Oil Viscosity

[walela1]

A new oil thread perhaps, but I need help here. Some may have read my recent posts entitled Vibrations and Cops, where I tried to relate a perceived misfire situation.

I added two quarts of 5w30 Royal Purple because I noticed the oil level down, I am already running RP 5w20 so those two quarts brought the dipstick level up to the proper level. Does mixing oil viscosity cause situations like I describe in my two previous posts, or contribute to causing the problem?

[finster101]

Mixing viscosity will cause no problems. The question I would ask is why were you two quarts low?

[Black_Noise]

The question I would ask is why were you two quarts low?

What he said

[RF Overlord]

walela, mixing different viscosities of the same brand is not a problem. In your case you'll end up with something like a 5W-23... :rolleyes:

Mixing oils from different blenders is not ideal, as it's possible to end up with an oil that's not as good as either one is separately (due to additive clash), but there's no real harm in doing so and in no case will it cause your motor to vibrate or run poorly etc.