Just thought I'd pass on some info on an 05 Toyota Prius from fleet service. This vehicle was used in the city of Los Angles for document pickup and delivery, and lab samples too, with the same four drivers for 11 months and 2 weeks with one driver doing a little over 50 percent of the mileage. The mileage at the end of this period was 87,551 miles. The car averaged 52 mpg of mixed driving and used Motorcraft 5w-20 oil changed at 5k intervals, which averaged about once every 3 weeks. The car was on it's third set of tires and lived a hard life. No used oil analysis, but there was no unscheduled maintenance, and the brakes had a front pad change and still had some life. This may have been because of the re-gen system. The coolant and brake fluid were not changed. It looks like 5w-20 oil did a good job. I drove the car the week it was sold off, and it ran like brand new.