Contour Enthusiasts Group Archives Forums Modifications Wheels & Tires Kumho MX review

Had these installed Friday and have run about 100 miles on them, time for an initial review.

Cost: In 205/55R16, they cost $88/each + shipping from Tire Rack ($33 for all 4) plus mount/balance/state fees of about $80.

Looks: OK, not spectacular, but I don't really care.

Ride: Creamy. No significant change from the 15" snows I just took off. I was very surprized by this aspect. No impact harshness or noise over expansion joints.

Noise: Well, they're a bit loud, but I don't care. That's the price to be paid for a max performance tire, just crank up the stereo a bit. Much louder than the Kumho 711 Supras they replaced. I bet they get a lot louder as they wear too. Concrete makes them sing.

Grip: Seems to be verrrry grippy, even at their full 10/32 tread and with just enough miles on them to get the mold release compound worn off. I'll know more when I go ripping around the ring road at the local mall and run around on the back roads here as soon as it warms up out of the 30s again. Much, much better grip than the Kumho 711 Supras though.

Overall I'm very happy with them. I'll post again once I get some miles and real work on them.

Scott

Well, I'm sure SandyEggo really sucks for driving too Warm year-round, lots of nice "scenery", etc. I could have moved anywhere and I moved from Buffalo to Rochester. And I fricking hate snow. I must be a masochist.

Scott

I just threw on a set of used 205/55R16 MXs. After some F1-style tire warming swerving (not on the road, of course) to get the skin off and warm them up, I had a pretty good romp.

Straight line: either smoke or wheelhop. Harder to launch than the Fuzions, but I think they have a little more grip. I was at 35 psi, so they might hook better at lower pressures.

Braking: With ABS they felt good, and the compound/carcass liked crappy pavement about as well as the smooth stuff. Without ABS threshold braking at low speeds was a chore. Again, they fall of quickly at the limit and keeping it on the edge is tricky. Not R-comp tricky, but tough for a street tire. I'll see how this changes as they get re-broken in.

Trasitions: The big sidewalls are sort of mushy. The Fuzions had a soft sidewall for a sporty tire, and I was hoping for something more Azenis-like here, but I didn't get it. They're not rolling over at 35 psi like the Fuzions, but they are still softer than my springs. But, it's a fairly linear feel, and I think it'll be fun and forgiving.

Steady-state cornering: loads of grip. These tires are tenacious. Not worlds away from the Fuzions, even after they were heat-cycled and worn into oblivion, but the butt-dyno says they're better. They have a very smooth (but short) transition into sliding. The tall sidewalls let me run huge slip angles and change the attidude of the car without getting loose, though. They do not squeal on dry pavement, they just let go and leave thick dark black marks: very much like an r-comp. These will be tougher to drive than the Fuzions, which had a very forgiving "double-hump" slip-angle vs. coeffeicient of friction curve. But, the tall sidewalls will make it happen slower. I could not induce excessive oversteer on a ~30 mph skidpad, even with the inside rear lifting. I think that this means they like camber. The fronts really felt over-cooked. I'll try again with the race setup of ~3* camber up front and see if the rear will get loose. At higher speeds (~50-60mph) it got wiggly when lifting at the limit, but nothing dramatic. Again, camber should improve rotation.

Real-life stuff: These are DD tires. They are very loud. They hum, and they get louder as they get warmer and grippier. They tramline a bit, but I think they are better than the Fuzions. I have yet to try them in the wet. Ride: well, they're a lot stiffer than my 14" winter tires. But they're still much softer than my springs, so it's tough to tell what they'd be like on a softer car. Ride quality is always crap in my car, even on pillow-soft tires.

In about a month I should be able to try them on the course, and we'll see how that goes.

Are you speaking of Fuzion ZR1's? I have been using these tires for the last year and a half, and I have noticed nothing close to a "soft sidewall".

The Fuzion ZRi has a soft sidewall for a high-performance tire. They roll over very easily. I had to run 50 psi during autocrosses to keep them off the sidewall.

I guess since I don't auto-x, I haven't noticed. Although I do drive pretty aggressively some times. I can't imagine running 50 psi. Isn't the max 44?

Drive some Falken Azenis 215s (the old ones) sometime. Everything seems soft after them. But even for street driving, there was a ton of slop in the Fuzions. Most sporty tires like the BFG KDW2 and KD, Yoko AVS ES100, etc. have stiffer sidewalls than the Fuzion ZRi. Of course, they're fine (and you might not even notice) if you don't have stiff springs, but they were noticeably squishy on my car.