Why do our tires keep shredding?!

Short story: 3 tires, 3 brands, 2 cars, 2 drivers, 2 different routes to work. My girlfriend and I have both blown a combined 3 tires in the last 6 months. All had the wear on the inside edge.

Long story: I drive a 91 Miata. I had stock wheels, Cooper Fuzion crappy all seasons, no idea on alignment. Tires were around 15,000 miles or less and less than 2 years old. Tire blew on the return trip of a 400 mile road trip. At first it bubbled and made everything wobbly but I couldn't diagnose it. After 100 more miles (I know, I know that was dumb) it finally went bad enough for me to pull over and see the shredded tire. The rubber was falling off, the metal mesh underneath had frayed and poked through the rubber of the tire. A couple other spots had gouges of rubber missing. Inside edge of the tire. Fast forward 2 months and the same happens to my girlfriend in her 2008 Saturn Vue but one of her front tires. We replaced both fronts. Decent amount of tread left, no known age on the tire. No alignment in the last 3 years. Same description as before minus the chunks of gouged out tire missing. Last week the same happens to her right rear. It's a different brand/model of tire. Same description of rubber coming off, metal exposing through, inside edge.

What gives?

Are you running them too low on pressure? Have you been slamming them into huge potholes?

Seems to me you already answered it. Cheapish tires with unknown alignment. Maybe throw in a bit of weird heat cycling over the winter and you got the culprit.

alignment is the culprit. Just because the car goes down the road straight without any sort of pull does not mean that the alignment is spot on.

You might also want to look at your bushings and if you stand back from the car and look at how the tyres are sitting. I am willing to bet they are slightly leaning inwards

Toe issue is your problem for both most likely. I just had the same issue with my Abarth chewing it's pzero's up at 13k miles, but these cars run a very aggressive alignment spec.

Whoever is doing your alignments needs their rack recalibrated.

Knurled wrote: Whoever is doing your alignments needs their rack recalibrated.

or you need to start having alignments actually, you know, done.

In reply to ultraclyde:

What he said^

Wait, I'm sorry, I'm confused. You say you have no clue about alignment on your car but then ask why you're shredding tires?

Ya know, I was kinda wondering why my car stopped going when it ran out of gas...

mad_machine wrote: alignment is the culprit. Just because the car goes down the road straight without any sort of pull does not mean that the alignment is spot on. You might also want to look at your bushings and if you stand back from the car and look at how the tyres are sitting. I am willing to bet they are slightly leaning inwards

This. Not to mention, toe doe not have to be off much for them to rip tires apart in a hurry. Drove a car with -3.5 degrees of camber for a 15000 miles and the inside edges were kinda rough but not bad. Have the toe off by 0.5 degrees and it will destroy a tire in 1000 miles. Seen it.

Obviously an alignment would be a good idea, but it is weird to have them grouped like that timing wise. Do both of you park in the same place or anything that might subject your tires to some similar substance? I'm wondering if there is something corrosive to rubber compounds that you are parking on that is over softening the rubber?

Ok I'm going to respond to guesses: -winter heat cycling...I live in Florida so I doubt it.

• alignment - my Miata was a fairly new purchase so I hadn't gotten an alignment done yet. I do have the old numbers though. I'll post those later. As for my girlfriend's SUV, you can only lead a horse to water... Also, there have been no signs of interior-biased tire wear.

-common areas - we park in the same driveway but no unusual chemicals have been used there since we moved in last June. I have degreased both our vehicles with Simple Green and that's about the only common substance between the two.

Duh. as everyone said, when you are getting strange tire wear time for an alignment. Low pressures could come in here also. How often do you check your pressures. Once a week, once a month, once a year, never.

Do you rotate ?

I think it is because you love curves.

Have both vehicles aligned at reputable shop that will give you before and after printout. Purchase 4 new quality tires for each vehicle. Purchase 2 tire pressure gauges and use them at least once a month. Inspect tires for wear/damage when checking tire pressure/approaching vehicle. Avoid potholes and gators. Sell tires when they have 6/32 tread left to avoid disposal charge. Repeat as needed.

Has anybody mentioned toe yet?

I check my tire pressures at minimum monthly, sometimes weekly if I'm tinkering. Thanks Wawa for free air I kept the all-seasons in the 34-38psi range and the RE71Rs 28-36 so far. Again, with my girlfriend, you can only lead a horse to water... Both cars have 4 new tires. I also have new 15 x 7 rims. My Miata has since had an alignment when I got the new tires.

One thing I missed that is probably an important component are the potholes. Orlando has, IMO, the crappiest road conditions in Florida. There isn't a half mile of road without degrading asphalt, potholes, cracks, expansion joints (on roads not even bridges/overpasses), manholes that are destructively high, or the worst train track crossings I've experienced anywhere. That could influence alignment heavily. Still, why the inside of the tires? Why does right rear tire seem to be a common point? Those specifics are what bug me.

I vaguely remember orange blossom trail having some terrible road conditions. If you need tires changed, though (and sounds like you do frequently!) I recommend Tropical tire.

I_Love_Curves wrote: I check my tire pressures at minimum monthly, sometimes weekly if I'm tinkering. Thanks Wawa for free air I kept the all-seasons in the 34-38psi range and the RE71Rs 28-36 so far. Again, with my girlfriend, you can only lead a horse to water... Both cars have 4 new tires. I also have new 15 x 7 rims. My Miata has since had an alignment when I got the new tires. One thing I missed that is probably an important component are the potholes. Orlando has, IMO, the crappiest road conditions in Florida. There isn't a half mile of road without degrading asphalt, potholes, cracks, expansion joints (on roads not even bridges/overpasses), manholes that are destructively high, or the worst train track crossings I've experienced anywhere. That could influence alignment heavily. Still, why the inside of the tires? Why does right rear tire seem to be a common point? Those specifics are what bug me.

Get the alignment checked.

I mean, at least take a couple tape measures out and do a ghetto alignment check from the front and rear of the tires to the one across from it. It wont be very accurate but will be accurate enough to show you if you have a big toe difference between the two.

Another vote here for getting an alignment done.

Why are you dating a horse?

Shot ball joints, outer tie rod ends, old squishy control arm bushings, and wobbly wheel bearings all can render a perfect alignment job useless.

ultraclyde wrote:

Knurled wrote: Whoever is doing your alignments needs their rack recalibrated.

or you need to start having alignments actually, you know, done.

It's true - everyone needs a nice rack

In reply to WildScotsRacing:

A reputable shop will do a complete steering, suspension and tire inspection before performing an alignment. You will not get a perfect alignment w/worn or loose parts. The readings will change as you attempt to align the vehicle. Unless of course they use the "green is good" method.

outasite wrote: In reply to WildScotsRacing: A reputable shop will do a complete steering, suspension and tire inspection before performing an alignment. You will not get a perfect alignment w/worn or loose parts. The readings will change as you attempt to align the vehicle. Unless of course they use the "green is good" method.

"Green is good" is all too common. Otherwise known as a "Toe and Go". A proper shop will refuse to do an alignment if they find the slightest detectable movement in a single suspension part.

Based on the OP's milage, year, and unknown Previous Owners, I think he would be better off just replacing ALL of the following before getting the alignment set:

1) outer tie rod ends 2) upper and lower ball joints 3) wheel bearings 4) upper and lower front control arm bushings

This way he will be starting with zero-miles all new suspension link points. I garantee his excessive/odd tire wear will be gone for good, after getting the alignment set. Plus, he will be starting from a known data point to track his car's future suspension inspections.