Using this tire size comparer
I found that a
225/60-16 is 26.62" overall diameter and 8.85" section width with a 6 - 9" rim allowed. Section width would vary with rim width.
235/55-16 is 26.17" overall diameter and 9.25" section width with a 6.5-8.5" rim allowed. Section width would vary with rim width.
That's a 1.727% change, the shorter 235/55-16 spinning 794.8 revs per mile while the taller 225/60-16 spins only 781.3 revs per mile.
If the car's speedometer is dead on accurate at 60 mph with stock size 225/60-16 tires, it'll have to read 61.03 mph (call it 61
) with the shorter 235/55-16s to travel down the road at a true speed of 60 mph.
Your talking about less than 1/2 inch (0.45 inch
) reduction in overall diameter. Put another way, the 235/55-16 tires start out with new tread at near the same overall diameter as the 225/60-16s will be when nearly worn out.
Taller tires look better in these fenders IMHO. The 225/60-16 is an easier size to find
if traveling and you suffer a blowout and find you need to purchase one.
The slightly narrower tread of the 225/60-16 will likely be a hair less suceptable to hydroplaning in heavy rains than a wider 235/55-16 tire.
The narrower tire's tread being narrower, will suffer slightly less wear from scuffing in tight parking lot turns and day to day driving, all else being equal.
But, the diameter is nearly the same, and the wider 235/55-16 tire would look great on the Tbird.
If just a play car or strictly local driver, I might go with the wider 235/55-16 tire
especially if I had just finished 51,000 miles
on a set.
Knowing that I may take it on a trip, etc, I myself, would probably go with the slightly narrower and taller 225/60-16 tire
probably, if for no other reason but that it's more common and easier to find if on a trip.
Clear as mud huh?