[rrsteer]

I am facing a strange problem with my Kia Carnival. Its rear tyres are wearing off prematurely. At the same time, the front tyres (which one expects to wear off sooner in a heavy front wheel drive car) are not only holding well, but comparatively show no sign of wear.

Let me share a chronological account, which will make it easier to understand the issue faced and solutions applied so far.

Aug '21 - New car purchased.

Sep '21 - First time noticed a missing tread line in both the rear tyres and reported it to Kia dealership.

Nov '21 - 5k inspection. Issue reported again and as a solution wheel alignment was done. Note: Carnival has a rear independent suspension, thus rear wheels need alignment too.

Mar '22 - 10K Service. At this point I had stopped monitoring the tyres thinking the issue to have been solved. But as part of service all four tyres were aligned, balanced and rotated.

Aug '22 - 20k Service. Again all four tyres aligned, balanced and rotated at the dealership as part of the service.

Oct '22 – The car would have done about 24k kms. I was on the highway driving back home from Delhi, when something felt amiss -like the one of the tyres has suffered a puncture. Stopped to check, and found one of the rear tyres to have completely worn off. Note this was at the fag end of the journey and I had already driven the car for about 600 kms that day. Reported the incident to the Kia dealership and on their advice got fresh new tyres at the front and the existing front tyres were put on the rear. Thereafter the tyres were aligned and balanced at the dealership.

The completely worn tyre:


Dec '22 - 30k service. The rear tyres looked to be in not so good shape and on the advice of the dealer just a day before the 30k service appointment got two new tyres. This time the new tyres were put on the rear. Also, as part of the service all four tyres were aligned and balanced. The dealer also checked the rear suspension and ruled out any issue with the suspension. The car's odo reading was about 29.5 k kms.

After the 30k service, I kept a keen eye on the tyres. My gauge was any deformation in the tread design and found none - though I had a suspicion that one of the tread design lines was fading in the rear tyres.

Mar '23 – The car would have completed about 33k kms. I noticed one of the lines (on the outside) of the tread design missing from both the rear tyres after I returned from a outstation trip. Reported to the dealer and contacted Kia directly for the first time. Dealer again checked the alignment and updated it based on some new parameters. I was told their was close communication between the dealer staff and Kia engineers. They asked me to drive another 1k - 2k kms and bring the car back for another evaluation.

The condition of the rear left tyre @33k kms.(Note the missing outer tread line; the inner tread line is visible)



And the right rear @33k. Similar to the left tyre - the outer tread line is gone but the inner one is still visible.



April '23 – On the Thursday of the last week of April, I dropped the care for inspection. According to the GM service at the dealership, the issue was probably solved, and the alignment parameters were also all good. But I was still advised to bring the car back for re-evaluation after driving another 1-2k kms. After getting the car back, I could myself inspect the tyres only a day later (meanwhile the car wasn’t driven). Lo and behold, I found another tread line missing (this time the one on the inside) from both the rear tyres. Please check the pictures below:

The current state of rear left tyre @35.5k kms. Now the inner tread line has worn off too.



Similar to the left rear, the right rear tyre too has lost its inner tread line.



Also please note and as mentioned earlier, the front tyres are spared while the car goes about chewing the rear ones. Please see below the picture of the current state of front tyre. Do note that while the front tyres have done ~11.5 k kms, the rear ones have done just 6k kms.

Current state of 11.5k driven front tyres.



My intention is not to criticize Kia or the dealership in this thread. (I am open to creating another thread for that topic ) What I am really seeking is advise from the learned members of this forum to help understand/diagnose the root cause of the problem.
The dealership has ruled out any fault in the rear suspension. The rear alignment is also ok – the parameters are all under the range provided by Kia. Typically, the dealership shares a printout of the before and after alignment parameters and I haven't really ever noticed the parameters to be that off of the desired range. So, if the suspension is ok and the alignment too is correct, then what else can or should be checked?

[Shreyans_Jain]

You had raised this on the Kia Carnival main review thread as well. Has the alignment been checked only at the dealer’s or have you shown it to your reputed neighbourhood tire shop as well? It is possible that the dealer’s alignment rig has its calibration out. For what it’s worth, I’ve never had a service centre get the alignment right on any of my cars ever, across brands. Have always relied on tire shops for this.

