95jersey

I have been running Hoosiers for the past 3 years as for a long time, they were the only tire available in OEM C6Z sizes. I use to go back and forth between Hoosier and Kuhmo when running my C5.

Recently the 710 became available in C6Z sizes and since it has been so long and they have changed the compound recently, I wanted to see how everyone felt about the 710 as compared to the R6.

Here is some data I found on both tires.

Hoosier weight section width tread width

285/18 24lbs 11.5 10.9
345/19 30lbs 14.1 13.0

Kuhmo weight section width tread width

285/18 23.7 11.4 11.1
335/19 26.7 13.5 13.2

Now in looking at the data, it seems since the Kuhmo has rounded shoulders, while the section width is smaller, the tread width is larger. Also, in speaking with the Hoosier tire rep, he stated that for a tire to be labled a 345, it only needs to fall into a specific range to obtian that rating and there are cases where a 335 can be the same size or larger than a 345. Point in case,the Hoosier 285 is actually wider than the 295. So this makes things difficult as we can simply not just go by industry ratings, but you should look at the actual measurements of the respective tire vs. just beleiving it's rating

I have heard the 710 had a compound change recently.

I love the R6, but I am always looking at other options. From my recollection of the 710, it was equal/close in grip, but lasted quite a bit longer than the R6. It is also slightly cheaper than the R6. What is everyone seeing in comparing the 2 tires from a grip and longevity perspective?

Sidney004

Are your Hoosiers wearing out at the edges of the corner(or thereabouts) or evenly across the thread?

drivinhard

yep. Their (hoosier) 255 has the same tread width (and .1" wider section width) as their 275 (in 18" sizes) to.

95jersey

The rears wear great, but I have very aggressive camber and toe on my car, so I actually see the insides wear before the outsides cord. I know Kuhmo's are better for camber challenged cars, but mine is not one of them. I am strictly talking about performance and longevity given that you have the appropriate amount of camber for the respective tire.

BFoster

When on my C5 Z06-

Both tires were very close as far as performance, but I personally preferred the Kumhos.

I liked how the R6 had a quicker turn-in than the 710s, and how they worked a little better in the heat than the 710s without getting greasy.

On the negative side, they didn't last as long, and they weren't much good IMO in the cold. I also noticed that I wasn't wearing the tire down equally, could've been a camber issue, but doubtful since nothing changed on the car between the R6 and 710 switch.

There were three distinct reasons I liked the 710 better:

1. Iowa has some cool autocross days, and since the 710 worked better in the cold it was a natural pick. When it got hot, a spray bottle worked for keeping the tires cool between runs.

2. The price. Kumhos were cheaper than the Hoosiers last time I looked.

3. Here was the biggest point for me. The Kumhos would tell you when they were at the limit. You could feel it in the seat of your pants when the tires were just starting to lose adhesion. You would have the choice of dirt-tracking, or easy back on the go pedal to get more turn. I was very comfortable driving the car on the edge with the Kumhos. I can't say I was as comfortable on the Hoosiers, there was either grip, or spin.

Like I said though, this was on my C5 Z06, and this is a couple of seasons of running sets of 710s, and one set of the Hoosiers.

Hope this helps! I'll be interested to see your results if you try the Kumhos. I will soon be in the market for a C6 Z, so I'll need to know which tires to choose!

95jersey

Also, the more rubber the better and it looks like the Kuhmo is putting more rubber to the ground vs. the Hoosier. I think I do remember the 710 getting greasy on hot days, but I think lowering the pressure seem to help that a lot (if I remember correctly). R compounds in C6Z sizes go for $1440 brand new without any heat cycling, so it is important to weight all your options carefully.

Jason

Kubs

I will be trying out the 710s for the first time this year. I dont have much time in R compound tires but I was not particularly happy with my first set of A6s.

BFoster

Lowering tire pressure will help a bit, but it also made the car feel like it was rolling over the tires more. The sprayer is kind of a pain in the rear to bring to the track unless you trailer though. It's great to have, but a nuisance at the same time!

Either way, I don't think you can go wrong with the Kumhos. I know of a few racers in my region who ran on the R6's had issues with the shoulders of the tires cording quickly, even with significant camber. Could have a bit to do with caster setting, but I think I remember 3 different cars with this issue. It was bad enough that 2 went back to street tires!

gonzalezfj

My partner in crime, Steve Landstra and I have used both Kuhmos and Hoosiers extensively. We now use Hoosiers exclusively: R6s if you want longer life at the expense of some grip; A6s if you want maximum grip at the expense of some faster wear.

I didn't like the way the Kumhos felt. They don't turn in as crisply as the Hoosiers and they do turn greasy when hot.

I've never had a Hoosier turn greasy--even A6s in hot Georgia weather--in a typical 20-minute HPDE session.

As has been pointed out, Hoosiers need negative camber, lots of it. Hoosier recommends -2 to -3 degrees. Both Steve and I are running -2.7 with excellent results in our C6Zs.

We also reverse the tires on the rim (whether Hoosiers or Kumhos) at about half life to increase overall longevity.

Finally, if you look at the T-1 competitors at the SCCA National level, practically all of them are running A6s. You need to ask yourself why. The answer is that A6s are faster. Period. The few racers on Kumhos are mostly using free tires (sponsored by Kumho).

YMMV.

Frank Gonzalez

95jersey

Thanks for the feedback Frank, I am running -3.0, so I also don't see camber being an issue. I am not necessarily interested in being the absolute fastest on the track at all expense spared (although it would be nice). I'll leave that to the racers and the guys with the deep pockets. I think the A6 is probably the best tire, and God bless those that can afford to consistently replace them!

It do beleive the R6 is probably the better tire, but I specifically remembered the 710 lasting a LONG time. I remember being suprised how long it lasted and how well it kept its initial grip level vs. the R6. Which at $1400+ a pop, may take priority over a little performance.

Frank, what was the wear rate of the 710's you used vs the R6's? From an economical perspective, do you see getting more miles out of the 710 with camber being equal?

mountainbiker2

I've switched back and forth a few times. I can't tell you which is faster, but I can tell you when you're running Kumho's you only need -2.1 neg. camber. The Hoosiers will need -2.7 neg. camber. The back seems to be fine at -1.2 neg. camber for both. At this point, I'm running Hoosier's for low grip lots and Kumho's for high grip lots. I autocross mainly.

Steve

bowmanized

Hoosiers buddy. One of the best products we make as Americans.