At least once a year, as the oil gets contaminated with fuel residues etc when the engine is running, and also by getting hot, then cold over and over, and all that contamination forms an acid in the oil, that is not good for the internals in the long runWhat is the suggested oil change interval if you drive about 1-2k miles a year?
From what I have read over the years oil additives are a bad idea. Additive clash can destroy an engine or at the very least greatly accelerate wear.Being a cheap F, I probably would not buy it. Reason being I can buy ZDDP plus http://zddplus.com/ and "regular" 20W-50 oil (Walmart house brand, I know it is made by one of the majors) and be pretty much (guessing) in the same space as a boutique oil such as you are suggesting. How much cheaper would it need to be you ask? In 10 bottle quantity, ZDDP plus is $8 (shipping included), WM oil is, jeez, I forget, about $12 for a 5 quart jug?, so $20 and I'm good. If you could compete with that, or close, might be a possible for me but refer to the first sentence above... :buck: