kiev
Posts: 451
Joined: Sun May 03, 2015 7:15 am
Location: The Heart o' Dixie
Contact: Website

Re: Front tire wear

Sun Aug 21, 2016 2:28 pm

It looks like you are seeing excessive inside edge wear--too much toe-in would be the culprit.

Your outside edges look full tread with no wear at all--too bad we can't adjust these things to wear evenly across the face.

These tires are so thin they want to ride on an edge rather than the center and they are twitchy when new, then after they wear the favored edge the steering tends to settle in and it doesn't feel like they are jumping around so much.
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Don
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Location: Biloxi MS

Re: Front tire weara

Sun Aug 21, 2016 3:20 pm

JoeS wrote:Comments about alignment issue?
MacPherson strut front suspension isn't the way to do it for either good handling or good tire wear - It's the cheapest way to do it on a small car, but certainly not the best. You only have control of the camber when the tires are pointed straight ahead

The struts are tilted inwards at the top and slightly aft to get the desired caster setting. The spindle is attached to the strut at the opposite angle of the inward tilt, so the wheel is cambered near zero when pointed straight ahead - Pretty much perpendicular to the road. Ok as far as that goes

Now, turn your wheel all the way to the right and look at the outside tire (drivers side) and check the camber - You'll see that the top of the tire is now tilted inward (negative camber) so the inside of the tire is going to take the brunt of the wear when the wheels are turned. When you consider that this car understeers something terrible (tries to go straight instead of turning) you can easily see what's about to happen - You'll scuff the tread off the inside of the tire when cornering hard and fast. The outside wheel takes the brunt of the cornering force and it's tire is decambered so it scuffs tread off the inside of the tire. If you check the passenger side wheel when turned full right, you'll see the opposite - Positive camber and the tire wearing the outside edge . . . . but the outside tire is going to see the brunt of the wear. Also, body roll during hard cornering compresses the strut on the outside of the corner (drivers side when turning right) and as you compress the strut, you add even more negative camber

There is no 'fix' for this - Nothing can be adjusted. The angle between the spindle and the strut is fixed and cannot be changed as the wheel turns left or right, as it really needs to be. You could dial in less caster (tilt the top of the strut forward, more toward vertical which would add positive camber when the wheel is turned) but then you're messing with other things - How hard it is to turn the wheels and whether they will tend to straighten out when you release the steering wheel so you don't want to mess with that

From an online article by JD Laukkonen "Of course, the overall simplicity of MacPherson strut suspensions also leads to a handful of disadvantages. Although it makes it easier to set the suspension geometry when performing repairs (i.e. if nothing is bent, and you bolt everything in place, then the caster and camber will both be correct), that same simplicity means that the camber angle necessarily changes when the vertical position of the wheel changes. The net effect is that MacPherson strut suspensions are typically seen as possessing inferior handling characteristics to other suspension systems (i.e. double wishbone, etc.)"

The 'solution' is a double wishbone front suspension with unequal length control arms (the upper arm shorter than the lower arm) as is found on many rear wheel drive performance cars - FWD cars almost always use MacPherson struts for space reasons - I imagine Mitsu is using them here because they are CHEAP and this chassis was originally designed as a very low buck city commuter car - In our car, struts also give more front seat legroom

With unequal length control arms you not only have the camber you want when going straight ahead, but you can also alter it as the wheel turns left or right, which gives you not only much better tire wear, but also much better handling as well

Long story short, it was designed as a city commuter car and they never considered we might like to do clover leafs at 50 MPH. Slow down and you get extra range . . . . *and* your tires will last longer too

Don
2012 iMiEV SE Premium, White
2012 iMiEV SE, White
2014 Ford Transit Connect XLT SWB wagon, 14,000 miles
1994 Miata 60K miles - Soon to be sold
1979 Honda CBX six into six

tigger19687
Posts: 547
Joined: Tue Feb 10, 2015 1:19 pm
Location: Bedford/Concord MA

Re: Front tire wear

Mon Aug 22, 2016 4:48 pm

Don't know about YOUR clover leafs, but mine here are so tight that there is no way to do more then 30/35 on it in this car. I can't do more then that in my truck .
:lol:
[size=85]- Linda
-2017 Chevy Bolt Premier Bright Blue
- 2012 Black i-MiEV (the Black jellybean) selling !!!
- 2014 Toyota Prius C, for the Son

DogMan12
Posts: 61
Joined: Tue Jun 11, 2013 5:57 am
Location: Kooskooskie, WA

Re: Front tire wear

Sat Aug 27, 2016 4:53 pm

I still have the OEMs at 27,000 mi. Running 42 psi fr/rr. The fronts are basically done, with the wear on the INSIDE. I bought another set of OEMs last fall because I thought they might get hard to find. I will put them on in the next couple of weeks to be ready for winter. Well, sort of winter. I drive my Jeep when it is really funky.
Dog Man Son
2012 iMiEV
We call it not Raspberry, but Metallic Malbec

RobbW
Posts: 397
Joined: Mon Jul 08, 2013 1:23 pm
Location: Elgin, IL

Re: Front tire wear

Wed Jan 11, 2017 12:56 pm

I am just now having all 4 tires on my Meepster replaced. Purchased her new in July 2013. She currently has 35.5K miles on her. I noticed the inside tread of the front tires wearing out quite a while ago. However, I'm only just now getting around to replacing the tires due to necessity. Got a flat tire this past Monday night after driving over some type of large metal bar in the road that was unavoidable. The front driver's side tire went immediately flat. Unfortunately, the damage was to severe for the so-called "tire repair kit" to repair. Had to have the Meepster towed to my local dealership, which was fortunately only 4 miles away. Unfortunately, I was a few months outside of the initial 36-month warranty that would have given me a free two through Mitsubishi Roadside Assistance. Oh, well. Luckily, the tow was only $75.

Anyway, Meepster is at the dealer's service department right now. They said they highly recommended that I have all four tires replaced since my tread was 3/32" or less on all tires. I mentioned that I noticed the inside tread of the front tires was nearly bald while the outside tread looked pretty decent. The service advisor said there might be an alignment issue causing the uneven wear. The dealer's service department is not equipped to perform alignments. So, he recommended that he could send my car over to their alignment shop for service. He quoted $99 for an alignment.

Other services recommended were the "rear brake drum clean and adjust" for $129.95 and the "main battery re-calibration" for $249.95. I refused both of those recommended services. Anyone know if the battery re-calibration is necessary for the warranty to remain intact? Or is this simply a cash grab by the dealership since they get so little service/maintenance revenue from iMiEV owners?
Clear Skies,
Robb

EV: 2012 Mitsubishi i-MiEV SE, Raspberry Metallic, Premium Package - Purchased 07/11/13
PHEV: 2017 Chrysler Pacifica eHybrid, Bright White, Platinum Package - Purchased 05/01/17

PV1
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Re: Front tire wear

Wed Jan 11, 2017 4:52 pm

Calibration is a cash grab (we can do it for free. Go below 2 bars and charge to full). A can of brake cleaner is pretty cheap, too.
"Bear" - 2012 Diamond White Pearl ES with QC - 2/21/2013
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