Question: what is the difference between 5w 20 oil and 5w 30 oil?
Answer: The main difference between 5W-30 and 5W-20 motor oil is that the latter gives a slight bump in fuel efficiency. When used in a vehicle's engine, 5W-20 oil creates less friction due to its thinner viscosity (or thickness), meaning it drags less across engine parts like the crankshaft, valvetrain, and pistons.