Forums

Tire wear

Tire wear

It hits me as strange that some big attractions of the Model S are the drastically reduced number of moving parts, the simplicity and durability of the drive train, the pathbreaking efficiency, minimal repairs and maintenance; AND YET everybody seems fine with tires lasting only 10k miles or so. Am I right? I'm hot on the Model S and will take delivery in 2014. But I'm accustomed to tires lasting a minimum of 50k to 80k miles, and I have experienced even better wear on many of my cars over the decades. For such an efficient, long lasting, and low maintenance car I would expect tire wear also to be right up there. What am I missing?

jed-99aggie | December 8, 2013

I agree generally with Smith 1's comments.

My prior car was an Audi S4 (avant) where I too experienced rapid inner shoulder tire wear (<10k). GVW listed ~4,000 lbs. The alignment was in spec. Soft performance tire rubber, vehicle weight, camber spec, and minimal sidewall height contribute to this wear. I do not believe this to be isolated to the Model S.

The superior handling of the 21s comes at a price (friction is present every time the go pedal is depressed AND released for regen/braking). There may very well be more than price and styling considerations for why Tesla offers the 19" option. As a daily driver in our household, the 19s have been more than adequate.

@ aliiranitehrani,

In reading your post, I was thinking you may have overlooked the vehicle weight compared to your other performance car comparisons. Then you drop in your Cayenne in the comparison. Unless I am mistaken, the Cayenne employs an AWD drivetrain, thus distributing the traction duties of acceleration of the 5,300 lbs beast to four tires, not just the two as is the case in the Model S.

lolachampcar | December 8, 2013

http://www.teslamotorsclub.com/showthread.php/18678-19-quot-and-21-quot-...(informal)-Survey

I stopped updating the first page a while ago but it is clear that there are a lot of 21s out there getting reasonable (15k miles) wear and WHr/mile does not seem to be the underlying driver.

MichaelN | December 8, 2013

Has anyone tried Hankook 21"s - I am going to look into to them - highly rated, build many racing tires, usually less expensive - Sears has 245/35/21 for $188 (tread wear grade 280 - tread wear grade for the Conti's is 340)- just wondering? I would expect them to perform well, but anyone with experience?

dortor | December 9, 2013

We also have to keep in mind regen braking as additional "load" on rear tires...during regen only two tires are used to slow the car - the rears

This has got to cause more wear than other cars...

Interesting to calculate the "cost" of these regen watt-hrs vs. the tire cost - my gut tells me regen watt-hrs are very very expensive...

aliiranitehrani | December 10, 2013

jed-99aggie: you're right, the Cayenne does incorporate AWD and that must have helped with tire wear. I only changed one set of tires in four years of ownership! Less than 12 months, here I am whining about Tesla tires! :-/

But my point was not about even and ordinary tire wear. The outside of my Tesla tires are in good shape, the inside are on chords! Driving conservatively on the Model S, I think I could get 20K+ miles on the Michelin PS2 IF it wasn't for the uneven wear, and that's what's upsetting...crappy wear, even with two tire rotations.

dortor brings up a another good point though. Aggressive regen must be peeling away layers of our sticky compound. I know I'm often surprised how quickly regen is able to slow down this massive 4,600 lb tank.

Overall, the message many us of on this tread and other treads are making is: <10,000 miles on ~$2,400 worth of tires is excessive...something that wasn't really part of our initial ownership cost calculations. I think our posts are more out of frustration for lack of planning than anything else.

Whether you're coming from an SUV, a sports car, or a big body S Class and 7 Series...the 21" tire wear story is a surprise to many of us.

The 19" tires seem to be wearing much more evenly. Whether that's because there aren't many of the torquey P85s with 19" tires...or because the 19" are usually sold with the 60s and standard 85 models that have less overall performance (and less aggressive drivers), I dunno.

The reply I've gotten from Tesla is I shouldn't expect no more than ~10K miles from 21" Michelin PS2 tires. This has really gotten me thinking about downgrading to some nice 20" wheels and matching them with some Michelin Primacy MXV4 tires. Hopefully that will save me some money in the long run and put an end my bitching.

Overall, it's an inconvenience to a brilliantly engineered car! Go Tesla! :-)

lolachampcar | December 11, 2013

There are two changes I would make to a new P+ purchase.
I would get coil instead of air and set my ride height to the desired level (along with camber for the lower ride height in the rear).
I would order the 19s and then pick up a light weight set of 20s with the expanded availability of rubber (PS2s). Of course this means buying a spare rim (or rims if you uses staggered widths) because aftermarket rims are seldom available as long as I own a car. This approach provides better value and more flexibility.

