Oil viscosity

[Ron & Dee]

What oil viscosity should I use?

My oil fill cap says 5w30, I see some on this Forum use 10w30 and other viscosities, so what are the determining factors in choosing the right viscosity?

Thanks,

Ron

[RVDude]

Temperature is the primary factor. Your engine manual should have a chart and it is your primary guide for viscosity choice. Generally, the manual will give 2 or 3 options, often the dividing line is if you intend to operate primarily at 32 and below or 32 and above.

[JC2]

When they were still reasonable in price, the WH center we used always put in 10w-30 Dino oil in ours. I've since had that continued at other oil change places as I've never felt comfortable using 5w-30 in a big engine. If we lived/traveled to a place where the temp(s) were consistently below 0F, I would reconsider or go to Mobil 1 synthetic.
We have always changed our oil at 1yr or 5000 miles.

[hamguy]

I drive our rig 10-12K/year. It is now at almost 80K miles I have used 5-30 and 10-30, dino and synthetic. I now stick with 10-30 dino. I change at 3000-5000 miles depending on memory, miles and opportunity. Typically add a qt. at 3000-4000. I do NOT go where temps are under 30 or over 90. (that's why we got the RV )

Dean