Pickup & Passenger Vehicle Diesel Engine Oil FAQs

I've looked online and can't seem to find what the zinc levels are in the Shell Rotella T6 5W-40 Full Synthetic Engine Oil; any info will be appreciated.

How much of engine oil is made up of additives and how do they help an engine?

My owner's manual says that in temperatures above 0° F to use 10W-30 oil, but I do not see that Shell Rotella offers a full synthetic in that grade. I only see 5W-40 oil. Could I use the 5W-40 in hotter temperatures?

I want to use Shell Rotella engine oil in my lawn mower, what do you recommend?

Are lower viscosity oils really better for my engine?

Can Shell Rotella oils help to reduce the amount of ash in a diesel particulate filter (DPF)?

I was told that there was research and testing done that Shell Rotella T6 was proven to be the best oil for a motorcycle wet clutch system. Is there any truth to this?

With winter coming, what should drivers and fleets be aware of when checking their coolant for cold weather driving?

How should diesel exhaust fluid (DEF) be handled to avoid reducing its shelf life in a shop or by drivers?