I want to stand my wheels straight up
 

I'm putting on new rear tires for my 2000 S. The old one are worn out on the inside because of the heavy negative camber. My main use for the car is scenic driving at moderate speeds and I'll never use the car on a track. Ultimate grip is irrelevant to how I use the car but I definitely enjoy the nimble feeling and responsiveness of the car even though I don't drive very fast.

So my question is does it hurt anything to stand the rear tires straight up? Will it make the car less nimble or responsive?

Are you asking whether you should change the suspension settings to chase some better tire wear? If so, I vote NO.

When was the last time you had an alignment and how did you get the heavy negative camber? Based on your description of how you drive, normal specs would be fine. Some people have shops adjust for track use, but that shouldn't be necessary for you. Boxsters are very easy to knock out of alignment.

You can adjust the rear camber to as neutral as it can get but the nature of the suspension geometry is designed to provide maximum grip which also means tire wear. Unfortunately you can't do much about that.

Yes you can and of course you know the compromises. There are adjustments just ask to be as close to Zero camber as possible. also check for worn out bushings

Yes you can go less negative for less tire wear on the street. I have no idea how affects your handling as its dependent upon the cornering loads you get with your type of driving. You have to feel it or get some test data or go with someone's set-up

I am trying to figure out the same thing: how to get the optimum tire contact patch for the driving I do. For me this likely means more negative camber to deal with track. cornering loads...especially on the front tires

This is easy. Ask your alignment shop to set the camber as close to zero as possible. The shop will likely say that this is not within Porsche spec. Tell the shop that you understand that this is not within spec but that you want it set up this way. This will "stand up" the tire on the street and give you more even tire wear across the tire in day-to-day driving.

The downside is now when cornering hard, most of the cornering force will be placed onto the outside 1/3 of the tire rather than onto the center of the tire. This will reduce your cornering grip but won't otherwise affect the handling or ride - turn in will still be responsive, you just won't be able to corner as hard as with the stock alignment setup.

For anyone tracking their car, they want to do the exact opposite and set up the alignment with as much negative camber as possible. This will place the force on the inside of the tire during street driving but will keep the force on the center of the tire when cornering extrememly hard on the track. It is also important to set air pressures in conjuction to the alignment on the track to keep force on the center of the tire and not on the outisde 1/3 of the tire.

If you track a lot and get pretty good, you may find that you are still running more on the outside portion of the tire despite having max negative camber and proper tire pressures. The next step at this point is to either lower the car which will alter the suspension geometry in a way that increases the negative camber or install adjustable (GT-3) control arms which allow additional camber adjustment than the stock solid control arms.

There will be an added tendancy to snap oversteer.

The original poster specifically said he does not track the car, nor does he drive it aggressively.

If you're just going out for Sunday drives, I can't see any general everyday issues with doing what you're considering. The tires will wear more evenly but your handling will be affected. I think the only time this may be of major concern to you is when making emergency maneuvers (swerving and such) on the road.

Agreed, the times when you most need a warning, it won't be there :)

I have pretty even wear on my rear tires. I'm not sure what my alignment specs are though. I don't track the car, but do drive it as hard as I can get away with on the street and don't even begin to push the limits of the car.
I'd recommend you take it to someone who knows and is experienced with Boxster alignments and let them know your driving style and tread wear concerns and see whatthey recommend.

I would leave it alone.

+ 1...

however, if you lower the tire pressure perhaps by 2 or 3 psi, the rear tire will wear more evenly

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Thanks for the replies. I think I'm going to make the change to zero camber and see how it feels. I can always put it back if I don't like it. BTW, the new Kumho rear tires are very smooth & quiet.

Exactly my thinking, sir. I can appreciate the setup of the car, and the brakes, when it comes time to dodge the road-going idiots and random debris that shows up on the road. Dodging exploded semi-truck tire chunks at 70mph is never fun, and would be even less fun if the car feels like spinning and sliding.

To Dale_K, if I can make a suggestion: Though it's more involved, you can have the tires swapped from left rim to right rim for more even wear. Since our tires tend to be directional and can't be rotated by just swapping the wheels from one side to the other, this is a (more cumbersome but effective) way of accomplishing that even wear. You're still doing the same thing, getting the tire on the other side of the car, but you're doing so by removing it from one wheel and replacing in on the other.

Depending on how often you drive the car, say 5000 miles/yr or less, you could just have this done once every year and the tires will wear very evenly across the whole of the tread.

Kumho was the only tire I could find in 13" for the Fiat. Granted it is the solus, a passenger tire, but it squeals like a pig at a rodeo if you press it in as corner. The old xzx michelins didn't do that.

The UHP all-seasons that Kumho makes that fit the 17s on a 986 are a great deal, and I imagine their summers are even better. I wouldn't compare them to a passenger car tire. The ones I'm referring to have a great, quiet, smooth ride, and put the OEM Pirelli summers to shame in everything but grip being an all-season. The car that they're on is slowly becoming a fair weather garage queen (a shame IMO), but those tires rang in at $300 or so less, installed, than my Michelin Pilot Sports that get driven much more often, and I consider the Kumhos a very close alternative in terms of bang for buck.

They ride like bedroom slippers on the highway, I'll give them that.