XLeatherNeck

I ended up putting 5w-30 in this time, but will switch back to 5w-20 during the next service. The only time the viscosity is different is when the engine is cold, and even then it's minimal.

olym4gery

No.

5W is the winter viscosity. 5W-20 and 5W-30, have the same cold viscosity.

20 is the nominal vicosity of the spec'ed oil. 30 is the nominal viscosity of the oil you put in.

Heavier oil will mean less MPG and power. It may not be as easy to pump as the spec'ed oil.

XLeatherNeck

You are correct. They both have a winter viscosity of 5, but the the 5w-30 doesnt thin out as much when the engine is hot. Thanks for correcting my error.