Kumho "Tire Tips" says to overinflate for long trips & more...

Messages
3,833
Location
NEPA
"Extended driving, overinflate by 4psi" "Rotate every 5000, rotate when changing oil" (I rotate for seasons) "Tires should be rotated considering degree of overall damage" (I assume that means damaged tires in rear) ...discuss among yourselves.
 
Messages
2,724
Location
Herndon, Virginia
My new Hyundai came with the 722 stocker Kumho. Worst tire I ever had. Slippery when wet, easy to plane at moderate interstate speeds, and crummy wear rates. Further, when inflated to within 5 psi of maximum pressure (44 PSI), the Kumhos are so hard they beat the crullers out of the front suspension. In another 10K or so, they'll be all done, but I swear my instinct is to get em off NOW , junk them, and go back to the SP Dunlop Sport A2 Plus, merely the finest rain tire I've ever had on a car. I sincerely regret not demanding they be put on the new car when I traded my old car.. Over inflate THESE Kumho things? No thanks..
 
Messages
3,931
Location
Somewhere in the US
Too crazy: My book says that Hyundai's don't use any more than 30 psi, so you're over inflating by 9 psi, and that's what's likely beating the crullers and causing the wet traction problems. Drop the pressure to 33 psi and report back.
 
Messages
2,724
Location
Herndon, Virginia
Thanks, Caps! Yeah I did that, actually, 34 front, 32 rear. THAT is when the wear rate on the fronts went way up. They don't beat the suspension anymore, though. Doesn't change matters in the rain unfortunately. Problem is, even though these don't wear well, they seem to be a very hard compound, making them pretty slippery in rain. I realize Hyundai wasn't going to put a great tire on an AccentGT, but jeeez..
 

JHZR2

Staff member
Messages
45,974
Location
New Jersey
extended driving at high speeds and/or driving with a full load has been grounds to inflate tires above spec, per Mercedes-Benz, for years and years. I trust their engineers pretty well (they designed my 83 300D, which is one heck of a wonderful car!), so think theyre onto something. My saab takes 41 psi on the fronts, 38 on the rears, for normal driving. Perhaps that is why it gets such goo dmileage. Suprisingly, they dont seem worse for wear. toocrazy, I agree with you regarding comments on the sport A2 tires. Theyve done really wellfor me in snow too! I use them on the 94 integra, the 94 previa, the 83 MB, and likely will use them on the 91 BMW too. theyre a bit soft on the outer lugs (experienced higher wear out there on the MB and toyota, regardless of axle), but even if they swear a bit faster, their price makes up for it IMO. JMH
 
Messages
1,856
Location
PA
I overinflate by 2-4psi typically to get better wear unless in the snow on most all tires. Kumho probably states the overinflation spec because they tend to use very few plies and need the pressure to keep the tire together at speed [Smile] All in all kumho is the cooper tire of Korea, not bad, but not awesome - depends on the tire you get.
 
Messages
2,724
Location
Herndon, Virginia
Agreed, Dominic.. It isn't a GoodYear Regatta, but it's NOT a premium tire, and on a $10,400 AccentGT, I didn't expect prime donuts after all. On this car, the Kumho tires inflated to the max recommended 44psi is WAY harder than I'd ever run, gas mileage considerations be dammed. Every pothole, pebble, grain of sand, and rumble strip sets up a whack that travels through the entire vehicle. JH, the reason the A2 Plus's wear that way is a different compound and rib design on the outers, if memory serves. They're directional-centric, and must be installed on the correct sides of the car for the rib and compound design to be oriented properly. Rotation is front-back only, never a side to side flop. I've seen folks complain about this tire, and I've suspected they weren't installed to the proper orientation, but who needs THAT argument? [I dont know] Sport A2s don't run 60,000 miles, but the quiet and the feel and "stick" these tires have in wet conditions (equal to dry traction as tested by me on exit ramps and twisties) trumps the wear considerations for me, a driver that goes up and down the east coast at high speed from Boston to Tampa many times a year..
 
Messages
2,724
Location
Herndon, Virginia
well, that may apply to econo-boxes, but my gal's Infinity came shod with some S-Hot V-Rated Perellis that were $255 a tire to replace. Lots of the performance sedans are these days. She bought General Tires for $100.00 a tire, (ok, ok, *I* did, she was at work that day). Can't tell the difference, but then, she doesn't travel many racetracks or skid pads...
 
