Here's a little article about the Kumho Ecsta 711 tires that I run on the 1990 BMW e30 325i. One wet night, I was getting on to the expressway on ramp, and I was getting on it - 2nd gear, 50 mph, about to go into 3rd, and up ahead just out of the reach of my headlights, I see an armadillo crossing into the street. I saw it, and had plenty of time to stop, so I got on the brakes as hard as I could to try to lock up the brakes and make the Kumho's stop spinning - and it didn't happen - I was pretty hard on the brakes, and I felt the gripping force from the tires as I came to a hard stop about...
20-25 feet from the armadillo (which are blind) and let it cross the street. I knew that these tires were great, but never knew how much they could handle. I used to run the Falken (crap) 245/45/16 tires on my car, with the Racing Dynamics RGP road wheels, which were very bad tires. They wore on the inside very fast and uneven on the fronts, and had horrible wet traction. I got the Kumho's from my friend Luis on the new wheels that I have - and they were slightly worn, but still had tread in the fronts, and the backs were ok, still are today - Since December of 2004, I've had the tires on the car, and countless miles have been put on them. I have the Lemforder offset rubber control arm bushings in the front, so the camber is sitting negative right now, which will make the car ride on the inside and center of the tire (with the e30 M3 springs installed) so now they are showing signs of wear.
Recently, I had to get new tires on the 2001 Corvette - they come from the factory with the Goodyear Eagle F1 EMT (runflat) tires. The ride quality in these tires was pretty harsh over bumps, but excellent in the rain (very excellent) even with the low tread depth. I went shopping around for new tires for the vette, and these EMT's run $302.00 for the front and $392.00 for the rear, each tire. I did some looking around on the internet mainly on the corvette forums for suggestions on changing from the EMT's to a standard tire. A lot of people found that changing from the EMT's was a big bonus - as far as ride quality, and cornering. Paul, who owns 2 C5's, a 1999 and a 2000 (recently sold the 1999 for $22,500) said that when it came time for him to sell the car, he went out an spent $1,300 for brand new Goodyear Eagle F1 EMT's to keep the resale value of the car as high as possible, because as it stands, the car is 100% stock and original.
Paul recommended to me that if I plan to sell the vette, to install the original Goodyear tires on the car, to keep the resale high, and originality of the vehicle, and, if I plan to keep the car (which I did), go with another make of a tire.
I shopped around for the best price on tires, and went to Sears because they had the best deal on these tires. They are the Kumho Ecsta ASX All Season Radials, Front: 245/45/17 - $134.98 each ($269.96), Back: 275/40/18 - $174.79 each ($349.58). Grand total, including tire disposal, valve stems, road hazard, taxes and balancing came to $812.88, compared to the Goodyears at $1,388.00, just for the tires alone)
Treadwear: 420 Traction: AA Temperature: A
What these mean, and are very important and almost ALWAYS overlooked by the general consumer, are as follows.
The treadwear grade is a comparative rating based on the wear rate of the tire when tested under controlled conditions on a specified government test course to 6,000 miles(9600Km). For example, a tire graded 150 would wear one and a half (1 1/2) times as well on the government course as a tire graded 100. The relative performance of tires depends upon the actual conditions of their use, however, and may depart significantly from the norm due to variations in driving habits, service practices and differences in road characteristics.
TRACTION AA, A, B, C
The traction grades from highest to lowest, are AA (the highest) A, B, and C and they represent the tire's ability to stop on wet pavement as measured under controlled conditions on specified government test surfaces of asphalt and concrete. A tire marked C will have the lowest traction performance.
(note: THE TRACTION GRADE ASSIGNED IS BASED ON A WET BRAKING (STRAIGHT AHEAD) TRACTION TEST AND DOES NOT INCLUDE CORNERING (TURNING) TRACTION.)
TEMPERATURE A, B, C
The temperature grades are A, B, and C, representing the tire's resistance to the generation of heat and its ability to dissipate heat when tested under controlled conditions on a specified indoor laboratory test wheel. Sustained high temperature can cause the material of the tire to degenerate and reduce tire life, and excessive temperature can lead to sudden tire failure. The grade C corresponds to a level of performance which all passenger car tires must meet under the Federal Motor Vehicle Safety Standard No. 109. Grades A and B represent higher levels of performance on the laboratory test wheel than the minimum required by law.
Take this information into account when purchasing tires.
I really like these new tires - they have an excellent smooth, quiet ride, and handle bumps and dry pavement very well - and just so that I could really tell you how I feel about them, I took the vette up to 140 MPH (do I need to tell you not to do this on public roads?...) to see if these tires were all show and no go, or really held up to the name - and yes - they deserve the Kumho name on them, and my approval. One thing you might take into serious consideration, is that the money you save from buying EMT's, go out and get yourself a portable air pump, which plugs into your cigarette lighter, and tire patches - in case you need them...it's a great investment, and since the C5 doesn't have a spare tire, you really should consider this.
Jeff Seabrook has been with us since Sunday, February 15, 2004.