V-EIGHT

I need a P275-50R16 tire that hooks good on the street and at untreated tracks, is decent for freeway driving, and dosent cost more than like $125 each. This is my first time having to pick good tires out. I hear a lot about BFG's.

Injuneer

A search on Tire Rack doesn't show up any 275/50-16 tires. That size would be about 1.3" larger in diameter than your stock tire size (assuming you started with the Z-rated 245/50-16 upgrade), and would throw off your speedo and hurt your acceleration like using a lower numerical (~ 3.08) gear ratio.

You would want a 275/45-16 to stay closer to the stock tire diameter. Even in that size, the only thing Tire Rack carries is "competition" tires.... soft compound, shallow tread depth tires for road racing and Auto-X.

I think BFG used to make a 275 width 16" tire in their "Radial T/A" line, but that's an all-weather, medium performance tire line.

You might consider picking up a 255/50-16 (BFG or M/T) or 245/50-16 (Nitto) drag radial and taking it easy in the wet, and recognizing that tread life will be poor.

V-EIGHT

I thought the P### was the width of the tire, and wouldnt effect the speedo or acceleration. So I figured going from a P245/50R16 to a P275/50R16 was just widening the tire and improving traction. I can have the speedo recalibtrated when I get it dyno tuned, but I dont want to hurt acceleration. I already need more gearing as it is

Injuneer

Yes... 275 is the (section) width of the tire in millimeters. But the next number "50" is the (aspect) ratio of the sidewall height to the width of the tire - think of it as a percentage. If you keep the aspect ratio the same (50), and increase the width, the sidewall height increases, hence the outside diameter of the tire increases.

245/60-16:

245/25.4 = 9.65" section width

0.50 X 9.65 = 4.82" sidewall height

16 + (2 x 4.82) = 25.65" tire diameter

275/50-16:

275/25.4 = 10.83" section width

0.50 X 10.83 = 5.41" sidewall height

16 + (2 x 5.41) = 26.83" tire diameter

275/45-16:

275/25.4 = 10.83" section width

0.45 X 10.83 = 4.87" sidewall height

16 + (2 x 4.87) = 25.74" tire diameter

V-EIGHT

After driving it some today I think the speedo is already off. I think it says Im going faster than I actually am. So a P275/45R16 would be about equivalent to stock tire height?

Injuneer

Yes, but only if your car came from the factory with the 245/50-16 Z-rated tire option (25.65"). The "base" Z28 had a 235/55-16 all weather tire (26.18").

V-EIGHT

Alright, so what tires hook good on the street and at untreated tracks, and are good for highway driving?