Used Oil Analysis : 2010 3 door Yaris : 4,341 mis. on oil and 16,611 miles on engine

[Hershey]

PENNZOIL conventional 5w-30 ( SN/GF-5 ) , TOYOTA oil filter 90915-YZZF2 . Air filter is factory installed . Replaced with SHELL full synthetic 5w-30 ( SN/GF-5 ) and TOYO oil filter . Previous 2 O.C.s were SHELL conventional 5w-30 ( SM/GF-4 ) and TOYO oil filters . Plan to get U.O.A.s every 35,000 mis. or so to check for possible coolant , engine wear , and oil performance . We're thinking of getting another analysis for the '08 sedan that had head cylinder gasket replaced . Will likely post that in near future .