What is the widest low profile tire that will fit the rear of a 1969 Karmin Ghia on stock 5 1/2 inch smoothies?
Well this seems like an easy question, but it’s not. There are so many variables. Other items needed to know is: what is the offset of the wheel, What lower profile, 45,50,60,70 and so on, Is the car lowered, ect. Also the brand of tire will matter. I have take 5 tires of the same size, but different brands and formed a small staircase!
The rear of the Karman Ghia is tight, so tires can be a challenge. My best recommendation is to go to a local tire company and ask to set tires next to car. If you got a guy willing to help, have them pull one rear wheel and set the tire(unmounted) in the wheel well. With the jack, adjust the height of the car to simulate ride height.
If it is not possible to take the car, then mock it up. Take 2 strings and tie a weight to one end of each, a nut or washer will work. with the rear tire off, tape one string to the upper shock mount or what ever is the first thing on the car that the inside of tire will hit, with the other string, tape it to the inner wheel lip. Now you have one string to measure from the drum out and one string to measure from the drum in. Take a note pad and write these measurements down. Measure the back space of your wheel. With these measurements you can now calculate the maximum width that a tire can be to fit into your wheel well!
I hope this will help, Andy