I've looked at the differences between these two oils and not being too knowledgeable in oils other than I've used synthetics since my car had 50,000 miles. I'd like to know if one would work better than the other in my 2004 Volvo S60R which is a 2.5 turbo with 300 hp and has 125,000 miles. I would say I drive more like a granny than a formula one driver. I average 27.1 mpg on my 45 mile dail round trip to work. My car uses very little oil even for a turbo (1/2 a quarter between the 7000 mile oil changes). Most of my driving is back roads hardly any stop and go traffic, summer time temps rarely get into the high 80's and winter time temps rarely get below 15 degrees. Pennzoil recommends Platinum 5w30. My owner's manual recommends Castrol synthetic blend 10w30 for the 2004 but when you check the 2005-2007 owner's manual they recommend 5w30 for the same engine no difference between the years. So between the Ultra and Platinum and 5w30 or 10w30 which one would best suit my car?