I keep reading questions from many members concerning the
widest tire they can put on their vettes. But I hear very little
concerning the width of the tire on the pavement. I have noticed
that there are several manufactures that make the tire foot print
larger than taller and wider caseings of other manufactures. In
other words the bigger tire does not mean the widest foot print.
Do other members think about the tire foot print on the pave ment
or is this something that I alone consider when buying tires.
Your coments please and thank you.

 

passenger tires sold in the US must meet D.O.T. standards. A tire size of P185/60R14 would mean "P" for passenger tire "185" is the width in millimeters the "60" is the aspect ratio, meaning it is 60% as tall as it is wide, the "R" after the 60 stands for radial construction, and the 14 means it will fit on a 14 inch wheel. All tires sold as passenger tires in the US must meet this D.O.T. standard. So all P185/60R14 are going to be the same width (185mm). There shouldn't be any variation is width (or sidewall height for that matter) in the same size tire. The tread patterns will vary, but the width of the tire is going to be the same for the same size.

 

The width of the tire is measured at the widest cross section, not the tread. A lot of manufactures will not list their tread width.

Tread Widths

Here are the widths from Tire Rack:
The OEM Goodyear runflats are EXTREMELY WIDE for their size. The tread width is even wider than the 295 Z06 tires, here are the specs (tread width)
-Goodyear F1 GS EMT (275) 10.3 inches
-Goodyear Z06 Tire (295) 10.2 inches
-Firestone (275) 8.6 inches
-Goodyear F1 GS D3 (275) 9.4 inches
-Goodyear F1 GS-2 EMT (285, 19 inch diameter,C6 tire) 9.2 inches

 

I never thought there could be that much difference in tread width.

 

The original OEM Goodyear Runflats have very square shoulders, hence the wide tread. That is one reason that they look so good on the car. Even though people don't believe it, the OEM Goodyear Runflats are one of the best handling tires (according to the magazine "Corvette Enthusiaic", they even handle better than Goodyear GS D3s).

 

I find that very, very hard to believe.

 

I can't compare the original runflats to Goodyear GS D3s but I can compare them to BF Goodrich
TA KDW's and I can tell you there IS no comparison. The BF Goodrich TA's are far superior in every catagory. Handling, Dry traction, Wet Traction, Ride and Quietness. I replaced my runflats with only 5000 miles on them with the BF Goodrich TA's and it is THE BEST thing I've ever done to this car.

 

FWIW, tread width is only one part of the equation. It is important but so is the inner design of the tire and the tire compound (softer tires have better adhension).

I find it very hard to believe that the runflats are better than a good after-market non-runflat tire. The stiff sidewall combined with the harder tire compound of the runflats hurt rather than help performance.

 

I found this out as well.. I had 305/30/19 Pirellis on my car and then I bought my new set of 305/30/19 Yokohamas they measured 1/2' wider.

The reason as mentioned before is the actual "section width" may differ. The Pirellis are a little more rounded on the top where the yokohamas are more squared.

 

Here is a pic of my example above. These are both 305's

 

Which model Yokohama's are those that you bought, and what sizes?

 

Have a look at Hib Halverson's review of the GSD3 before believing the EMT's handle better.

 

I just went through the tire dilemma twice. My wife drives an Acura TL with Michelin OEM tires. At 70K miles they were worn out, erratic, and very noisy. After considerable debate I went ahead and replaced them with the identical ($200 each) OEM tires. The difference was night and day. It is like a new car. New tires were quiet, smooth and not noisy at all. Handling was much improved.

Now on to my 02 Vert: Had OEM runflats. I had the same issues as the TL, noisy, rough, followed every groove in the road. I had decided to go with an alternate tire. Then I thought about my experience with the TL. I thought about the security of a run flat. I do like the size of the GY RF. From what I can figure, GY RF has the widest tread of all stock sized tires. Yesterday, I bit the bullet and had all 4 replaced with GY RFs. It is amazing, but the car rides like a new car. It is much quieter, much smoother, and does not grab every groove in the road. Moral of the story is that there is a huge difference between 8 year old dried out, worn out tires and new tires of the same brand and model. Yes, they were expensive and they are not necessarily appropriate for everyone. If you are on the fence and hesitating because of noise, harshness, and poor handling, you may want to reconsider.

 

I reluctantly switched my Goodyear OEMs out for Michelin RFs. There are only two drawbacks to OEMs that I can see (based on experience) One: the GY EMTs wear out pretty quickly when used on a daily driven C5, which exacerbates the added expense of buying them. Two: the OEMs are quite hard to find in a lot of locales. The Goodyear dealers in most places just don't seem to keep them in stock. If the dealers in Killeen/Fort Hood/Copperas Cove had them in stock I would have just replaced my worn out front tires with OEMs. FWIW, I am happy with the Michelins (I've even gotten used to the look) but the above is VERY much the truth