Sometimes, it takes a good old fashioned manual alignment with a thread, weights and skilled hands to get things right.

[SumitB]

Posting here after a long time. Thanks to Sheel for the encouragement to participate.

I took delivery of the Carnival on the 22nd of January, 2023. Am currently on 55xx odd kms. It is raining in Noida today so I cannot post a video but I will post one tomorrow and verify if there is any such issue on my vehicle. The unit I have was manufactured in January 2023.

[TorqMaster]

Thank you rrsteer.

Can you post the tire size and brand which you have? Since its a heavy car, possibly the tires are eaten fast?
I drove an equally heavy van but in the US where the road conditions were much much nicer so hence cannot comment as a comparison. But i never had to change tires due to this issue.
Maybe a thicker sidewall and harder compound tire might live longer with compromises on road noise.

[Shreyans_Jain]

Originally Posted by TorqMaster

Thank you rrsteer.

Can you post the tire size and brand which you have? Since its a heavy car, possibly the tires are eaten fast?

Carnival comes standard with 235/60R18 size tires, MRF Wanderers. The size is adequate for the application and sidewall height is also good. Tires are fine. This is a global product in a fairly workhorse kind of category (minivan), and this same size is there in western markets as well. Had the size been an issue, this problem would occur on all Carnivals.

[rrsteer]

Originally Posted by Shreyans_Jain

Has the alignment been checked only at the dealer’s or have you shown it to your reputed neighbourhood tire shop as well?
Sometimes, it takes a good old fashioned manual alignment with a thread, weights and skilled hands to get things right.

I am not getting the alignment checked from another tyre shop due to 1) fear of loosing the warranty 2) I have not found a tyre shop in my city whom I can trust. I have visited the largest and the most popular one - you can buy any tyre from them, but the way they do the alignment doesn't inspire confidence. Most are not even aware the Carnival needs a rear alignment too. 3) All Kia dealers being relatively new have very good equipment. The alignment machine that I see at the dealership 'looks' much superior to any other machine I have seen. But yes, I can try taking it to another Kia dealership. Had actually thought about doing it.

But, I also think mine may not be an isolated case.

Originally Posted by SumitB

Posting here after a long time. Thanks to Sheel for the encouragement to participate.

I took delivery of the Carnival on the 22nd of January, 2023. Am currently on 55xx odd kms.

Thanks Sumit, will look forward to your post. And, thanks @Sheel!

Originally Posted by TorqMaster

I drove an equally heavy van but in the US where the road conditions were much much nicer so hence cannot comment as a comparison. But i never had to change tires due to this issue.
Maybe a thicker sidewall and harder compound tire might live longer with compromises on road noise.

Actually in US the Carnival or the Sedona was also sold with 17 inch wheels. Once the car is out of warranty I'd definitely want to try that size. But that can happen only after 2026!

Originally Posted by Shreyans_Jain

Tires are fine. This is a global product in a fairly workhorse kind of category (minivan), and this same size is there in western markets as well. Had the size been an issue, this problem would occur on all Carnivals.

As I mentioned above, I think mine may not be an isolated case. Please look at the pictures of two different Carnivals. I believe both were manufactured after Aug'21 - as they had new Kia logo. Took these pics this weekend. Specifically went around the city hunting for other Carnivals - found just two and both had worn rear tyres.

First Carnival

The rear tyre - outer tread line missing


The front tyre - looks fine



Second Carnival

The rear tyre - outer tread line missing


The front tyre - again looks fine


Sorry if the pics aren't very clear. I was feeling v strange clicking pics of others cars.

[chinkara]

Any fouling with mudflaps?
Else, check alignment, as others have suggested.

[bravo6]

What tyre pressure are you running vs recommended? And what's the typical car load during daily usage?

Always ensure you set the recommended pressure when tyres are COLD, and check it the morning before you go for alignment.

My rear tyres are adjustable too, and I see this happen if I wait too long between alignments. I typically drive very slowly on bad roads, so the front doesn't go out of whack for quite a while.

