Tire Sizes

[Joe Kriston]

Any good tire guys out there?...I'm getting confused talking to the local Discount tire and Firestone dealers....I've got a set of four of these Keystone classics,appearing to be 8" wide,mounted on 205 75R 15's,which seem to be too small a tire for my truck....I want to use all four of these rims for my new tires,but I want go with that '70's bigger/wider tire in the back than in the front look....Any suggestions on the widest/tallest tires I can go with on these rims (for the rear only)?....Thanks....

[4x4_Welder]

You didn't get those rims from a Mustang, did you? Looks exactly like what I had on a '72 notchback when I was in Phoenix.
At any rate, I had 275/60/15 Hoosier GTs on the 8" Keystones, and they fit nicely. I know that size will fit in the wheelwell of these trucks, too, I have 285/75/16s on my truck now.

[Joe Kriston]

Thanks,Jared...No,I did have a '67 Mustang coupe,but these wheels came with the '54 F100 I bought a couple of years ago...My truck already sits high in the ass-end because the p.o. put overload camper springs on it,so clearance will be no problem...I just want to go with that '70's look,where you jacked the rear-end up,put big tires on the back and fish-tailed all over the place when you stomped on the gas---provided,of course,one could afford to have a little gas in the carb to stomp on...

[Aubrey]

I had a good tire man tell me the tire tread should be no more then 3 inches wider than the rim. I don't know how true this is, but I just wanted to get my in.

[bleedfordblue]

A 275/60/15 is about as wide as you can go with 8 inch rims and get any kind of tire wear. That's what I have on mine, and they look relatively large on there. BTW Jeg's has new Keystones for sale, so if you want, you could order some 15x10's to go on the back and get really tire crazy.

ggod luck
Scott

[jzjames]

Hey. Anybody got any pics of those 275/60/15's on the back?

[pat67shorty]

275/60/15 rear and 235/60/15 front would be a nice como with 8" rims...

[xxxtina63]

I have run 295/50-15's on 15x8 rims in the past and have never had any complaints or problems. This is supposed to be the widest tire you can run on an 8 inch rim, with a 10 inch rim recommended. One thing to be aware of, this combo creates serious sidewall bulge. If you scrape a curb or something, the fun may be over for the tire.

[Joe Kriston]

Thanks for all the replies...I have to admit,driving a longbed in city traffic,where you have to make a sharp right to try and sneak into traffic,I've hit my share of curbs...I don't know if I want to go 10" wides,Scott,....then I'd have to boost horsepower to justify them ....I think I might go with Pat's suggestion...I'd also like to see a pic,but I may just go to a dealer with those sizes in hand...When I went to one dealer,he kinda confused me,because the widest tire he had for the back was also a lower profile than the one he suggested for the front ...

Two more questions....Anybody know who would make those tires in a white letter?...And,...could somebody explain the formula or ratio that determines tire sizes?...I know it has something to do with the percentage of width x height,or something like that....Thanks again....

[xxxtina63]

OK, Pat suggested a 275/60-15. The 275 is the tire width in millimeters. 60 is the aspect ratio or sidewall height, which is 60% of 275mm. 15 of course is wheel diameter. If you want to convert the numbers to inches remember, 10mm=1cm, 2.54cm=1inch.

275mm/10=27.5cm
27.5cm/2.54=10.82inches wide

275mm x 60%=165mm
165mm/10=16.5cm
16.5cm/2.54=6.49 inch tall sidewall

[swissranger]

Ahhhh..nice to see some metric measurements.... , Normally I have to calculate inches to mm.

Roman

[stockr]

275/60/15 should do the trick...nice wheels by the way...they look similar to the mach 1 wheel....sweet

[Joe Kriston]

Thank you,Stockr....

xxxtina....I tip my glass to you.....

Roman,so then how do you convert dollars to kronas?....

[swissranger]

One dollar is about 1.22 Swiss Francs, not bad to buy nice Ford parts now

Roman

[bleedfordblue]

what's it like in switzerland this time of year?