Owner is complaining that the SUV is wearing out tires in less than two years of slow driving on windy California one-lane mountain roads.
Why?
I think a slightly overinflated tire wears best on mountain roads.
There is more wear traveling upward especially with a heavy vehicle such as an an SUV. In my estimation its the added friction rather than cross-winds etc., that eats up tires in mountains. If you drive fast and fast uphill (!) they will wear fast on any car, super-fast on a heavier vehicle.
I know I don't make it much past 30k miles with Michelins driving a Subaru Impreza. Overinflating helps. 38-39psi is what I like. I do a lot of high speed driving on I-80 between Reno an San Francisco.
There isn't much you can do besides maybe buying a tire with the hardest compound, highest rating, but these type of tires are not the best in inclement weather. Pump them hard and accept that you will have to pay more for that type of driving.
Basia
Let me add, out of two identical tires, mounted on same weight vehicle on same axis theoretically the fatter tires should last longer. Contact pressure is less and friction is distributed over a larger area.
Basia
On Wed, 14 Dec 2016 21:58:20 -0800 (PST), Basia advised:
Hi Basia, Thanks for hazarding a guess since it's a tricky question without much detail other than the tire size and the type of road.
This driver drives slowly, so I'm surprised the wear is so bad, but it is, and it's even (so it's not alignment most likely). It was aligned at the last tire change and nothing needed to be changed (so it was free).
It's interesting that you too don't get further than 30K miles on your Subaru Impreza. If the UTQG traction number is 300 for your Michelins, that would be about the same as she seems to get on the Toyota, which is 10K per
100 points on the UTQG scale.I like the idea of overinflating to around 40 psi (the tires can handle
65psi I think) so I may suggest that as I'm mounting and balancing her tires at home using Harbor Freight tools.On the one hand, you'd expect *more* tire wear on the thinner tire because the same amount of vehicle weight has to be carried by less of a contact patch.
But from the other hand, there is less friction in the smaller tire.
SO I wasn't sure how the wear would differ between a P225 and a P235 where the P225 is stock but she has had the P235s for a long time (multiple sets).
Fatter is theoretically better but circumference also plays a role. Bigger tires make fewer revolutions per mile. So I'd say fatter, bigger, pumped harder is the solution.
Basia
My guess is that the tire with the hardest rubber compound will last the longest. That soft stuff is not durable!
On Wed, 14 Dec 2016 22:09:57 -0800 (PST), Basia advised:
That's what I was thinking which is that force equals pressure per unit area, so given all the same things except the size of the contact patch, a smaller contact patch tire should wear quicker.
However, a smaller contact patch should have less friction on turns, so, I was wondering which wins in the end.
It probably doesn't make a difference in reality, but then, why do they even bother with wider tires?
On Wed, 14 Dec 2016 22:23:02 -0800 (PST), Basia advised:
I ran a circumference calculator
So, the smaller tire will revolve 15 revs more per mile, which, I guess, all by itself, must cause 2% more wear to the tire.
On Wed, 14 Dec 2016 23:10:08 -0800 (PST), dsi1 advised:
The old tire was a treadwear of 700 I think, while the new tire is 460 as I recall (I have to look it up).
The one with the harder rubber wears best on mountain roads, and is likely also the one that handles most poorly on mountain roads.
If it were me, I'd go for the better handling over the longer wear, but that's just me.
--scott
The OP is more concerned with tire wear than handling. And anyway, my drivi ng skills are so refined that I can actually drive on mountain roads with a ny kind of tires without falling off the side. I suppose some folks might n eed all the help they can get though. :)
On 15 Dec 2016 10:16:49 -0500, Scott Dorsey advised:
Hi Scott, What you said makes sense in that the harder rubber should wear better on twisty mountain roads, but the fundamental question is how do you tell from the specs which has the harder rubber?
I guess the UTQG number tells us which is the harder rubber, which is that the 700 Treadwear should be harder than the 460 Treadwear rating.
Is that your presumption too?
On Thu, 15 Dec 2016 10:30:50 -0800 (PST), dsi1 advised:
Driving is a funny skill in that almost *everyone* rates themselves as a 10 out of 10 (just like you just did) when, in fact, a bell curve has to be the case, so the vast majority of us must be *average* drivers (about 5 out of 10).
It turns out that driving is so *easy*, that everyone thinks they're experts at it, which is a classic Dunning-Kruger response from the hoi polloi.
The proof that driving is so easy is that almost every 17 year old can get a license, and almost everyone survives 50 years of driving without a single accident in their entire lives or ticket or mishap or even hitting an animal or accidentally going off the road.
But the fact that almost everyone thinks they're a driving genius (when they're actually not) is not the topic of this thread.
The fact is, in this case, as you noted, the question isn't about handling. The question is about tire wear (which you correctly noted).
I think the answer to the question is this simple:
Did I summarize the consensus from the team accurately?
I have not completed the team analysis at this time. All I know is that if you need special soft compound tires to drive on a mountain road, you probably need to work on your driving skills.
On Fri, 16 Dec 2016 08:31:41 -0800 (PST), dsi1 advised:
How did you miss the point completely? First off, it's not my vehicle so my skills don't count. And I'm not gonna change the driving skills of a little old lady.
But even so ... you completely missed the point (entirely). What do "driving skills" have to do with tire wear anyway?
The wear is from the twisty roads. Not from the driver's skill on the twisty roads.
Or do you know something that nobody else knows?
One thing about me is that I never ever miss points. My point was that I can drive on mountain roads on any kind of tires. I don't need soft compound tires. The point you missed (entirely) was that I was addressing another poster, not you.
On Fri, 16 Dec 2016 11:13:51 -0800 (PST), dsi1 advised:
Oh. Ok. mea culpa
BUT their traction is excellent. Driving my friend's S2000 (with the $2K/set soft tires that last 20K miles) down a mountain road was the most fun I've ever had in a car, even with all the botched shifts because I couldn't tell what gear I was in and how to get to the next one :-)
You pays your money and takes your choice!
I suspect that we ALL possess similar skills.
My GPS tried to send me off the edge down a mountain TWICE. A good dose of skepticism is always useful.
We all do but falling off the side of a mountain is a good indicator than y ou're probably not as great as you think. My friend's ex drove off the side of a mountain and landed on the riverbank. She clawed up the side of the m ountain while carrying an infant. Another car drove off the same place and landed on her car. The couple in the car was carried off in the river and p erished.
You should never trust those things!
MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.