What is a diameter?

Stupid question but i don't know the answer to. Let's say i have a stock tire on the camaro with 245/50/16 and i go with 275/30/19 (Rears) Does that mean my car will sit stock height or will it look like a 4x4? Now, can i go with different size tire if i want my car to look lowered?

Your 245/50-16 has a diameter of 25.65". That means that one radius of the tire (= diameter/2) is the distance between the road surface and the centerline of your axle. A 275/30-19 is a 25.50" diameter tire, so its smaller than the stock tire, and would lower your car less than 1/10th" (not noticable). It will also open up the gap between the top of the tire and the edge of the fender opening by the same amount. You might want to consider a 285/30-19 (25.74"), which would be closer to your stock tire diameter.

Changing tire diameter is not a good way to make your car "look lowered". Going to a much smaller diameter tire would lower the chassis relative to the ground, but it also opens up the gap between the top of the tire and the fender, and that's already way too large on stock ride-height cars. You also screw up your speedo, increase tire wear rates and may alter handling characteristics. The smaller tire sidewall hurts straight line acceleration, makes the ride much harsher and leave the wheels more susceptible to damage from potholes.

so with 275/30/19 am i really safe if i go over potholes or big bumps? How much sidewall will i really have? 3 inches?

3.2" of sidewall. I wouldn't go any smaller. Dodge the potholes if you can, and go slow over speed bumps.

Sweet:: Thanks :cool: