I had a P85+ today as a loaner and while I liked the slightly better pickup compared to my normal 85, the 21 inch wheels and performance tires come at the cost of higher energy usage. It's more than just subtle, it's somewhere around 7-10% more. I drove the same roads in very similar traffic in both cars and the difference was obvious. Tire noise is also worse. It was actually the first thing I noticed when I started driving. Much more noisy tires compared to my 19 inch. The first moments I really though, 'what is that noise?' Los Angeles' bad roads make 19 inch wheels a wiser choice as well.