Originally Posted By: webfors
What grade of gas was used for the OCI?
Mainly 93 octane with some 50% mixtures of 89 octane and straight 89 octane as this was summertime high speed driving. The owners manual suggested 91 octane for summer temps. After this oil change we went back to using 87 octane for our local driving now with the Motorcraft 5W-30. I'll use this for this OCI of 5,000 miles. I'll change the Motorcraft oil at 5,000 miles and note what the iOLM says at that time. Unfortunately 93 octane is about $0.50 gallon more than 87octane where I live. In everyday driving I'm not sure it's justifiable for the extra expense of premium as it does run just fine on 87 octane. The uoa with the 5,000 mile OCI of Motorcraft 5W-30 will let me know how much fuel dilutes the oil under regular driving conditions and if possibly 87 octane is a factor.
Whimsey
What grade of gas was used for the OCI?
Mainly 93 octane with some 50% mixtures of 89 octane and straight 89 octane as this was summertime high speed driving. The owners manual suggested 91 octane for summer temps. After this oil change we went back to using 87 octane for our local driving now with the Motorcraft 5W-30. I'll use this for this OCI of 5,000 miles. I'll change the Motorcraft oil at 5,000 miles and note what the iOLM says at that time. Unfortunately 93 octane is about $0.50 gallon more than 87octane where I live. In everyday driving I'm not sure it's justifiable for the extra expense of premium as it does run just fine on 87 octane. The uoa with the 5,000 mile OCI of Motorcraft 5W-30 will let me know how much fuel dilutes the oil under regular driving conditions and if possibly 87 octane is a factor.
Whimsey
