Double check tire size before mounting

[Print Dad 58]

Hello All,

My first of 2 questions involves my recent purchase of tires.

I bought a set of 225/70/14 for our 70 Mach 1. I thought the car had 215/70/14 on it. Turns out they are 205/70/14. I don't know I screwed up.

 

I am pretty certain, the rear will be no problem and now I am worried about the front fitting. Perhaps I should have gone with 215/70/14 on the front. I don't want to mount them and then find I have a problem. I am thinking of mounting the 2 that will go on the rear and see how they fit n the front, then I could mount the other 2 and mount rear.

 

I think I'm OK but would feel better knowing. The rims are old Keystone Classics and I like the look. Couldn't go for new rims $$.

 

I would feel better if others gave me an idea. Some guys are running 245/60/16 tires but I am not certain how that relates to me. I guess I don't know too much on tires.

 

Thanks -- -Print Dad

[LoneWolf2U 136]

They sould fit fine without rubbing the fender lips.

I have 225/70/14 on the 68 and 225/60/14 on the front of the 70 Mach.

[foothilltom 33]

Hey PD, if you had 205/70/14's on the rear, your new 225/70/14's will be quite a bit "taller" than your old tires and will impact your speedo around 4.1%. 4.1% too slow, in fact. So just be aware when you're rolling around.

 

Tom

[Pakrat 1,043]

Yeah, should be no issue. My car had 225/70-14's on it all around for years with no issue, still technically rolling on them in fact in the garage.

 

If you can get past the fact that this calculator actually comes from a Miata website, it's very handy to visually see the difference in overall diameter of any wheel size and aspect ratio combination. Standard diameter goal for a Mustang is about 26" around.

 

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

 

As a reference the baseline tire size originall offered was 195/70/14 with an upgrade to 215/75-14 available. In the Shelby reference manuals the 225/70-14 is the maximum recommended size for a standard 14x6 ford wheel.

 

As far as your speedo, what you are replacing only matters if the speedo gear is based on your old tire. Your 205's were not stock so unless you changed gears when you put those on then it has likely been off ever since.

[ashleesmach1 28]

My 1969 mach1 has 235/60/R15 tire front and rear and They don't rub any where so you should be ok. Check this out:

 

1969 MUSTANG MACH 1 TIRE SIZE AND DIAMETER

25MM = 1 INCH APPROXIMATELY.

STOCK SIZE - P/195/70R/14.

195MM = 195MM DIVIDED BY 25MM = 7.8 INCHES TIRE WIDTH.

70 IS A PERCENTAGE OF THE TIRE WIDTH, SO 7.8 INCHES - 70% = 5.46 INCHES.

5.46 INCHES IS THE SIDE WALL OF THE TIRE OR HEIGHT OF THE TIRE FROM THE WHEEL LIP TO THE TOP OF THE TIRE.

14 = WHEEL SIZE FROM THE TOP TO THE BOTTOM OF WHEEL LIP.

OVERALL TIRE AND WHEEL DIAMETER IS 5.46" + 5.46" + 14" = 24.92 INCHES.

CURRENT SIZE - P/235/60HR/15.

9.4 INCHES - TIRE WIDTH.

5.64 INCHES - TIRE SIDE WALL HEIGHT.

15 INCHES - WHEEL SIZE.

OVERALL TIRE AND WHEEL DIAMETER IS 5.64" + 5.64" + 15" = 26.28 INCHES.

OPTIONAL TIRE SIZE - P225/60HR/15.

9 INCHES - TIRE WIDTH.

5.4 INCHES - TIRE SIDE WALL HEIGHT.

15 INCHES - WHEEL SIZE.

OVERALL TIRE AND WHEEL DIAMETER IS 5.4" + 5.4" + 15" = 25.8 INCHES.

[jjstang 51]

Not to hijack this thread, but....

 

if you wanted to run a 50 series tire, back spacing starts coming into play doesn't it?

What would be the stock backspaceing and what would you need to make a 50 fit, if it will? I was thinking something like a 235/50/15 on a 8" rim front and rear?????

[Print Dad 58]

Hello All,

Thanks so much - - I feel better. I don't know how I made a stupid mistake by thinking the tires on the car were 215 when they are 205/70/14.

 

I looked and there is room and I thought I was going from 215 to 225 not a huge difference.

Thanks to you people I feel much better.

 

Thanks so much to all the responders and for the insight and lessons.

 

I wish I had time to thank each one individually. But for NOw - - - THANKS people - - God Bless - -you helped a lot.

 

 

Print DAd

[jkskinsfan 19]

Hi Print Dad. I have a Tire Size chart from BF Goodrich for their Radial T/A's. According to their Chart, 205/70R14's on a 5 to 7 inch rim have a Diameter of 25.4 inches. These are what I have on the front of my '69. 225/70R14's on a 6 to 7.5 inch rim have a Diameter of 26.5 inches. Barely more than an inch taller. You shouldn't have any problems with them.

[Print Dad 58]

Hello jkskinsfan,

Thanks for the help. I just don't know how I do these stupid things.

I was pretty certain I had 215's on there.

I'm gonna mount 2 and try them on the front. If they rub, I'll move them to the back

and return to unmounted to Summit for a skinnier tire.

 

I just can't seem to catch a break here. I should know better - - measure twice - cut once. LOL - - Thanks again - - Print Dad