I have had several cars that run better than 1.5 degrees of negative camber in the rear. Looking at my MS and comparing the front to the rear I'd guess the rears are over -1.5. Camber gain is built into suspensions so the negative value will only increase as the car lowers going down the road.
Running this much camber reduces contact patch which decreases rolling resistance. It also helps save you on throttle off over steer. Most people's normal reaction when they feel like they have entered a corner too fast is to lift off the accelerator. This causes forward weight transfer, unloads the rear and the car can swap ends. Negative camber in the rear gives more safety margin.
The down side is it wears the inside of the tire, sometimes very quickly. I've had cars that would destroy rears in 4,000 miles. I have addressed the problem by going to the lower limit of the factory recommended values for rear camber (and sometimes less) and have even had to adjust ride height to get to an acceptable number. That acceptable number is no more than -1.0 degree for me but this is a personal preference.
Has anyone looked at this? Have you measured tread wear across the rear contact patch? I'll do mine shortly and share the results. At $500 a piece, I would prefer to not be buying Pilot's on a regular basis.