Messages
177
Location
Earth
quote:
Originally posted by toocrazy2yoo: ...They're directional-centric, and must be installed on the correct sides of the car for the rib and compound design to be oriented properly. Rotation is front-back only, never a side to side flop...
I'm sorry but your info is incorrect, the SP Sport A2 Plus is NOT a directional tire in any way, shape or form. It has to be installed with proper side out as marked on the side wall. But they CAN be cross rotated, to extend life and keep the noise under control, yet maintain the outside-orientation mentioned before. The company who makes it, doesn't put a rotation direction on the side wall for a good reason, and I tend to believe the source [Wink]
 
Messages
2,724
Location
Herndon, Virginia
If it suits you, flop em.. Dunlop's docs from the dealer demanded no cross-swapping. The website now claims non-directional asymetrical tread. They also have a center tread pattern that is NOT the same from "front" to "back". The sipes angle differently toward the center. When I get them back on this car, I'll follow that, all due respect.
 
Messages
6,089
Location
northern Alabama
Can you scan the documents that demand no cross-swapping? I just bought these tires a few months ago & nothing of the sort was conveyed from the mfg or installer. I believe I even emailed Dunlop asking if you can cross rotate & they said no problem. I'll see if I can find that email. Now, some folks don't like to cross rotate due to fears of tread separation. Is that the case here?
 

JHZR2

Staff member
Messages
45,974
Location
New Jersey
You are right, that the A2 needs to be oriented correctly, and needs to be kept on the correct dise of the car when rotating. I will say that I average 40-50k on my A2s bfre getting rid of them. At that point the outer lugs are worn down far enough to demand replacement not bald, flat, etc., just worn down enough with the rest of the tire). 40-50k isnt bad, but considering that other tires, like toyo A05 tires last us in excess of 80k, its just less than that. Still the A2 is one heck of a great tire for the $$ JMH
 
Messages
2,724
Location
Herndon, Virginia
Ben, I had those tires on my 92 Elantra, the maintenance docs and pamphlets I got with them went with the car when I traded it. But the dealer and the docs were quite specific back then, but meanwhile, either recently, or through contradiction back then even, the Dunlop website advertises them as non-directional, or whatever. Meaning, swap sides if you like, I guess. But I definately read it on the pamphlets they gave me, and was advised by the dealer to observe the no-flop rule. MEANWHILE, the sipes are arranged in a certain direction, and would be reversed if the tires were moved to the other side of the car. Would this set up problems? Who knows? I'm certainly not going to argue one way or the other, but on these little roller skates I drive, the wear issues aren't side-to-side, but rather front to back, so *I* would flop em front-back, back-front. I wouldn't lose sleep over it, BenJamm. It would make little difference in wear (assuming you don't have pulling issues) to not flop sides. The critical thing IS to rotate them off the fronts, however, they wear a LOT faster on the front, obviously. JHZ, I coulda cried when I thought about it later, I barely had 10K on mine when I traded that car, and the little nibs were still on the treads, they were wearing so purely. I should have made it a condition of the purchase to have them installed on the new car. The MPT24 Interstate battery, too.. Ack!!! They auction their trades in Mexico, I understand.
 

Auto-Union

Thread starter
Messages
3,833
Location
NEPA
I must have purchased two dozen A2s. Nearly the best in snow, very quiet. I consider it a touchstone to compare others to. Now, I usually put them on other peoples cars and try new tires out on mine. Mom has them as well as MiL. I never had a complaint. A few years ago, one "reportedly" blew out on my wife's Quantum Syncro. The car was totaled, that cooled me off of Dunlop, but went back after considering how well they worked. Also, I have never heard a complaint about Kumho ASX, this coming from some real car guys whom I trust.
 
Messages
40,629
Location
Great Lakes
quote:
Originally posted by toocrazy2yoo: I realize Hyundai wasn't going to put a great tire on an AccentGT, but jeeez..
OEM tires on new cars are always a cr/\p shoot, regardless of car. Car manufacturers have their deals with tire manufacturers, and they'll use the cheapest tire they can get that meets some basic specs that they set forth.
 
Messages
40,629
Location
Great Lakes
quote:
Originally posted by Auto-Union: I must have purchased two dozen A2s. Nearly the best in snow, very quiet. I consider it a touchstone to compare others to.
Any first hand experience with Nokian WR? I was curious how the A2 compares to the WR. From all I've read and heard, the WR should be better, mainly during winter, alas it's more expensive.
 
Messages
1,856
Location
PA
Bottgers I beg to differ. My Avon m550's run 3-ply poly sidewalls and 7-ply tread. Look at a michelin, single ply sidewalls, 2-3 ply tread. Then look at any Kumho... Big difference in construction durability if you hit the tire hard.
 
Top