Today I had a service visit to a well-known dealer in the area that is one of the top Corvette sellers in the country. At 1100 miles it was my first service to perform three tasks: Software update, free oil change, and an alignment check.

I would like to get some opinions on the state of the car's alignment based on the printout I received. To put this in perspective, my C6 alignment was out of spec from the factory and I noticed that Motor Trend magazine recently tested a Z06 that had its alignment so out of spec from the factory that it adversely affected performance. Because of my expressed lack of confidence in BG's ability to do it right the dealer agreed to check it for me.

The printout I received is shown below and I would like some opinions on whether it would be advantageous to pay a reliable shop to adjust toe and camber closer to zero for all four wheels. At this time the alignment is in spec, but I'm concerned about long-term tire wear. I've always thought that the toe adjustment was the most critical in this regard and it is close to zero for both front and rear, but camber is near the limit on two wheels.

 

With 1100 miles your car's suspension has had a chance to break in and settle a bit, not much more is likely. As you can see all your numbers are within the green range. If anything, they favor good tire wear over handling. Unlike previous base Corvettes the Stingray calls for negative camber. Factory camber spec is 0.5 degree negative at all 4 corners, plus or minus 0.6. You have a bit less than -0.5, favoring tire wear over handling. Factory spec for total toe is 0.20 front, 0.0 rear, plus or minus 0.2. You are very close to spec, 0.23 total in front. With the C7's negative camber you need some toe in in front, otherwise the front tires will wear the inside shoulder, so don't set the front toe to 0.0. Note that this is for street tire longevity. For max handling you'll want more negative camber, less toe.



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Your front wheels have a bit too much toe-in. I just had mine set at 0.10 degrees total toe-in. The left front camber is nearly zero on your sheet while the passenger side is about -0.6. No reasons for the difference. You should have some negative camber in all your wheels, depending on your driving habits. If your driving includes mostly light performance style, mostly straight line, no hard cornering than you will do well with about -0.5 negative cambers.
I set my car up for intense cornering as I live surrounded by beautiful winding canyon roads. I placed all my cambers to -1.3 degrees negative. If you track the car, the factory recommendations are for -2.0 degree negative. Probably more if you autocross. I have both front and rear toes set to 0.10 degrees total toe-in. I found that when I had my rear toe at zero the car actually had a tendency to toe-out under heavy cornering, giving me a sense of oversteer in the back. I prefer not to have that sensation, particularly in high speed corners.

BTW - as I received my new '15 Stingray from the factory the front wheels had negative cambers but, the back had 0.7 and 0.8 degrees of positive camber. In only 700 miles it visibly wore the outside thread block on my car. Not sure how they managed to let a car go with THAT out-of-spec rear alignment...?

 

Some of the issues with your alignment have already been pointed out, but there is more. Sure enough, camber should be set up for your style of driving with slightly more negative camber in the front, typically. For normal combined highway and mountain road driving, I have mine set at -0.7 degrees in the front and -0.5 degrees in the back. I'd recommend no further off, side to side, than about 0.1 degrees, preferably reading exactly the same, side to side. A good all around setting for toe in, both front and rear is 0.10 total.

Now here's some more important info. Toe should be set and spec'd for each wheel, not just total as in your printout. Thrust angle should be 0.0 degrees and that depends upon the rear toe being the same on both sides -- 0.05 degrees toe in on each side yields your total of 0.10 degrees.

Now the issue of caster -- not even shown on your printout. The factory spec is +7.4 degrees +/- 0.6 degree for the front. The rear caster, however, is spec'd at 0.0 degrees +/- 0.8 degrees and failure to get this correct can cause some fairly negative handling issues. There is a special tool set used to measure rear caster and many shops are not even aware of the requirement. Setting the rear caster is new for the C7 Corvette and was not spec'd for C6s and earlier. Failure to monitor and adjust rear caster while adjusting rear camber can inadvertently cause the caster to end up out of specs -- and neither you nor your alignment shop will likely be aware of the issue.

I would locate a shop that has the angle gauge and the GM adapter to do the rear caster alignment. Tell them about the type of driving that you do and the importance of better handling versus tire life (or vice versa). A good shop will align your car much closer to optimum specs than the current settings and custom tailor the settings to your driving style.

Good luck with this.

Ernie

 

I thank all of you for the concise, detailed responses. The main question is to maximize tire wear in a practical way should I have the wheels realigned? IOW, if the current alignment will cause the tires to last 1000 mile less than an ideal situation it probably would not be worth the $100 (or whatever) to have the work done.

My feeling is that if set for best tire wear the car will handle better than 99.9% of the cars on the road. Set for best handling within the acceptable range maybe 99.95%, translating into maybe a fraction of a G in cornering ability. My car will never be tracked, so max cornering is not a priority if it means any meaningful decrease in tire life, which it obviously will.

Here's what a gather from your replies:

• Ideally set toe to .10-.20 on front and 0.0 on the rear with both near equal. Camber should be near zero or slightly negative on all four wheels, let's say 0.0-0.5°.
  
• Thrust angle should be 0.0° with rear toe equal on both sides.
  
• Caster: +7.4 ± 0.6° front, 0.0 ± 0.8° rear. Shop should have angle gauge and GM adapter.
  
• Make special note to monitor and adjust rear caster while adjusting rear camber.

The printout given me yesterday was much less detailed than the one I received on my C6 two years ago from the same dealer. It showed the status on each wheel, including caster and thrust angle.

I'll probably visit a shop today for discussion only, armed with all this good info you guys have provided. They specialize in frame and wheel alignment.

 

Factory specs

 

Saved. Thanks.

 

A few more comments:

I would tell your selected alignment shop that you want specific numbers instead of a range. Given your desire to favor tire life over getting every last bit of handling out of the car, I'd recommend the following:
Front Caster - left: 7.4 degrees; right: 7.6 degrees (see note 1 below)
Front Camber - left & right: -0.4 degrees
Front Toe-in - left & right: 0.05 degrees (for a total toe-in of 0.10 degrees)

Rear Caster - left & right: 0.0 degrees
Rear Camber - left & right: -0.3 degrees
Rear Toe-in - left & right: 0.05 degrees (for a total toe-in of 0.10 degrees -- see note 2 below)

Note 1. You'll notice from the spec sheet supplied above by "sycraft" that a cross camber of 0.3 degrees is specified. This is to compensate for crowned roads and the tendency for the car to drift to the right and is a new C7 spec change for 2015. I prefer to offset front caster instead of camber, with a bit more caster on the right, to accomplish the same thing. You can discuss this with your alignment tech, but most will probably favor offsetting caster to compensate for crowned roads.

Note 2. Having a slight bit of rear toe-in (as opposed to setting it at 0.00 degrees) will help "settle" the rear of the car while cornering quickly. I prefer the slight toe-in.

Note 3. And just as an aside, my car is set up exactly as I'm recommending to you, except for camber. Mine is set at -0.7 degrees in the front and -0.5 degrees in the rear.

Ernie