I wanted to run mystik jt-8 10-30 in my rebuilt 390 but i can not find it anywhere.What other oils are SL and CI-4 rated? I found some mystik 15-40 but i think that is a little thick. It is really cold up here. I can get citgo in a 10-30. Is that the same as myistik? Is 15-40 to thick?

 

The Citgard 500 or 600 is similar to the mystik JT8. Citgo Superguard is not diesel rated. The diesel rating is what you are looking for. If you have a fleet farm nearby, I think their house brand is very similar or the same as Mystik. Tractor supply also has mystik sometimes. If you don't have a fleet farm nearby, find a diesel rated 10w30 like Shell Rotella, Chevron Delo, or Mobil Delvac that has a steady supply at the right price, no matter the brand. It is easier that way. Any diesel CI-4 rated oil will work great in your FE.

 

Is the 15-40 a lot thicker than gasser oil in 10-40?

 

If the temperature is above 30 degrees you won't notice much difference between 15w40 and 10w40, but below 20 - 30 degrees the 15w40 starts to behave more like a straight 30 wt. 10w40 will be ok down to 0 degrees.