Originally Posted By: johnsmellsalot
When I first read the title, I thought the OP was joking. You can't get a soft ride with 45s. Low profile tires are popular for they're better handling, cornering, and steering response.
Depending on sidewall construction and design, some low profile tires are a little softer running than others. But everything else being equal, it is usually harder to get the same comfort level with a lower profile tire than with others. So I agree with you in the abstract. A 75 series should be more comfortable than a 35.
But cars that are well-designed for low profile tires tune the suspension elsewhere to accommodate them. Spring rates, shock/strut tuning, and even bushing compliance, all play a part in damping impacts before they reach the chassis. The 35s on the back of our SL ride more comfortably than the 60s on our other car because of that overall excellent suspension engineering.
Conversely, if I dial in the "advanced" track suspension setting on our R, it had better be on a glass smooth roadway, as you can feel the specks of dust on it. That's the price for no-compromise grip and response.