Many generator manufacturers recommend a 5W for cold starts 32 below I don't see an issue with your choice. Modern Generacs use 5W20 year round they're living dangerously or what lol?
So what actually is the best small engine oil?
- Thread starter Jmoney7269
- Start date
SuperTech Blend 10w-40 in all my OPE. After Hurricane Matthew my 8500 KW generator ran 24/7 for two weeks straight while the house was being put back together. Had to keep the two freezers and a fridge running. The only time it didn't run was when I filled up with gas after a days work, around 9pm, and went to my daughters house where we were living. I'm guessing it ran out of gas around 7am.
The generator survived fine But not the food. Turns out we had to pitch all the food we were trying to save ($).
The generator survived fine But not the food. Turns out we had to pitch all the food we were trying to save ($).
I am in the strait 30 weight heavy duty oil camp. My VW Beetles have taught me that. Protects at start up and thins at heat to flow and protect.
Its all about your ambient operating temperatures. 0w bottom number in northern climates for easy winter starting, southern temps at least a 10w bottom number for hot weather.
For the small amount of oil needed use a full synth. oil and change it regularly.
My 30 yr. old Briggs are still churning away just fine with oil and air filter servicing. As well as my Tecumseh flat head snowblowers.
Stabilize your fuels for even less issues. I keep my gas cans stabilized year 'round, even with E0.
When its time to go I want it to go without problems.
For the small amount of oil needed use a full synth. oil and change it regularly.
My 30 yr. old Briggs are still churning away just fine with oil and air filter servicing. As well as my Tecumseh flat head snowblowers.
Stabilize your fuels for even less issues. I keep my gas cans stabilized year 'round, even with E0.
When its time to go I want it to go without problems.
That was my maintenance regimen back in NY. Old yard machine snowblower with a 5hp Tecumseh. Would Start 1st pull every single time cold hot and out of storage. electric start was nice at 3am though lol.
Proper lubrication occurs at an oil viscosity of around 10cSt.
Most engines run at around 100c usually + or - 10c and at 30wt oil is perfect.
I only run 20w-50 oil in engines doing things that drive the temperature well above 110c.
Such as my riding lawn mower, pressure washer and my fixed speed generators. Generators need 40wt oil the way I run them, but I'll put 20w-50 if I don't happen to have an S series oil in 40wt on hand. But a 30wt oil is fine during the winter as they run a lot cooler when it's below freezing, also pull starting gets much more difficult below freezing when there's 20w-50 in the crank case.
Run M1 15W50 FS for 4-stroke B&S mower and motorcycle. Only used late Spring through early Fall so temps are in the mild to hot range. All good after many years.
Past two winters I used Mobil1 EP 5W30 in the oil sump . I added two tables spoons of Militec1. Has purred like a kitten. Briggs and Stratton small motor. Not much oil in sump when servicing
Ding ding ding, we have a winner!
These engines are not very picky about oil or fuel, so whatever you have open is probably good to go.
Now, if I expected to run a genset for maybe days at a time after a severe weather event, then it might be worth splurging on M1 15W-50 or maybe a 20W-50 grade oil.
0W-40 here. If it’s good enough for Porsche with A40 approval it’s good enough for my lawn mower and other OPE including my generator. If it were extremely hot I’d use 15W-50.
The only small engine I have in my life is a broken predator generator and it got O’Reilly high mileage 10w-30 because it was given to me for free. I’d say free is the best price. And no the generator is not broken because of the oil.
I want my generator to turn on when it’s cold. Even though it has an oil filter heater, it sees 0w40.
- Joined
- Sep 22, 2025
- Messages
- 180
I'm too new around here. Who is Tony? And best oil is 100% based upon anecdotal's.
He used to own this BB. After Bob, before Wayne.
Or Mobil1 10w40, 0w30!!
Try Mobil1 0w30, it is awesome in cold/warm weather!!
The oil used for Top Fuel engines would be a poor performer in a small engine unless you planned to change it every hour of run time. Nitro SAE 70 is essentially just BS150 with some ZDDP and a tackifier.
I use HPL Small Engine Life 10W-40 in all of my small engines.
I use HPL Small Engine Life 10W-40 in all of my small engines.
Similar threads
