Just got a new engine and I have synthetic 10 - 40 and shell 20 - 50, I usually use the 20-50 all the time and was planning to switch to the 10-40 but Im not sure if I should use synthetic when running it in (or even at all), Im super nervous about wrecking another engine so Im here for advice, what oil should I use when running it in, and afterwards?
Thanks in advance.
Thanks in advance.