I had been a 3K mile OCI guy for no particular good reason. Then I found this site and have seen the light. I am currently at 3400 and am beginning to sweat bullets but I am determined to get to 5K. I am currently running QS Peak Performance 5W30 in a 98 Saturn SL2 with 122K on the clock. Not sure I'd see much benefit in switching to syn at this point in the car's life but my goal is to get to 200K. Still get 32-34mpg. Great site!