WRT getting the most out of your rear tires, I've owed several cars were there was high rear negative camber but where I did not drive them enough each year to warrant doing a fix. For these cars I just rotated tires across the back of the car.

The above requires that you understand and are comfortable with the idea of running the "inside" on the outside. Common sense tells me I would rather have one less rain groove with 85% tread depth on the inside than one more groove with 30% tread depth. Discussions with numerous tire engineers dealt with the technical concerns about doing this for me but we must all make our own (informed) decisions.

lolachampcar | December 11, 2013

and the above rotation method would usually extend 10K tire to 15K tires.....

Bighorn | December 11, 2013

It's not quite 2400 bucks per 10,000 miles because the fronts are going to last at least twice that, I think.

CalDreamin | December 11, 2013

At 12K miles on my S85, the 19" OEM Goodyears are wearing evenly across the tread. They have a lot of life left in them.

Luclyluciano | December 11, 2013

I think the fact that the 19" rims wear evenly rules out the regen reasoning. I also think the fact that the 21" tires are wearing out on the inside only, also rules out the regen, driving hard, softer rubber, low sidewall sport tires etc. Tires wearing unevenly to the chords is an alignment problem either from design or impact.

There is no use saving money on gas then needlessly blowing it on rubber, great car or not that would piss me off.

Brian H | December 12, 2013

cords

chords applies to geometry and music, not tires!

lolachampcar | December 12, 2013

ah, the benefit of not having bought the car to save gas :)
Sounds a bit like pandering but I was one that actually bought the car because it is the best car out there (that just happened to be electric). Sure, the electric drive allowed for so many of the design decisions that makes the car incredible in addition to being directly responsible for the spaceship type speed control. So I guess I did buy it "because it was electric" but it sure felt like I was buying it because it was an awesome car.

WRT tires, I come from BMWs so managing rear tire wear on cars with high negative camber is second nature for me. I do not accept it, but I do accept that I have to manage it.

It seems the question for most is who should be responsible for managing tire wear? Is it the owner's responsibility to understand the car's design and react accordingly or should Tesla make some changes. The answer and reaction seem to differ on were you come from (car wise). Although very different in impact (pun not intended), this seems similar to the ground clearance/road debris discussion. If you've always driven things with low ground clearance, you instinctively know and manage the risk of road debris.

I only know where I come down personally but, tending to be a bit of an odd one on things like this, I'm not sure my approach is, or should be, the "correct" one.

pramod1969 | December 12, 2013

I agree with above statements. No regeneration/camber theories make any sense for excessive rear tire wear.

I hope the new alignments offered by Tesla SC will make good impact on 21" tires but I am not very hopeful.

If Tesla really fixed the alignment issue for newer vehicles without recalling older production vehicles, that would make lot of 21" owners very upset.

Brian H | December 12, 2013

lola, have you heard of the new "camber adjustment bolts" some are being offered? What's your assessment?

lolachampcar | December 12, 2013

I have no first hand experience with them but have been told they are good for a few tenths of a degree and used solely to bring out of spec. (absolute or cross camber) values back in. I do not believe they can bring an air car's camber down to a coil spring car's camber.

AAviator | December 12, 2013

So the 19s don't wear funny but the 21s do, But apparently not all 21s.

So It has to either be a block of cars that came off the line mis-rigged or else it is something that us unique to the cars.

Since the 19s don't seem to have the problem, I am guessing that there is a problem with the air suspension. Interestingly, now that the car is not lowering itself at high speed I have would bet that this problem might get better.

I am guessing that the coil spring cars do not have as much of a problem. Furthermore, I have been driving regenning cars since 2004 and never noticed anything unique about tire wear from regen...

Cheers
Andrew

lolachampcar | December 13, 2013

Coil spring cars ride higher. Air spring cars can maintain ride height when the car is heavily loaded by simply adding air to the bags. Coil cars have to leave room for the coils to compress when the car is fully loaded and thus must start off higher if they are going to end up in the same place as air when the car is full.

MS' rear suspension has "camber gain" built into it. This means that negative camber increases as the wheel travels up into the fender well. I believe the coil and air cars use the exact same suspension (apart from the damper valving and obvious spring difference) thus the air car's lower Standard ride height has the wheels further up in the wheel wells. Put differently, camber gain means air cars will have more negative camber in the rear. This is confirmed by Tesla's alignment specs which detail a lower ride height for air cars combined with more negative allowable rear camber range.

WRT rim size, the 19" rims allow for more tire side wall and are generally narrower than the 21" set up. These two factors allow the contact patch of the tire to better conform to the pavement, be more evenly loaded and thus wear more evenly.

