The Ford Barn - View Single Post

Purdy Swoft · 05-16-2018, 12:56 PM

When I've used STP in an engine I mix the STP with motor oil in a larger container with a paint stick before pouring it in my engine . STP oil treatment can mix with oil but I prefer mixing it before pouring it in my engine . Years ago I tried straight STP for gear oil . I didn't like the results Of STP for gear oil and went back to 600 w . I have also used 90-140 gear oil with good results . As for motor oil , it needs to be thin enough to flow by gravity to the mains in a cold engine . Another important consideration is that the oil needs enough viscosity to cushion the bearings . Ford recommended 20 weight for colder temperatures and 40 weight for summer use . I don't like to use any oil with less than 20 w for colder tempreatures for that reason .

05-16-2018, 12:56 PM	#18
Purdy Swoft Senior Member Join Date: May 2010 Location: Alabama Posts: 8,099	Re: Another question about oil viscosity When I've used STP in an engine I mix the STP with motor oil in a larger container with a paint stick before pouring it in my engine . STP oil treatment can mix with oil but I prefer mixing it before pouring it in my engine . Years ago I tried straight STP for gear oil . I didn't like the results Of STP for gear oil and went back to 600 w . I have also used 90-140 gear oil with good results . As for motor oil , it needs to be thin enough to flow by gravity to the mains in a cold engine . Another important consideration is that the oil needs enough viscosity to cushion the bearings . Ford recommended 20 weight for colder temperatures and 40 weight for summer use . I don't like to use any oil with less than 20 w for colder tempreatures for that reason .