Just had 8,000 mile service on my 07 X500. Went with Ams oil synthetic and added Tuf Oil additive. Put on Shad SH45 box, and new Michilin gold standard touring tires, (much better ride than stock kenda's)! I average 55-57 miles per gallon at 65 miles per hour, (no joke, I am not kidding)! Bike is stock, original air filter, new NGK plug, oil and additive and thats it, nothing else has been done. I get this mileage solo or two up touring. I have no idea if the original owner changed carb jetting or not? But I could not be more happy. No Dr pullies, malossies, or after market exhaust for me. I ain't changing nothing! Tuf oil is in the Guennis (spelled wrong I know) book of word records as the most slippery substance known to man, it really works. I get 28-32 MPG at 60 MPH in my BIG Lincoln Contenental. Warning, Tuf oil can not be used where there is a wet clutch! Too slippery! Not for auto tran's in cars, or bikes that share engine oil with the tran's. X500 has dry clutch, so is ok. Also I put on 2009 seat, much better than high peaked 07 seat. I rode it 1,300 miles the first week I had it. I am absolutely in love with this scoot. Rode about 300 miles yesterday. Got home, took a shower, and went on a sales appointment and felt as if I had never been on the bike that day. Last bike beat me to death. Now planning long week ends and camping trips.