I thought I would experiment with M1 and Castrol 5W30 EP oils which claim up to 20 K miles OCI (Castrol EDGE EP) .
Since most of my Kia Sedona driving is closer to severe service schedule (3,750 miles OCI) , I like many others just throw out : "I'll just cut the max OCI stated by M1 / Castrol EP in half and run a 10K OCI " . After all , many auto technical sites state too many people run too short of an OCI with modern oils and say even vanilla M1 is good to 10K mile OCI's ... *Does that really make sense though ? If the OM states severe service is 3,750 miles and normal service is 7,500 miles many of us don't conform to either with our driving styles , so we are apt to just "meet in the middle" and run a 5K miles OCI . So why just because you switched to a M1 / Castrol EP oil do we just blindly bump up to the 10K OCI or more (especially if the vehicle has a timing chain) ? Conversely , I believe a M1 / Castrol EP oil can give up to 12 months protection on a low mileage driven vehicle and for the most part defend against acids and sludge but pushing much beyond the normal serve schedule of 7,500 miles OCI without an UOA may be wiser than just jumping on the 10K+ OCI band wagon of an M1 / Castrol EP oil unless you are 90% interstate miles... I'll put a stake in the sand and now feel comfortable saying 12 months / 8K mile OCI and then get a UOA to test with M1 / Castrol EP oils...Your thoughts ?
Since most of my Kia Sedona driving is closer to severe service schedule (3,750 miles OCI) , I like many others just throw out : "I'll just cut the max OCI stated by M1 / Castrol EP in half and run a 10K OCI " . After all , many auto technical sites state too many people run too short of an OCI with modern oils and say even vanilla M1 is good to 10K mile OCI's ... *Does that really make sense though ? If the OM states severe service is 3,750 miles and normal service is 7,500 miles many of us don't conform to either with our driving styles , so we are apt to just "meet in the middle" and run a 5K miles OCI . So why just because you switched to a M1 / Castrol EP oil do we just blindly bump up to the 10K OCI or more (especially if the vehicle has a timing chain) ? Conversely , I believe a M1 / Castrol EP oil can give up to 12 months protection on a low mileage driven vehicle and for the most part defend against acids and sludge but pushing much beyond the normal serve schedule of 7,500 miles OCI without an UOA may be wiser than just jumping on the 10K+ OCI band wagon of an M1 / Castrol EP oil unless you are 90% interstate miles... I'll put a stake in the sand and now feel comfortable saying 12 months / 8K mile OCI and then get a UOA to test with M1 / Castrol EP oils...Your thoughts ?