Slimpikins5

My 2010 Grand Sport finally needed tires on the front. I have 16,000 miles on it and had no idea the tires were shot as from the outside walk around they looked fine. My dealer changed my oil a few weeks ago and told me the inside edges were cupped badly.

I was very pleased to hear this as I hate the Goodyear Super Car tires; they are harsh to ride on and horrible in terms of noise level. This pushed me to research tires options and my conclusion was that the newer Michelin Pilot Super Sport, NON-Run flat was the best option in that they are said to handle better than the Run Flat's and to ride smoother and quieter.

From there I started to shop for my best deal and was able to get the local discount tire dealer to beat the online retailer pricing however the hitch was that he would not sell me only two tires for the front, his policy is to never mount non-run flats on one end mixed with run flats as it was completely against all safety requirements and very dangerous in terms of handling characteristics.

I visited my local Chevy dealer who has a top notch Corvette mechanic who I know and trust implicitly. I spoke with this gent at length and he told me not to pay any attention to what the tire retailers say, he's mounted the mixed types before and its not an issue. So my Chevy dealer matched the lowest price I was quoted by the discounters and ordered me in the new Super Sports for the front.

I had them mounted along with a "modified" alignment specification which the mechanic suggested vs. the factory settings which entailed a much reduced camber degree setting to run the tires near the flat condition vs. a heavy negative setting. This reduces the wear on the inside edges of the tires (when we removed the tires from the car, my inside edges were worn to the steel belts!!!). One could not see this excessive wear without getting under the car or removing the tires.

I drove home tonight doing various roads from sharp on ramps up onto the interstate, straight interstate driving averaging 65 mph with some lane changes, a quick run up to 80, then some secondary 50 mph roads with nice turns.

The car is super quiet with the exception of the rear Goodyear's which are still noisy, however the front tires were what caused most of my noise. The ride is noticeably smoother and quieter, not to mention the handling is vastly superior to the car with Goodyear run flats all around! Lane changes are very crisp, smooth, not grabby like the Goodyears were. There is absolutely no unpredictable feeling as was asserted by all the tires dealers would be the case. My mechanic was 100 percent on the mark. Not to mention his 'modified' alignment settings have no ill effect on normal street driving. He said I'd only see the difference if I was tracking the car or really pushing the limits. For true street driving it would be a better setting as it will lead to much less tire wear and potentially better fuel economy due to the lower rolling resistance with his toe adjustments.

I cannot comment on how the car would handle with run flats on the front and non run flats on the rear as I didn't do this mix, however this combination is no problem at all. Can't wait for the rears to wear out so I can put on the Michelin Super Sports.

EDinPA

If that same dealer were to take your car as a trade in and wanted to sell it as a GM certified used car they could not do it with the mixed set of tires. They would pick the 2 tires that would cost them the least amount and swap them out to make a matched set.

CaryBob

There are several other threads on this same issue, and others who have put non-runflats on the fronts clearly agree with you.

BWF07

I have heard both sides of this story. Most (not meaning tire dealers) say that mixing different brands of tires is not a good idea. In normal driving conditions you will never notice it, but if you should get into a situation where you need to make some fast corrections or in wet condition you may see a difference. I have the GY runflats and I am just over 14K and will be changing mine, but it is my rear tires that need replacing as the fronts are still in good shape, but I will change all 4 when the time comes.

Slimpikins5

That may be the case, but I am not trading the car in. I simply had two worn out front tires and needed to replace them. I didn't want to replace them with Goodyear run flats to match the rears which are still OK. I want to switch over to Michelin now and finish out the tread on the rears. I did the mix so that I didn't get sold into buying run flats for the front.

Stockcar Axeman

I had the same situation as you did at 14K on my 07 coupe. I replaced with Michelin AS (I live in the Pacific NW) on the front only. Discount tires did it and they had no problem with putting on the non-RF on the front with the stock GY out back. I then put 20K+ the car and traded it in on a new GS. Never once did the dealer say anything about it being a problem with the miss matched tires. The car drove much better with the Michelins and I was looking forward to seeing how much better it was going to be with the rears done but I never made it to that point. I had the alignment checked out when I bought the car so hopefully the tires will wear evenly. Now I'm looking forward to replacing the tires with Michelin SS when the time comes. This time I'll do all 4 as I want to see/feel the total improvement all at once.

EDinPA

I understand. I had the same issue with my fronts but my backs were just about gone too. I went with 4 Bridgestone run flats and a much less aggressive alignment. I can report the same improvements in driving plus 10x better traction especially when the tires are cold or it is wet out. I think the alignment is the key. You will be just as happy again when your rears are ready for the next set.

Slimpikins5

All I can say is that there is a huge improvement from what I noticed in 20 miles of driving. And this was with mismatched tires. The Michelin's are also warranted for 30K miles which is twice as long as I got out of the Goodyear's. I probably have another few thousand miles left on the rears, which will be most of this summer. I'll put on the Michelin's in the fall and replace a faulty tire pressure monitor at the same time. My right front monitor was replaced today.