Hi Folks,
I have a full set of the 15" Olds SS II wheels with the bolt on center caps on my 70' 442 at the moment. The tires on the back never seem to hook that well & plant the way I would like them to. I am thinking of trying a pair of the Mickey Thompson Street radials or perhaps the M & H variety. My question is...."what is the maximum tire size I could comfortably put on these older SS II 15" wheels?"
All responses / ideas are appreciated. Thanks.
Brad

 

How wide are they?

 

I would say you can get P275-60's on there with no problem.

 

The rims are 15 x 7's

 

255/60 work well but I have seen some folks push it to 275/60.

FYI I have 255/60s on the front but they rub occasionally

 

I have 255/60's on the back of my Delta right now, but they are 15x8.

The SSII I just picked up from another member have 255/60's on them and they look pretty good

 

Thanks for the help Guys! If I can fit the 275/60-15's on the back of my car mounted on these old 15" SS II's that would look fantastic. I will try taking some measurements this weekend before I buy the tires as I have 235's on the back right now. Hopefully 275's will fit as I really don't want to take my Sawzall to the inner fender well areas!
Brad

 

275/60/15 thread


https://classicoldsmobile.com/forums...5x10-rims.html

mickey thompson recommends 7.5 is minimum bead width for 275/60 tire.

 

Yes you are right- I noticed that on the Summit Racing web page as well. I wonder if a 1/2" difference will really matter? Is it potentially dangerous to put this tire on a rim that is only 7" wide instead of 7.5"??
B.

 

It'll certainly perform less than optimally.

 

275 x 60 x 15 BFG T/As fit good on my 67 mounted on 8" rims --- I think they would fit on 7s without any issue? You may not like the "baloon" effect on the sidewall though?

 

I run 295/45 on mine...

 

295's in the back of your car? Wow....do you have any pics to share of what it looks like? 👀

 

Chesrown I love the great shot of that 67' charging down the track with the elevated nose!! 👍

 

You "can" mount outside of the recommended rim width, but you WILL put extra stresses on the sidewalls and the contact patch will not sit on the ground properly.
I would stick with a 255/60/15 on the 7" wide wheel for safety and optimum tire performance.
If you jump up to an 8" or 8½" wide wheel, then by all means use the 275/60/15 as that will definitely give you a larger contact patch.
I use to sell tires and had many classes on the construction of them and why they had the specs they do. That is one reason I CRINGE at these IDIOTS that put the low profile narrow tires on WIDE rims. That is soooooo unsafe I can't even tell you....but that's for another thread....I digress.

 

Gimme a second, I'll post 'em this afternoon. It's on a '77 with a factory rear end, and the brake hat/wheel spacer are the same dimension as having the drum on there. Plenty of room for flex at the frame, I'll get pics of the gap, too

 

Wait, I lied, 295/50/15. I tried to get in the fame as much as possible so you can see at least an inch of gap between the rail and the tire. I don't have any body mounts on it, so there is still plenty of up and down travel for the suspension so you don't have to roll the inner lip of the fender.

 

I tried an old N50 15 M/T tire on my 77 Cutlass but it was on a 10" wide rim but I had clearance but I would probably roll the outer lip up for just a little more. And I have to say it looked real nice filling in the wheelwell.