clutch shouldn't be sliiping so early with moderate driving, however I have had the valve adjustemnt done to mine before and noticed a gain in mileage....this was at 45k or something. I'm now at 60k and have to go in for my 60k maintenance which will again involve valve adjustment. I've asked about the fuel system cleaners at a local garage and they informed me that theres a big difference between the $2.50 walmart STP sutff and what they use.....I don't really trust the guy so I didn't get it done. If you do then keep me posted if you noticed any change.