4 qts Amsoil SS 0-20, 1 qt Amsoil SAE30. Ran for 1 yr 3 months. Engine has 90,070 miles on it. 4,000 miles on oil. Engine is 94' OHV 4.0. Driving is short trips in winter, longer trips during warmer weather, lots of off road and dirt roads. Engine calls for 5-30. I did not change oil yet. I drained one qt out for sample and added one qt of Amsoil SS 10-30. Should I change oil or no?
Iron 17
Lead 5
Copper 3
Aluminum 3
Silicon 10
Sodium 99
Potassium 52 (flagged for possible coolant)?
Mg 600
Calcium 1234
Phos. 629
Zinc. 800
Moly. 148
Boron. 41
All others less than 1
Visc. 9.8
TBN. 3.5
Iron 17
Lead 5
Copper 3
Aluminum 3
Silicon 10
Sodium 99
Potassium 52 (flagged for possible coolant)?
Mg 600
Calcium 1234
Phos. 629
Zinc. 800
Moly. 148
Boron. 41
All others less than 1
Visc. 9.8
TBN. 3.5