I have the 4.8 with the 20's (Dunlop). I love it. Just a word of caution, the front tires will wear fairly quickly and you will get feathering of the tire at the edges. They probably will not last long. I have 17,000 KMS on mine mostly hiway I may have to replace the fronts next year. I do like brisk driving, but by no means am I overly aggressive.

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2013 BMW X6M-current
2013 Audi S4-current
2007 BMW X5 4.8i (E70)-sold