Can I run 5W/30 oil in my 2006 Dodge Grand Caravan? The engine is a 3.8 with 52K. The manual says to use 5W/20. 5W/20 just seems way to thin. Its like pouring water in the engine. I was talked into trying Northland 5W/20 synthetic oil for my van. It looks green coming out of the bottle. After changing oil, started the van up and I could hear slight rod knock.
Not - A - Good! So, I went back to 5W/20 Havoline which I had been using.
I've always run 5W/30 in my Dodge vans. This is the first van that it says to use 5W/20.

At 200 degrees you would not be able to distinguish the difference in thickness between the 2 different weight oils. Run what the manufacturer recommends.

The viscosity index (10W20) is moe and EPA uissue (better fuel economy) than anything else, CASTROL is currently marketing a 0W30. 10W20 will not hurt your engine.

Manufacturers switched to 5W-20 to improve their CAFE numbers. Some engines are designed to use this motor oil, but our engine designs haven't really changed since they said to use 5W-30 in them. The same thing happened to my old 2001 Taurus. The year before, they said 5W-30, and in 2001 said 5W-20. My friend was a master Ford mechanic and he told me this. So, I use 5W-30 in my van.

Just use what is recommended, you will not see any difference between them. This isn't the 60s when you sculpted main bearings out of babbit.