Yet another tire size question...

…or two

So it’s time for a new set of tires for the Coug. (68)

Cut to the chase: Anyone running 235/70-15s on the back and/or 215/65-15s on the front?
Got pix of a '68 w those sizes?

Here’s why:

On the car now: 235/60-15 back, 215/60-15 front.

Front story:
I’ve never been too happy with the looks of the 215/60s on front - they don’t fill the fender wells very well. (Car is lowered in front.)
I recently shredded one of the fronts, and put on the spare which is on an original 14" rim -with a 215/70-14 tire.
I think it looks pretty good/right. So found a tire height calculator, and it looks like a 215/65-15 is nearly the same height as
the 215/70-14

“Back” story:
235/60s look good. Like the width - doesn’t protrude. Could use a little more height. Thinking 235/70s - about 2" taller than
a 60 series - only 1" more radius.

Thoughts? Pix? Thanks!

There are no issues with 225 60 15 fronts. No one really runs 70 series tires anymore. Most of the guys with Mustangs when they are trying to stay more in tune with the factory sizes may. You’re effectively reducing the gear ratio with a 235 70 15. The tire is two inches taller and five inches different in circumference. This will also facilitate a need for a speedometer gear change. Factory tire sizes are about 27" in height. A 225/235 width tire looks much more aggressive and there are benefits to having more tire on the ground.
I am running 17’s, primarily because of lack of good performance tire choices for the 15" rim. 245 45 17 fronts and 255 45 17 rears. No issues with clearances. There are pictures of my Shelby and there s not a large amount of open fender well. Good tire shops with often mount a tire for you if they have them in stock. Often it just depends where you choose to purchase tires.

Your correct about height. Instead of 14” skinnies on my 62 Biscayne, I wanted bigger brakes, so to hide them but still have stock looking tires, a 215 65 15 is perfect. Could be a little wider if you want more tire, maybe a 225, but would probably look just right. Getting up to a 235 is basically a 9 inch wide tire. And, I paid about $60 per tire…so I can smoke them without breaking the bank.

I ran 235/60R15’s on my car originally (because the previous owner put them on) but I always had trouble with them rubbing on the outside when I hit bumps. Making 'em 70 series would only aggravate the situation. To be fair, this was with a set of 70s ‘turbine’ hurricane style wheels. I don’t know what their spacing was. Maybe with different backspacing you could bring them in, but then you’re in danger of rubbing the inside on fenders or leaf springs. I suppose it depends on how aggressively you turn corners, and whether the roads you’re on are smooth.

Mustang and Cougar fender openings are different. The back doesn’t seem to be an issue but the front is a little tighter. Inside clearance is the same. Tires vary some from brand to brand so you might want to check with the tire manufacturer for exact height specs.

If you can hold off for some time, I believe WCCC will have a tire/wheel measure gauge that will help these situations.

I have 235/60/15 rear and 215/60/15 front. I too don’t care for the look up front. I have been wanting to go up in size in front also…I thought about swapping front and back just to see if the 235’s would actually work up front and maybe go up to 255 in rear. I remember back when my '68 was my daily driver with the 14" wheels there were times that I went a bit too tall (even though skinny) on the fronts and they would occasionally rub (and of course tear the hell out of wheel lip trim) has all the specs of the different brands of tires. Go to the tire you want and click on the Specs tab…

here is another good link I use

it will compare Diameter, Width, Sidewall, Circum., Revs/Mile on any size 2 tires side by side

it will also compare wheel offsets

I used this site pretty heavy while deciding on tires, works very well.

Speed shops like Summit sell tire and wheel fitment tools as well. The nice ones can cost a tad much for a limited use too but maybe have a couple people go in on one.