I was test driving the Audi A4 3.0 quattro and the Volvo S60 2.4T AWD at the same dealership, and the salesman told me that non-turbo engines lose 15% of its power for every 1000 ft of altitude while turbo engines have the same power regardless of altitude. Anybody heard of this before? This concerns me, since my daily commute ranges from 5300-7400 feet elevation. It makes sense to lose some power, but not that much!?! And why only the non-turbo?