5w40 will be the same viscosity at operating temperature as 15w40. It is just thinner at startup.So dudes, you convinced me to switch over to 5w40 for this oil change coming up. So educate this here dummy, what's the downside to 5w40 rotella in summertime, none right? And any issue mixing it with 15w40 I have left over, come next oil change in spring/summer?
Also right quick, are you all changing your coolant every year regardless of hrs put on it? I put in the hd extended life stuff last fall.
So if I mix those 2 together, do I get 10w40?5w40 will be the same viscosity at operating temperature as 15w40. It is just thinner at startup.
Coolant is typically good for 6 to 10 years. Ten years on virtually all vehicles now. Next year is the 10th on my diesel generator. Time for coolant and all filter and oil change to 0w30 M1 ESP like is in the JD.