Where I live it's not easy to plug in my block heater. Starting my car last winter when it got down in the 20s wasn't easy, and the valves were properly adjusted. One of the things I'm thinking about doing is putting lighter weight oil in for the cold months. I currently have Rotella 15W40 (dino) in it. I don't want to use synthetic oil as the car already has a tendency to drip, I'm afraid it would be a fountain with synthetic oil. I've tried synthetic oils in the Rodeo and experienced both leaking and burning which I don't with dino oil.
So, I want to lower the first viscosity number (15), but there are no diesel-rated oils lower than 15 except synthetic.
I've thought of 2 things:
1. A good 10W40 gasser oil (Castrol GTX) with some expensive ZDDP additive (zddplus). This still wouldn't have much in the way of detergents or soot control, though.
2. A 50-50 blend of 15W40 Rotella and some 0W30 gasser oil. This would be a 7.5W35 mixture, and would still contain half the diesel agents (ZDDP, detergents, soot control). *Note: people elsewhere have told me that oil viscosities don't mix like this--blending a quart of 0W20 and a quart of 10W30 would not produce two quarts of 5W25, is this true?*
Which do you think would be better for the engine (which will probably only go 2,500 miles between this oil change and the next one in spring)?
So, I want to lower the first viscosity number (15), but there are no diesel-rated oils lower than 15 except synthetic.
I've thought of 2 things:
1. A good 10W40 gasser oil (Castrol GTX) with some expensive ZDDP additive (zddplus). This still wouldn't have much in the way of detergents or soot control, though.
2. A 50-50 blend of 15W40 Rotella and some 0W30 gasser oil. This would be a 7.5W35 mixture, and would still contain half the diesel agents (ZDDP, detergents, soot control). *Note: people elsewhere have told me that oil viscosities don't mix like this--blending a quart of 0W20 and a quart of 10W30 would not produce two quarts of 5W25, is this true?*
Which do you think would be better for the engine (which will probably only go 2,500 miles between this oil change and the next one in spring)?