I found some dunlops for only $412.00 a set. looking to increase ride comfort so really need to use 50-55 instead of 40 profile.

 

That will throw off your speedometer.

 

Do you realize that tire is almost 29" diameter, more than 3" larger than stock. You can't even fit it in the wheel openings (I know what I had to do to fit 28" slicks ). It would make your car pull like you swapped in much lower numerical gears. Car would ride 1.5" higher from the road than it is now. Would close up the gap between the tires and the fenders, though

Switching to moderator hat: Please post "tire" questions in "Wheels and Tires" forum.

 

no i did not know that, thats why i love these forums. what about 275/50/17???? I know the stock tire size is 245/50/16.

 

275/50-17 would still be too big... do they even make that size??? Its almost 28" diameter. You are looking at tires for SUV's, not for a sports type car.

You're going to have a problem "increasing the ride comfort" if you are running 17" wheels. You have to match the outside diameter of the stock tires (25.65") and that means you will have a shorter sidewall on a 17" wheel than you had with your 16" wheels/tires. The shorter sidewall rides harsher than a taller one.

The correct sizes would be 245/45-17, 275/40-17, 285/40-17 or 315/35-17. All of those are close to the stock tire diameter. What is the width of your 17" wheels?

Curious.... what don't you like about the way your car rides? Most people want to tighten up the handling, not make it ride like a Buick

 

I have 17"x9.5" rims. Looks like I am stuck with the 40. I have the BMR track pack (sub-frame conn./ s.t.b/panhard bar/ rear lower control arms...etc...)on my car so it is stiff as a board. great for racing but geeez, everytime I switch lanes and hit the city ******* my car really lets me know it. There must be something I can do to improve ride quality........any ideas???new shocks/springs????? replace bushings????? my car has 136k miles so Im sure the bushings ans shocks are not up to par.....

 

hee hee ... i like that!

 

With the 17x9.5" wheels, you need to stick with a 285/40 or a 275/40. Go to Tire Rack, and do a "search" by size. When you get all the tires that they have in that size, there should be a button that allows you to compare the "user survey" data for all those tires. One of the categories that they rate numerically, in order to rank the tires is "Ride Comfort" or something like that. It should steer you toward a tire that runs a little smoother than some of the others.

I know what you mean about ride quality..... I have the full complement of Spohn suspension pieces, all with rod-ends (including the rear sway bar), so the car it about as tight as it could possibly be when its rolling on street tires (275/40-17 BFG KDW's in the front and 315/35-17 BFG DR's in the back).

 

Any increase in tire size will. I upgraded from the stock salad shooters to 275/40/17 and now from 0 to 35-40ish my speedometer reads 5mph higher (Says 40 when I'm really only going 35), and when I hit 40+ reads 10mph faster than it really is (Reads 55 when I'm radared at 45).

 

Could get a more touring oriented instead of performance oriented tire.

 

not in the sizes that fit out vehicles

 

There's something wrong with your speedometer. Putting a LARGER diameter tire on the car than the PCM is calibrated for will make it indicate a speed SLOWER than you are actuall travelling. But you put a SMALLER tire on it.

If your V6 left the factory with "salad shooters" (RPO N96), it had 235/55-16 tires on it (RPO QMT). That tire is 26.18" diameter. A 275/45-17 is 25.66" diameter. That means the new tire is 2% smaller than the stock tire, and will cause the speedo to read 2% higher than actual speed. That would mean at a true 45mph, your speedo would be reading about 46mph. If its reading 55mph, its broken. Reading 55mph at a true 45mph (22.2% error) would require a tire diameter of 21"

 

GM did put 16's on f-bodies. If you don't like the ride of 17's, then there ya go.