My car was using 5W-40 and I felt a bit rough when shift to engine driving. After I had changed it to 0W-20, the petrol engine is running as smooth as the running hybrid battery. This lubrication oil 0W-20 is make for hybrid engine where there is a lot of start and stop. I feel very happy and enjoy driving my car.

 

0W20 is the correct oil to use. See attached

 

I wonder why you used 5w-40 in the first place? It is a regional thing? Are you in the correct forum? (rx400h?)

 

5w30 is for RX400h... And I wouldn't recommend shifting into 0wXX. I had "check engine" light when dealer used 0wXX in my Toyota instead of 5w30 (as written on the engine), and the error has gone when I returned to 5w30.

 

0w20 is the oem recommended oil to use (right in the manual) - these engines last very long as toyota figured out how to get them to run optimally at very cool temperatures - OP, why would you use 5w40 oil? that is for engines like in the 911, where the engines run MUCH hotter.

 

Folks, OP looks like a marketing post. There is no such thing as hybrid oil. Vehicle per Op was already run on wrong oil. It is normal for hybrid vehicle to have a little shudder, when ICE turns on or off.
Forgive me, if I'm wrong, but it looks like a bot post paid for by oil company.