the car is an 04 S60 with a 5 speed manual and a mere 53400 miles on it since new (first owner).

He has several reciepts that date back to new when the dealer did full syn oil changes since new...then the owner got cheap and got them to use only dino oil.

I want to switch back to syn, and run extended intervals (since I inow that a clean little N.A. Volvo engine can easily run a good distance on dino, before requiring an oil change.)

Since it's not a turbo model, which name brand and interval do you suggest? I plan on sticking with the 10W30 that my dad use to use on his old 73-81 (145-245) Volvo Wagons (totally different animal I know, I just think it's neat that they still use the same grade, so many years later!)

FYI -I used to run Full syn Mobil1 in my 97 Escort for 20,000kms (or 1 year) intervals and had NO problems with oil consumption or leaks! Heck I'm sure I could easily run it for 30,000kms

thanks in advance!