Alignment Specs

[e92328i998]

Is there a preferred alignment spec that focuses on even treadwear? When I had my e70 there was a pretty well documented thread by a guy named ARD. I just picked up an E93 and will probably keep all seasons (Conti DSW) on it, but looking through the maintenance history, there were a lot more alignments than I am used to with a car.

[Thumbie]

Great purchase! e93s are undervalued.

Just go with the factory alignment specs.

[e92328i998]

Originally Posted by Thumbie

Great purchase! e93s are undervalued.

Just go with the factory alignment specs.

Isn't that a pretty wide range though? Are there preferred figures within the range?

[Thumbie]

Yes but as long as you are in that range, any variations within are essentially splitting hairs. It's also difficult for a shop to get both sides precisely the same 1/10th of a degree.

Ask for as much negative camber as you can get up front, that the factory range allows. It will be more fun to drive.

[powerbait]

I have run with the front pins pulled for more camber, but would have my toe set at 0.05 (the minimum in spec) each side to minimize front wear, but still have some toe in for stability, and I'd have the rear set right in the middle of the spec 0.08 - 0.09. While trying to get the camber as even as I could on each side. I've had great luck setting it up this way. There is a local shop that lets me crawl under with them and they'll set it to exactly what I want, not just "in the green."
I recently added Dinan fixed camber plates and got the front camber to -2.5 and the toe at 0.05 on each side. One side I could get an additional 1/4 deg negative but backed it off to keep them even.

[TboneS54]

Originally Posted by DrFerry

The O.P. is asking about alignment specs that focus on "even tread wear". Over time, -2.5 degrees of negative front camber will yield inside shoulder tread wear when used on the street.

Increasingly so as toe goes away from 0. With neutral toe, the inner tread wear won't be bad at all even after many miles.

[smokinjoe64]

More for comparison...

My Set-up & Results

Suspension

• Bilstein B16 coil over kit w/EDC; lowered ride height within B16 kit config capability
• 100% Refresh & upgrades - Arms w/mono-balls, links, bushings

Use Case & Handling

• 90% Spirited street; 10% autocross
• Steering - Tracking spot on; sharp, predictable turn-in/performance
• OE spec 18" tires & wheels; Michelin Pilot Sport

Tire Wear - After ~20K mls & counting 'normal wear'; no cupping...so-far so good

[M3SQRD]

Originally Posted by TboneS54

Increasingly so as toe goes away from 0. With neutral toe, the inner tread wear won't be bad at all even after many miles.

Yep. Incorrect toe causes more rapid wear on the inner edge of the tire than camber does. -2.5 deg of camber will not show much inner edge tire wear until the tire has been used for several thousands of miles. Incorrect toe can destroy a tire after only 2-3k miles.

[e92328i998]

Got some new tires put on last week and have an alignment scheduled Friday. Discount Tire wasn't willing to do one on a BMW but did give me the attached readout. Doesn't seem to be too far out of whack.

Tires are Continental DWS06+ in 255/35/19 and 275/35/19. Looking for good even where (when possible with offset) and longevity without compromising performance (if possible - but remember these are all seasons and a vert so not tracking the thing).

Thoughts

[Thumbie]

Just bring it to an alignment shop and show them that sheet. Ask if they can fine tune it.

Most of us on this forum favor sharper handling over economical treadwear. So the specs we recommend will be more aggressive than what you are looking for.

Even the factory alignment specs could be considered aggressive when compared to a prius. but they will be the best blend of handling, comfort, and treadwear.

[e92328i998]

Turns out the alignment check I got done at discount while getting tires was crap. They didn't have the wheel centered which threw everything off. Took it to a place in town recommended for hitting numbers (weirdly enough the Volvo dealership). This was before and after.

[M43ver]

To maximize tread life you’ll want to run the low end of the front and rear toe specs. If you have camber plates, set the front to -2.0 deg, and set the rear to -1.8 deg. You might need to add camber plates if you don’t have them if the left and right camber settings are far off from each other. The cost will be returned in terms of increased tire mileage. These specs will numb performance but will extend tire life.

[THEROK]

Erewhon/Equinox mobile with the occasional jaunt to the Angeles Crest.

Vorshlag camber plates + Ohlins RT. 265 18s up front, 295 19s in the rear.

Drives glass smooth, dead straight at 90 mph and feels lighter on its feet.