I have a 98 F150 w/ the 5.4l. It was purchased new and switched to M15W30 at 1000 miles. I have always run the 820S filters. Oil changes have always been around 5000 miles, but over the last 20k around 10k. The truck has always burned about 1qt over 5000 miles. It currently has 75K on it.
After reading through this board, I changed the oil and put in 10W30 M1. I bought a 5qt jug from Walmart and added 1qt of M15W30, which I had leftover.
I want to verify that the mixture of the two weights will be OK.
Does anyone think the truck will burn less oil with the heavier weight? I live in TX, so this summer will show 100+ degree days.
How about running 10K changes? The oil was very "thin" coming out, but it was also very hot after a 25 mile run... I will test the oil after the next change, but that will be 4 months or so from now...