Pennzoil specifically warns against using different oil weights -- the number following the dash -- in your car's engine.

One Tacoma owner ditched Toyota’s recommended oil for something thicker, and the results have sparked a heated debate. Is ...

you should be using a full synthetic or synthetic blend 5W-20 oil. A 6.2-liter HEMI engine requires 0W-20 oil, which is a bit lighter when the engine is cold. Drivers of vehicles with 6.4-liter ...