the front. I haven't tried 15s on the front???
I know a 275 with theses wheels would not fit unless I trimmed inner fender. Back space isn't enough. The 235s seem good to go on front.
WB - i’d like to see pics if possible. I’ve read several older posts saying that you can slide 275/60/15’s under a ‘69. Larry mentions that it’s a 20mm difference between 255’s and 275’s or about an inch. I have 255/60’s on now and there looks to be plenty room both sides.
I have a 1972 Cutlass .. Ya I know not a Buick, Someone suggest I join you guys because of the information available. Question: I'm ordering some factory rally rims and would like to do 15 x 8, However I'm worried about rubbing, fitment etc. Currently running 245/60R14 on what I believe are 14x 7 (Hard to measure mounted on the car with tires) Also on a different note .. I can't find where I click to start a NEW Post. Can someone point me in the right direction ... Thanks Jeff PS. I do own a LaSabre and a Regal
