Maximum tire width/height

[wkrtsm]

I need to get a new set of 4 tires for my '68. The current size is P205-R60-15, so they are 205 mm wide, and 0.6 x 205 mm high.

Can I go wider to 225 mm or more? What is the widest you can safely go in a 912 without rubbing on the front fender during a hard turn?

I was also considering maybe going to a higher height like 65 or 70, to keep engine RPMs down on the freeway.

What do you recommend regarding max width and the rule-of-thumb for height.

(fyi - i think there was a post on PCA where someone said they had height of 65 or 70 and it felt weird when driving).

[racer]

the issue will be rubbing on the rear. Narrow rear fenders on the early cars.. 225 will likely be too large and rub (assuming you don't have flares). Can you fit your fingers between the fender and the tire currently with the 205 on the rear?

The usual caveats apply:
1) Ride height
2) alignment (negative camber)
3) tire size (not all tires are the same size despite the same number. Some 225's are a bit wider, some a bit narrower)
4) Rims being used.. and therefore factory offset or other?
5) spring/torsion bar rate
etc etc.

[wkrtsm]

There's about 1.5" between the tire and the rear and front fender.

Front:



Rear:

[wkrtsm]

I'll probably stay with 205-60.

[WFBowen]

Original tire diameter is right around 25.3inches (165/80 15 and 185/70 15.) A lower profile tire can result in a lot of daylight in the wheel wells. Any tire that is near this diameter and still has clearance with the fender would be a good choice. Check out a 205/65 15 as it's pretty much the correct diameter.