I bought 14” pugs with 205/70R14 studded snows. They absolutely won’t clear the fender on my 85 BRAT (stock tire 185/70R13. I neither want to roll the fender edge nor add a lift kit. The “tire size calculator” http://www.miata.net/garage/tirecalc.html show a sidewall difference of +0.5” and a radius diff of +1.0 for these two. Now a 195/60R14 would have a near perfect fit sidewall diff of –0.5” and radius diff of 0”. QUESTION: Surely 185/70R14’s will clear at sidewall diff 0.0” and radius diff of +0.5”. Will pretty much any size tire with a radius diff of no more than +0.6” regardless of the sidewalls fit? And which size oversize tire would look the nicest on these pugs (and still fit my BRAT)? I’m talking year around non-snow tire.

You could just lift it a bit.

A 195/60r14 will work best IMHO.

True gives the same radius and 1/2" less width on the sidewall. But I am hoping that 185/70R14 will fit (gives same sidewall/width and 1/2" more of radius).

http://www.miata.net/garage/tirecalc.html

 

That is the best tool EVER when it comes to finding propper tire sizes. If your 205/70R14s rub, plug that in and figure out how low you'll have to go to get clearance.

 

Dont be affraid to buy a hammer and use it. These cars were never offered with anything larger than 13" from the factory... there was probably a reason for that.

I cannot think of a single reason a 185/70/14 will not fit without rubbing. I ran 195/75/14 on my 87 Brat and had to trim the inside of the front mud flaps. It would hit if turning and hitting a good size bump at the same time. After a little over half the tread was gone they never rubbed again. A 195/75 is about a full inch taller and probably the same width as a 185/70. The 185/70/14 would be a better choice as far as speedometer error and highway use. These little engines can sometimes struggle with the stock tires. I went back to a 185/80/13 and the stock rims. They are about the same height as the 185/70/14 and don't even come close to touching.