So my Subaru sounds like a diesel!

[aircraft engineer]

according to the MSDS description, it's a terpene and is also an intense degreaser. At the dosage of 2oz per quart it would take a bit more than 1/2 cup for a engine.

 

(citrus derivative - one of the common names is "Citrusafe")

 

I would have never thought of adding it to a motor, though.

 

It will modify the oil number a bit (it's "dilution") so your 5w-30 might wind up being 5w-28 (yeah, the first number doesn't change a whole lot even if diluted, what changes is the thickening effect at temperature)

 

google "citusafe" and you can see the "home" uses of the product.