Greater wear on rear tires?

[NMBurb02]

I rotated the tires on the Burb for the first time (7,500 miles) about a month and a half ago and when doing a once over on them the week before last I noticed that the front tires had slightly less tread than the rears. When I bought the vehicle, the PO had recently put on two new tires and the other two were in dire need of replacement. I am not positive on how long the new tires were on there before my purchase but believe them to be a few weeks max with little driving. Not wanting two sets of tires with different handling and wear characteristics or tread wear warranties (locking me into a loop of purchasing two tires at a time), the two new tires I purchased were the same brand, model, and size (1" taller than OE) of the two newer tires, making all four Falken Ziex S/TZ04. I bought the tires at DT and their policy is to put new tires on the rear so the tires that are now on the front and have about 1/32-2/32" less tread (even wear on all four tires) are theoretically the two newer tires that spent all but the last two weeks on the rear.

If it matters, I ran the tires at about 40-44 psi (OE is 35, max pressure on the tires is 44); the normal load is one or two adults in the front, an infant and her car seat in the middle seat, two small children and their car seats in the back seat, and a stroller in the back, resulting in a fairly light back end; driving is probably 70/30 to 60/40 highway/city; the driving style is mostly tame with no burnouts, no sliding around corners, and only one 5 mile offroad trip; and a front end alignment was done shortly after buying the two newest tires.

Is there something that could explain greater wear on the rear tires or is it more likely that DT put the new tires on the front, seeing as the tires being replaced were up front and the rears were still pretty new?

 

[eljefino]

Look for date codes to solve a couple of your mysteries, and buy a tread depth gauge-- they're only about $2!

I tend to believe you got two new in the front in purported violation of their own policy.

Also don't take tire tread readings from the tire store as gospel; they could be guesstimates.

 

[Ken2]

Don't assume that the rear axle is in alignment. It can be misaligned due to a manufacturing error, manufacturing tolerance, or crash damage. Get a 4-wheel thrust alignment that checks the alignment of the rear and if OK aligns the front to match the direction of thrust of the rear. If the rear is way out it can be fixed.

 

[NMBurb02]

Originally Posted By: eljefino
Look for date codes to solve a couple of your mysteries, and buy a tread depth gauge-- they're only about $2!

I tend to believe you got two new in the front in purported violation of their own policy.

Also don't take tire tread readings from the tire store as gospel; they could be guesstimates.

I had thought about checking date codes but the wife is out with the kids right now. Also, the dates of install are so close that it wouldn't surprise me if the newest installed tires were manufactured before the older ones.

I have meant to get a tread depth gauge but always forget to grab one when at the auto parts store. Also, I wasn't measuring the whole tread with my depth difference estimate. These tires have higher wear bars to allow for easier assessment of uneven tread wear and those are what I was looking at. Also, it was my estimate, not a tire shop's, as I did the rotation. My local DT shop does accurate tread measurements as they check the depth with a gauge before even writing up the service order. I plan on taking the tires in to be rebalanced very soon as one wheel does not have a weight on it and I doubt the tire and wheel are completely balanced without one.

 

[NMBurb02]

Originally Posted By: Ken2
Don't assume that the rear axle is in alignment. It can be misaligned due to a manufacturing error, manufacturing tolerance, or crash damage. Get a 4-wheel thrust alignment that checks the alignment of the rear and if OK aligns the front to match the direction of thrust of the rear. If the rear is way out it can be fixed.

I had thought about that, but would the wear on the rear tires be uniform if the rear alignment was off?

 

[Kuato]

There are too many vehicle owners that never rotate their tires. PO probably let the fronts wear until they were unsafe, then had new tires put on the rear.

I'd count your new tires as the first rotation for this set, run it 5k then rotate again aiming for 10k rotations after that if wear allows.

 

[fdcg27]

The answer is obvious.
Your wife burns the tires at every opportunity when you're not looking.
She secretly yearns for an old school Road Runner with a 440 six pack.

 

[NMBurb02]

Originally Posted By: fdcg27
The answer is obvious.
Your wife burns the tires at every opportunity when you're not looking.
She secretly yearns for an old school Road Runner with a 440 six pack.

Wouldn't surprise me! The GP has an average mpg readout and I will drive the car for 250+ miles and get 19.5-21.0 mpg in that time and when it comes back after she puts 50 miles on it from what should be mostly consistent highway driving, it's down to 18.0 or lower...without having reset the readout!

And she did give in rather quickly when I proposed adding a cat back exhaust, headers, intake tube, and tune to the Burb. It was something along the lines of, "Just get whatever you want."

 

[Kuato]

Originally Posted By: fdcg27
The answer is obvious.
Your wife burns the tires at every opportunity when you're not looking.
She secretly yearns for an old school Road Runner with a 440 six pack.

 

[CapriRacer]

A couple of thoughts:

Drive tires tend to wear in the center, steer tires tend to wear in the shoulders.

On a RWD vehicle like a Suburban, the wear rates are about the same front to rear, but in different places across the face of the tread. In order to get the maximum life out of a set of tire, they need to be rotated.

 

[jdawg89]

Originally Posted By: Kuato
There are too many vehicle owners that never rotate their tires. PO probably let the fronts wear until they were unsafe, then had new tires put on the rear.

I'd count your new tires as the first rotation for this set, run it 5k then rotate again aiming for 10k rotations after that if wear allows.
I'll admit I'm very guilty of this...never rotate...and the fronts on the truck are bald and the belts are broken so it goes "thud thud thud" down the road....

 

[Cup of Joe]

This seems to be normal on some trucks. I have found this to be the case on my Ranger. I've owned it since new and using my tread depth gauge I have measured increased wear on the rear tires across the entire surface of the tire compared to the front tires. I have over 55k miles on this set of tires to this point, I compare the wear on the fronts to the wear on the rears and base my decission to rotate off of that.