Ok, I have read the post on here concerning synthetic oil and just want to get some feedback on what I want to do. Here is my plan and need to get your guys/girls thoughts. I have a 2000 R with 68,### miles and use to be the daily driver. I bought a Toyota Truck as a daily driver (Oct 04, I love the truck and enjoy the R even more when I drive it now) and now the R sits in the garage and gets driven once or twice a week to pick up pizza or to hit the town on Friday or Saturday nights. I use to change the oil at the dealership every 2,500miles (typically every 2-3 months) with Castrol 10-30w and OEM oil filter. Since the R sits in the garage and don’t drive it very much I was thinking of changing over to Castrol Synthetic 10-30w and perform oil changes every 5-6 months (if I don’t hit 2,500 miles which I doubt I will) at the dealer. Also since I drive the car hard, when I do drive it, I figure the synthetic will do a better job at protecting my engine at high temps and during start ups. I'm in Sac Cali so it rarely gets below 25degreesF and gets into the 100's in the summer time if that maters. Can I still use the OEM filter with the Castrol Synthetic? Do I need to do anything to my engine before I switch over to Synthetic, if I do any estimates on how much it will cost me? Any comments, suggestions opinions are welcome.