What Weight Oil Do You Run In Your Generators ?

Is that universally true?

Better in what way, sometimes the base stock gets better, sometimes it seems to get worse. Add pack?

I get that it probably has a higher HTHS number - but how much higher?

IF you are going to address a hot running condition by upping the W number - why not narrow the spread further by going to 20w-40?
Not sure Mobil would agree Delvac Super is better than Delvac 1 ESP … but both can do gens.
I find it easier on the pull start gens with 5W40 …
Not sure Mobil would agree Delvac Super is better than Delvac 1 ESP … but both can do gens.
I find it easier on the pull start gens with 5W40 …

My questions were based on threads where this difference in base was pointed out by comparing spec sheets hence is it universally true?

Makes total sense the 5W is going to be easier to pull...
I run T-6 or Mobil 1 5w-40 year round. I use my generator 100-150hrs in the summer and maybe 200hrs in the winter, change the oil every 100hrs or so.
Used to run 10W30 Valvoline Racing Synthetic with a tiny bit of LiquiMoly MoS2. That lasted ten years, worked GREAT,
I finally did a drain and fill this Summer with Mobil 1 5W40 Porsche A40 stuff. We will see how that goes.
OTC ILSAC GF-5 synthetic PCMO does NOT cut it in a Generac GP 5500
Chevron Supreme 5w-30. Some may shudder at that, but then again they do not run a tuned EU2200i. It should be obligatory on any small motor these days as they run lean which equates to HOT. Not so with this little guy. Search on the forums to do the pilot at least (it effects the entire range of the three stage carb). But such is life and the degree with which they tinker.
Yamalube 20W-50 in my Yamaha 2400 gen right now, but not my choice. I took it to the dealer a couple of years ago for tune up and oil change after 5 years of non-use.

When I picked it up I asked them what kind of oil they put it in it and they said 20W-50 is all they carry and is what they use in everything. Seems kind of extreme to me.

It’s about time to change again and I have no idea what I’ll end up using. I think I was using 10W-30 before.
It would be interesting to know what the operating oil temperatures are on some of these larger air cooled gen sets, when operating at or near a maximum load? I know the crankcase on both of my Westinghouse 9,500 watt units gets too hot to touch, in just under 4 minutes of operation. 20W-50 does not seem an unreasonable choice at all.
Usually Rotella T6 5w40 or a Euro oil like Valvoline 5w40. Easy starts in all weather and less oil burn off while running for extended periods of time.
Kohler 10w-30 Synthetic Blend . Same oil I use in my Bad Boy ZTR and Toro pushmower . Keep it simple .
I never understood why individuals start a motor over for a few minutes when lubrication (which touches seals and the only reason to start) can be had with a 3-4 pulls of the starter cord? If you’re starting up to make sure it runs, that’s one thing….but, usually well taken care of machinery doesn’t konk out after few months. Only adding moisture to the motor too/bottom in such small sump quantities “ain’t” a good thing.
I changed the oil in my Wen 56380. I dumped out Super Tech 10w30 FS HM and replaced it with the same. Oil change had about 80 hours on it and ran for the last 65+ hours straight while powering my camper. I burned about 12 gallons of gas powering 2 fridges, the furnace fan, the microwave and water heater. This thing is pretty darn efficient!

I debated on using Mobil Delvac 15w40 but had an open bottle of Super Tech and the drain pan looked good today. The magnetic dipstick had just a small amount of debris on it.

Just my $0.02