Originally Posted by tap4154
I go by the chart in the manual, which goes by the temperature that you're probably going to be camping in, so I put 30 weight in mine because I usually camp in moderate temperatures. I suspect the change to a multi weight is so you get better mileage with your generator?
Ours is a 2003 so may have different specs than newer 4000 models.
My manual plainly states, and I quote, "Single grade SAE 30 oil is preferable when ambient temperatures are consistently above freezing". The chart below that statement in the manual shows the recommended viscosities below.
30W is good for 32° and higher,
15W-40 is good between 10° and 100°F,
10W-30 and 10W-40 are good between 0° and 80°F,
5W-30 is good between -20° and 50°F.
I live in the south so 30W is the logical choice. Still, I have no doubt someone will come along and say I am wrong.