At the first of July I was transferred to one of our other plants, that is 95 miles away, and given a company car to drive. The car is a 2007 Altima. When I first started driving it, it had a fresh change of Havoline 5W30 in it and was averaging around 26.3 miles per gallon. At the end of that OCI it was serviced by a different service center. I noticed that the fuel mileage jumped to around 27 mpg. I tried different brands of fuel but, the mpg stayed at 27. Toward the end of that OCI (5500 miles) the mpg crept up to around 27.5. I had the car serviced earlier this week and the mpg is still at 27.5. I called the service center to find out what brand of oil that they used in our company cars and the manager told me that all our cars get Kendall GT-1 synthetic blend. I plan to try Kendall in my wife's car at the next change and see if I get similar results. Anyone else have any experience with Kendall and fuel mileage increase?