[beluga]

I have to say that one of my primary complaints with test n tune is when you purchase new tires. If you purchase the exact same brand of tires, your mph should not drop 7+ mph. It's incredibly frustrating to have to re - test n tune your car every time that you buy tires, even if they are of the exact same variety. If you keep the same tires, it shouldn't change your speed. When this happens, it makes it seem like tnt is just pure guess work and a way to waste credits.