Lastly, your point about some 21s doing ok and others not is the real puzzler. A hand full of owners have documented before and after alignment specs where they had toe OUT in the rear of the car. This will dramatically accelerate inside shoulder wear when combined with high negative camber. It seems to be the only possible smoking gun so far as driving style and regen do not appear to be common factors (see tire wear survey here or on TMC).

bansal | December 16, 2013

I have a P85 with 21" wheels and 8600 miles. Just found out that the rear inside tires were "corded" and need to be replaced immediately. The front are not far behind. What a disappointment for an otherwise spectacular vehicle. Whatever was saved in gas has certainly been now spent on tires and will continue to add up. Hopefully, Tesla can find a fix for future vehicles.

pramod1969 | December 22, 2013

Just had wheel alignment done for 21"" with bolt. Finally all the alignment numbers are in green. Costed $170 in SC and I hope it will be worth it if it keeps my tires to stay longer on my car.

MichaelN | December 22, 2013

At 13000 my 21's have wear showing on the inside, outside like new - wanted to dismount and remount on the opposite wheel, but wear too far gone so the tire shop does not want to do it - on the next set I will rotate at 4,000, remount at 8000, rotate at 12,000 and see if it makes any difference - hope to see 16-20,000 - I did find a set of Hankook tires (Ventus V12 EVO K110 96Y) with the same specs as the Conti Extremes, a lower wear rating (280 VS 340 so maybe not as long lasting)at a price of $165 each (plus tax and shipping of $50)and they have the same ride comfort rating, plus they are listed as all weather and have an aggressive tread - I am going to try a set (like the all weather rating for the 21") as I do not ricky race the car - go to ONLINETIRES.COM and check them out -

pramod1969 - where did you take your S for the wheel alignment?

lolachampcar - how can one buy the camber links from your TMC post?

MichaelN | December 22, 2013

my email is manovak123@gmail for anyone wishing to discuss the subject further -

lolachampcar | December 22, 2013

Michael,
I made my own links. I keep getting asked the question so I think it is time we find a Ca tuner willing to make up links and maybe even install them. It takes me about an hour and a half to change out the links which includes pressing the stock bushing out of the original links and pressing them into mine.

I did try a slightly longer link to pull even more camber out (went from 0.210" longer to 0.250" longer) but found there is not enough toe adjustment for that long an arm. I'm going back to the 0.210" links this week as I prefer to run near zero toe (just slightly toe'd in) for range and tire wear reasons.

Any competent tuner shop could have a reasonable batch of arms run. They are a simple water jet cut from 1" aluminum plate followed by final machining to establish the bushing hole diameter, center to center distance and add the ride height ball attachment point. Anodize and you're done. There is no reason why a run of ten sets could not be done such that they are less than a single PS2 to the buyer and still have 50% margins.

I would make them but I am not in a position to accept any liability exposure :( It's sad but that is what this world has come down to.

lolachampcar | December 22, 2013

Oh, the stock Tesla arms are an extrusion. I looked into it but a 12" diameter extrusion die is cost prohibitive.

Also, the longer 0.250" arms would work just fine if coupled with longer toe links.

MichaelN | December 22, 2013

lola - what area of CA - I live in the Inland Empire and know a shop who could do the work, but liability will be an issue for him also - your right, too bad - I guess I could make them with him looking over my shoulder - I saw on line your various diagrams but can't really make out the details - you mention pressing out the bushings, is this something you do regularly, back and forth? - can the bushings be purchased separately, so as to have a set in the originals and the new ones?

pramod1969 | December 23, 2013

Michael, I took my car to Orlando SC. I am sure all service centers can order the bolt for rear camber adjustment. Only time will tell if it works to keep the alignment but I will go for frequent checks.

lolachampcar | December 23, 2013

The bolt is a necked down stock bolt that allows more "bolt slop". The SC then bias the upper link to the negative camber side of the bolt slop and tightens the bolt down. I think this is good for a few tenths of a degree.

My 0.210" arms were made to reduce negative camber by one degree (which they did +/- .1 degree).

The only reason I mentioned Ca is because a lions share of the cars are in Ca. Being able to have the work done by the same shop improves margins for the shop and thus incentive to do the project.

I had press tools made to properly fit and hold the bushings/arms. It is easy to change the bushings with the proper tools. As for ordering bushings, I WISH. Tesla buys assemblies from their vendors and thus there are no bushings to be bought. I ordered a stock arm from Tesla when I did my original work to verify geometry.

wbrown01 | December 23, 2013

I have 25,000 miles on mine now. Last time I was in Tesla service said I was low and will need tires soom. They have been rotated only once.

wbrown01 | December 23, 2013

And they are 19in

Pages