5w30 in a Generator

[64bawagon]

We inherited a bunch of generators at work that had mostly Honda engines and had been neglected for years. Most had frequent use with no oil change done in 3-4 yrs. Unknown what they had in them but all were fine after a fuel filter and some fresh oil. As much as I and other stress about oil in small equipment I think we worry about it way more than the engines do.
Acknowledging that I run 10W30 syn in mine.

 

[Lubener]

I use 10w-30 in my generator. It's is a good weight for Ohio's summer and winter temperatures which I encounter.

 

[mpgo4th]

changed the 5w30 out at 8-9 hours. It wasn’t low but it was dark. Not black but definitely darker than it should have been. Filled it with the 30w and ran it until the carb ran dry.

 

[wag123]

Am I wrong 0W-30, 5W-30, 10W-30 and SAE30 weight all meet the same high temperature SAE spec for SAE 30?

So in reality it shouldn't matter?

The ones with better cold pumpability tests may have more VII so may not last as long?

What Am I missing - they should be interchangeable no?

The amount of VII in the oil can be problematic in an air cooled engine. For this reason you should avoid 0wX and 5wX grades.

 

[dlundblad]

The amount of VII in the oil can be problematic in an air cooled engine. For this reason you should avoid 0wX and 5wX grades.

I use 0w40 in all my OPE including a tired ~20 year old push mower. Zero issues.

 

[Cujet]

There is no downside to choosing a robust oil for hard working air cooled engines. There is risk of failure with inadequate viscosity. Some engines do not manage oil temps well and will fail if overheated.

An example of a situation where an air cooled engine can overheat it's oil is 24/7 generator use after a South Florida hurricane. Hot stagnant, humid air is less than ideal when running a 5000W generator to power a 4500W water heater for hours on end. The number of generator failures after a storm is epic. I use M1, 15W-50 in my air cooled generator here in Jupiter, FL.

 

[repairman54]

Oil choice should be temperature zone based. Southern heat needs higher top numbers for sure in summer usage. Northern choices are more low temperature based. I could not pull start a 5600w BS at zero with 5-30w synth. in it even though the chart said it was OK, needed to switch to 0-30w to get it to pull over fast enough to fire up in the cold. Highs rarely get over 85f in that area.
When you're lifting the gen set off the ground with the recoil and it still will not spin over fast enough to start your oil is slightly too heavy. In my middle zone in NW NJ the 5-30 works fine in an identical gen set. No real oil usage in summer runs and winter starts are fine.

 

[64bawagon]

My big gen is stored in the garage and my portable 4500 inverter gen is in the barn. Neither one gets anywhere near freezing so I have much less worry about oil weight.

 

[FordSVTGuy]

My big gen is stored in the garage and my portable 4500 inverter gen is in the barn. Neither one gets anywhere near freezing so I have much less worry about oil weight.

Yeah, that’s a great point. I keep my Firman generator in my garage where it doesn’t generally go below freezing. I tend to need the generator after summer storms, so I use VP 10w-30 full syn…

 

[Sequoiasoon]

Mine sits in my shed. Could be really cold in winter or really hot in summer. I just took out I think Rotella T6 5W-40 with some fuel dilution. I put M1 15W-50 after reading some other threads on line with the hot temperatures and generator failure like Cujet said. I'll have to see how the pull start does when it gets cold. I have used my car jump pack clipped to the battery cables (and wife/kids have also). That cranks well.