2005 chevy trailblazer 4.2 260,000 miles,bought as a program car in 06 with about 12,000 miles on it, ran mobil 1 5-30 for about 100,000 miles then switched to napa 5-30 synthetic napa gold filter, all I have done to it is alternater, clutch fan and water pump,and front diff seals,still take a...