Just had my Elantra in for her 30K ATF flush. I’d been running her tires at 44 PSI for probably the last 10K for fuel economy reasons. The tires says 44 PSI on the sidewall, while the sticker on the car says 34 PSI.
The dealer noted that my tires are cupping and suggested an alignment, which I declined; I can get the alignment done cheaper elsewhere by perfectly competent shops.
Previously, I noted a slight shimmy above 65, and took her in for an alignment.
When I picked her up, I was told that it aligned nicely, except for one of the measurements*, where it could not be brought within tolerance; the car was 0.2 degrees out of spec on that measurement.
I drove off, and the high-speed shimmy was no longer there, but showed back up in about 3 days.
I’ve seen some posts on various boards wherein folks complained that their Elantra had sustained permanent failure due to overloading.
Anyone have any guesses or observations as to what’s going on here?
Could it be the inflation levels?
Is it likely it’s the suspension wearing out?
I can’t remember which one didn’t adjust properly, but I believe it was the most obscure of the alignment variables.
Just out of curiosity, what year is your Elantra? I have an '08 with 20,000 miles on it that’s had alignment problems and uneven tire wear. I haven’t overinflated the tires, though.
Old tires
Some will jump on you for over-inflation of the tires, but this is not the cause. Car Talk has admitted, begrudgingly, that this is actually safe and effective.
Under-inflation is the big no-no.
Once your tires are screwed up, alignment and balancing won’t help shakes and shimmies.
The 44 psi on the sidewall is a maximum safety limit. It is NOT a recommended pressure. The official recommended pressure for use on a given vehicle (in this case, 34 psi) is determined by the vehicle manufacturer, not the tire manufacturer.
Overinflation can cause premature wear on the center portion of the tread, and sometimes less traction on soft surfaces. Underflation can cause premature wear on the outsides of the tread, excessive heat buildup in the tire, and excessive flexing which can shorten tire life.
Cupping is caused by suspension or wheel balance issues (a laPhilster’s list), not by over- or underinflation or misalignment. Feathered wear, which resembles cupping in one aspect, is caused by misalignment. The dealer’s recommendation of an alignment because of cupping raises the question of whether the dealer doesn’t know what causes cupping, or doesn’t know the difference between cupping and feathering.
Shimmy is almost always caused by wheel balance, steering linkage play, or a faulty tire, not misalignment.
It’s unlikely that the .2 degree misalignment is significant.
What to do:
~Find out if the abnormal wear is indeed cupping, or is feathering.
~If it’s cupping, find and fix the cause (in the absence of an obvious detectable cause, it’s almost always weak shocks).
~Be aware that the abnormally worn tire(s) may never recover. Replacement may be necessary if wear-related symptoms become bothersome.
Site that helps explain some of what’s being discussed, with illustrations.
I was curious as to which Elantras have alignment issues.
When I took it in for the 15,000 mile service, the dealer found that it was out of alignment, though they didn’t give me the specific measurements. I’d noticed a shimmy that went away briefly after the alignment was done, but it returned as well. When I brought it in for the 20,000 mile service and asked them to balance the tires, they told me that the vibration was due to uneven wear (which they showed me; the insides of the rear tires were far more worn than the outside) and told me to plan on new tires within the next few months and not to bother with balancing.
I’d heard bad things about the Kumho tires it comes with; a friend told me he’d had to replace them on his Mazda within 20,000 miles. I don’t know if they have a bad reputation elsewhere or if his problem was a fluke.
44 PSI on the sidewall is the maximum tire rating. Putting that much pressure in those tires on that care will certainly affect the handling and braking, probably making the car less safe. For example your stopping distances are probably greater.
It should be noted that driving on cupped tires can lead to your next set being cupped, because you are beating the frigging daylights out of your suspension, and the shocks/struts/springs (even the bushings and some bearings) are gonna be less resilient, and then your next set of tires will gradually cup (because I doubt you are gonna rebuild the entire suspension).
I’ve seen uneven tire wear from gross over-inflation that feels like cupping/feathering. It may be that the over-inflation exacerbates another problem. Replacing the tire and running normal pressure did not produce the same results.
Mileage is a hair under 30K.
I haven’t changed the tires since yesterday, so presumably at least one of them is cupped as the dealer notified me of yesterday.
At that mileage, I’d want to know my wheels were in good shape, and that they are properly balanced. I’d back off the tire’s max tire pressure and run the door placard’s max pressure.
Suspension wear is not an issue, but damage would be an potential problem. But it wouldn’t be worn shocks/struts/springs/bushings – not at that mileage.
I have Hankooks (Ventus V12 Evos) on my G35 Coupe. They are Z-rated, ultra-high performance tires. They are pretty good, but you have to wonder about all the reasons they are half the price of more world-renowned tires.
I am not familiar with cupping being a problem with certain tires. It could be the tire, but you gotta chase the most likely things, not the least likely things.
Suggestions towards causes were already made, and when you’ve exhausted the list, then you can focus on the tires as the cause, but you should be seeing them as the victim of another problem, which they likely are.
Reading this carefully, I’ll be taking her into a good tire shop and getting it looked at.
The combo of high-speed shimmy plus cupping leads me to believe that I’m looking at wheel balance issues… and damn, I was leaving on vacation tomorrow morning.
Funny thing… in looking up info on my G35 tires, I found specific reference from Hankook that notes they are designed with a very specific outter-tread design to prevent feathering and cupping issues that are common complaints from G35/350-Z owners.
I am not shocked, because some suspensions are going to be tougher on tires. I would not expect a generic suspension in a Hyundai Elantra to push the tires anywhere near as much as a multi-link, high-end suspension that rides very harsh and pushes the tires.
Well, to close out this story, I had one tire shop, one retired mechanic and a mechanical engineer check this car’s tires for cupping.
Not a single one of them could find any hint of that condition.
There’s a certain Hyundai dealer near Green, Ohio, that I’m not using again for service unless it’s to do a warranty invoke.