I've always used Mobil 1 in my new cars starting with their first oil change. I just bought a 98 AWD R with (now) 63K miles. Should I switch to synthetic this late in the game or just stick with the regular oil? What threats, if any might it pose? The car has been serviced regularly by Volvo, so I know it's been properly maintained and the oil changed at the proper intervals. At some point in the next 6 months or less I'd like to go with a performance chip and dual exhaust if that makes any difference. Any enlightenment on any of these points is appreciated. Thanks.