My '08 G35x sedan has 85,000 miles. Hated the OEM Eagle RSA's with their rough ride feeling every road imperfection and 2/32nd's tread at only 29k. Unlike many here, I like a more comfortable longer lasting grand touring over a high performance tire. Replaced the Eagles with Michelin Primacy MXM4's at 29k. With 56k on the Michelin's which I really like, I'm at 4/32nds and ready to replace soon. I had one replaced from smashing a curb and damaging the sidewall and that one has 7/32nds. I also have Kumho Solus TA 71's on my old Lexus RX300 (kid's car now) and they have been very good but of course the old Lexus is not driven the same way as I drive the Infiniti even if I'm not a boy racer.

Bottom line is I could but a whole new set of Kumho's from Tire Rack for $400 or 3 Michelin's for $518 but would have 3 with 10/32nds and 1 with 7/32nd's tread. Here are the specs. Suggestions/opinions between these 2 options would be appreciated or if you think there is a better grand touring selection. Thanks.

https://www.tirerack.com/tires/tires...m=255VR7TA71XL

https://www.tirerack.com/tires/tires...n&autoModClar=

 

First off, the Michelin will definitely be the better tire. Given your own description of you driving style, I highly doubt you would ever even notice any potential handling difference due to a mismatch in tread thicknesses. Now, with that being said, what does your current spare look like?

You could just put that 7/32 tire onto the spare and then buy a complete set. Buying a complete set of 4 Michelins allows you to use the $70 rebate that comes up every other quarter at Costco, America's Tire, Tire Rack, etc. The last promotion ended May 31st, which means the next one will undoubtedly begin at the end of August, so if you can sit tight until then, you can bring the cost differential down even further.

.02

 

Thanks VQ - actually I only have the donut and should have mentioned it. You are right about the rebate - perhaps the best idea is 4 Michelin's for the rebate and keep the used one as a spare. I'll think it over but thanks as always.

 

There's no doubt Michelin makes a better tire but I doubt they will change the ride quality you seem to be more concerned about! If you're currently running a 40 series tire by changing to a 45 series might help improve ride quality. Check with www.thetirerack.com and get their opinion. They sell tires at wholesale, prices your tire shop can't match!
Gary

 

Kumho is making some high quality tires, and those particular Grand Touring sets rate higher than the Michelins. The Kumho Tires that are stock on the Viper ACR were performing better than the best Michelins, so they have come a long way for sure.

That said, I think you've gotten sound advice, especially when you factor in the rebate, and Garys' reply about going to a bit more sidewall may also work well for your driving needs.

 

Ride harshness is a combination of several things, but the biggest is aspect ratio. A 50 or 60 aspect ratio tire will ride smooth as glass compared to a 35-40. Next is Spring rate, then comes tire stiffness. Run flat tires (no matter size) will ride harsher than conventional tires.