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66 Cutlass-Looking for tire sizes on the rear.
I want to fill them up pretty good. Huge wheelwells on the car. Closest thing I can find is a 325/50/15 tire. Dia is 28" width overall is 12.400 with 11" tread. Has anyone tried a tire this large. It fills wheelwell good, maybe too good. Thanks
The 325/50/15 are expensive and are mostly available as a DOT tire or a drag radial not recommended for the street. The 275/60/15 is what most use on a 67.
275/60/15 on the rear, 235/60/15 on the front. If I had 3-4 people in the car the fronts would scrape turning a sharp corner. The front had 1 inch drop springs..
275/60/15 on the rear, 235/60/15 on the front. If I had 3-4 people in the car the fronts would scrape turning a sharp corner. The front had 1 inch drop springs..
I'm going to go out on a limb here and suggest that the reason your tires scraped is because of the offset on those Cragars, not because of the size of the tires. Those are NOT zero offset wheels.
Test fit N50 15s once on a 67 i had about 22 years back. Loved the look of the tire by itself but they looked too big on the car. Couple of years later bought 275 50 15s for my then 66 442. They fit great, and were mounted on the same exact Centerline rims as the 67. They looked great on the car but actually slowed the car down to the point that it was quite noticeable. In any case that size does not seem to exist today, in an all season radial.
275 60 15s weigh about 15 lbs more per tire than the factory spec upsized 15 inch radial equivalent for a 66 Cutlass. The unsprung impact from that is tremendous. Like putting 240 lbs of weight in the trunk. Then there is the increased rolling resistance from the longer contact patch due to the taller tire. Last but not least the extra 2.5 inches in diameter reduces the effectiveness of the rear gear. If factory correct was 3.08 now effectively it will be 2.80 . The car will feel sluggish unless the engine is so powerful that it requires that size tire for reasonable traction. Of course none of that matters if looks are the only priority.
275 60 15s weigh about 15 lbs more per tire than the factory spec upsized 15 inch radial equivalent for a 66 Cutlass.
Sorry this one jumped out at me since I'm swapping from BFG Radial TA 275/60/15s to Nitto 555RII drag radials 275/60/15s on my 70 Supreme. The BFGs weigh 36lbs and the Nittos are 30.42 lbs. Crazy to see that much of a difference between brands although maybe the drag radials are lighter because of the different compound?? Anyway just throwing that out since I had actual weights for both. If the factory spec 15 inch radial is only 15 to 20 lbs total, that's an extremely light tire - just say'n.
I bought new 1 inch drop springs-I think that could have been a factor. Yes the offset on the Cragars was stock . Somebody on here got a hold of me years ago and saw this car in a salvage yard because the new owner totaled it. He was also parallelized. That made me sad...
I run 275/60/15 on the rear for daily driving. For "playing", I bolt on the 325/50/15 Nitto's. Tread with is over 12" (12,4").
As far as taller front tires, they do cover the staging lights a little longer. As far as rolling resistance, the taller tire increases the leverage to overcome wheel bearing friction. Drag racers discovered all this way back in the 1960's. They also used taller tires with the smallest tread width.
2012 Camaro rims and tires fill the wheel openings pretty well. 245/45R20 front and 275/40R20 rear. They did require 1inch spacers/adaptors to convert from 5X4.75 to 120mm bolt pattern. This also keeps the fronts from rubbing against the frame at full turn. The spacers did need minor adjusting of the hub sizes on my mini-lathe to actually fit. Mine is the ugly one in the front...
They are not any less reliable than a properly torqued wheel and the 1 inch will not put any more stress on the hubs than a wheel with a one inch offset. I'll risk it for the results.
Every one ton dually truck left the factory with 6.5" wheel spacers on the front hubs.
The issue isn't the spacer (assuming a properly-designed, hub-centric spacer). The issue is that the tire contact patch must be centered under the wheel bearings so there is no bending load imparted. I'm guessing that these wheels have significant positive offset. If so, spacers would put the tires where they belong.