Another thing to check is if there is an updated set of alignment values for your particular model year.

[SumitB]

ODO Reading: 5765
Tyre Pressure (Cold): Nitrogen 35PSI on all 4

I am sorry, I am not sure what I need to look out for here but it may serve as a benchmark for me to refer to in future and keep a watch.





















This video will probably give a better idea of the condition of the tyres currently:

https://youtube.com/watch?v=RLqro-0SqJg?feature=share

[mayankk]

Have you had the camber adjusted as well?
My Tucson has this issue of outsides getting worn, all four tyres, and was traced to camber.

[rrsteer]

Originally Posted by SumitB

ODO Reading: 5765
Tyre Pressure (Cold): Nitrogen 35PSI on all 4

Thanks for the pics and video, yours looks all fine. But I will suggest keep an eye on the tyre wear.

Originally Posted by bravo6

What tyre pressure are you running vs recommended? And what's the typical car load during daily usage?

My cars are as well kept and driven as any on this forum. Tyre pressure is checked regularly, and only when cold set at the value provided by the manufacturer -which is 35 psi. Also this car is not daily used, probably once a week or fortnightly, never heavily loaded and driven mostly on highways. As you would have read below alignment is done frequently and the one done @33k kms was with inputs from Kia engineers.

Originally Posted by mayankk

Have you had the camber adjusted as well?
My Tucson has this issue of outsides getting worn, all four tyres, and was traced to camber.

Yes the camber angle too is monitored.

[chinkara]

Originally Posted by rrsteer

The completely worn tyre:
Attachment 2445906

To me this looks like some scraping / fouling with the naked eye.

Originally Posted by SumitB

Attachment 2446022

Here again the well looks too close. In my Wagon R, I had some rear suspension issue for a bit which was causing tyre wear. Is it the case that the rear tyres are scraping the well / arch / flaps on bumps etc.? Do you hear any sound if you drive without AC and windows open?

Originally Posted by mayankk

Have you had the camber adjusted as well?
My Tucson has this issue of outsides getting worn, all four tyres, and was traced to camber.

Apart from Camber, check the fouling on bumps, sudden braking etc.

Getting another thought. As your treads are missing one by one, is there an issue with the roundness of the tyre? And also the flatness of the surface? i.e. is the load of the axle coming on one section as opposed to the whole tyre surface? And as that gets worn, to a different section?

[vsrikkanth]

My Carnival is 56000 kms old. It's true that rear tires wear out faster than the front and tire shops don't have a clue about it. I don't think the concept of front being heavier in a typical monocoque applies to Carnival. For some reason, I feel the rear of Carnival is also equally heavier if not more heavier than the front.

But I have not seen uneven wearing. I have also not done alignment @ dealerships simply because I don't trust them. Also in the 56k, more than 75% has been on highways and almost all of them had heavy cargo in place if not 7 people. I recently shifted my entire house on Carnival, except ones that won't fit - such as King size mattress.. So I may not be the right Candidate to talk about tire wear out. Note that I have so far replaced 3 pairs, always putting the new ones in front. But I have always had this debate @ tire shops if the new ones should go to the rear but haven't had the guts to go against professional advice.

Also to be noted, the same tire size is used in XUV 700, TUCSON and XUV 500 if am not wrong. Those are considerably lighter vehicles than Carnival so I believe the elephant takes it's toll on tires.. I maintain 38 PSI cold tire pressure - 3 psi buffer due to my laziness and have an external TPMS given that the spare tire is near useless..I use TUSA tire inflator to not depend on fuel stations for topping up and to avoid rare/slow leak of pressure from the mouth leading to sidewall tear on highway speeds...

[SNA411]

Are you the only driver of the car, or do you have kids in 18-25 year age group driving this car?

Reason being, just today I saw a kid; about 20-ish year old, launch an innova like it was a dodge hellcat.

[DRIV3R]

Originally Posted by SNA411

Are you the only driver of the car, or do you have kids in 18-25 year age group driving this car?

Reason being, just today I saw a kid; about 20-ish year old, launch an innova like it was a dodge hellcat.

Doesn't matter anyway as the Carnival is a FWD.