So I purchased a Genmax GM10500iETC generator because it's a tri fuel that I'll be able to plug directly into my natural gas line. Like **** near every generator it's Chinese and the the user manual isn't very specific. It says to use 10w30 oil. Doesn't tell me if it's conventional, synthetic, etc. It does say to change every 50hrs. Seems a little quick if you ask me but for only 1.25qrts no biggie. What oil should i put in this thing? I was thinking something with the BMW LL01 spec since it's gas and that spec is really good about corrosion. But I don't know if it takes a fully synthetic or not. Thoughts?
Generator oil?
- Thread starter FlyingTexan
- Start date
Any SAE rated automotive oil will work safely, but a DEXOS or other top rated synthetic oil will be better. The BMW spec oil you mention will be excellent.
50hrs is not very long IMO. I run my Wen 56380i ~100hrs on about 20ozs of oil. Unit has 777hrs on it and is going strong. I primarily use it to power my camper when at racing events. I have used a variety of automotive synthetic oils from 5w30, 10w30, 5w40 HDEO and now 15w40 Super Tech Syn HDEO. In your application I would pick up a gallon of 10w30 HDEO in your favorite flavor.
Just my $0.02
Just my $0.02
In your climate (Texas) 10w30 with a HTHS of 3.5 or better, such as diesel oil.
10w40 or 15w40 would even provide more film thickness.
10w40 or 15w40 would even provide more film thickness.
I use any diesel rated10w30 conventional in mine no consumption and change as per the manual
HPL CK-4 5w40 Cold Climate. Will cover any possible situation your generator encounters. And at only 2 quarts or so worth, it’s still so cheap it’s worth every penny! 
I use this in my Firman dual fuel generator. Started using it with first oil change…
I like conventional oil for my generator, as I have read here conventional oil holds contaminants in suspension better and It has no oil filter. I am running SAE30 at this point but plan to switch to 15W40 once I am out of SAE30.
Many Honda generators recommend 100 hour OCI. I personally think this is too long given there is no oil filter.
My generator really never gets used. Its waiting for the next hurricane. I fire it up every few months and let it run for 20 minutes just to be sure.
Many Honda generators recommend 100 hour OCI. I personally think this is too long given there is no oil filter.
My generator really never gets used. Its waiting for the next hurricane. I fire it up every few months and let it run for 20 minutes just to be sure.
.
In Texas forget about any 30 weight oil in an air cooled engine. 40 or 50 is what any air cooled engine in Texas needs. If it were me I would be running Mobil 15W - 50. It's expensive and sometimes hard to find.
In Texas Mobil 20W - 50 V-Twin motorcycle oil would also be a great oil to use in warm weather. It's also usually easier to find. But in cold, a lower first number will be easier to start.
For a lower price oil Rotella 40 weights would also work.
If it is going to start in winter the first number should be 15 or lower. The lower the first number, the better. Also, for very cold a 5 or 0 is preferred.
As the spread between the first number and second number increases the oil becomes harder to design and more expensive to make, and more prone to viscosity breakdown. Hence if you don't need a 5 or 0 for the first number a higher first number is a better choice, since it will hold up longer and better, because of less spread.
Forget about any 30 weights. They are just too thin for an air-cooled engine in Texas heat. Air cooled engines that use 30 weight oil in hot conditions are often air cooled engines that do not last long.
Also, be aware that, that engine is going to be throwing off huge amounts of hot air, so position it away from anything that would allow that hot air to stay around and be drawn back into it. It needs to be where it can get plenty of air that has not just left it.
Remember, when it first starts the oil is not up to operating temperature, so it's going to flow like the first number then. So a 15W for the first number will flow like a 15 then. So don't worry if the engine specks a 30 for the second number. A 15 will still flow well.
But in hot weather and after running long enough to get up to a stable fully hot oil in very hot weather in an air cooled engine that oil will thin out a lot. Usually the extra hot temperatures oils reach in such conditions causes them to thin out soooooo much that if it started as a 30 it becomes too thin to protect the engine resulting in destruction of the engine. So in those conditions start with something thicker like a 40 or 50 so when it thins from heat, it's still thick enough to protect.
In Texas Mobil 20W - 50 V-Twin motorcycle oil would also be a great oil to use in warm weather. It's also usually easier to find. But in cold, a lower first number will be easier to start.
For a lower price oil Rotella 40 weights would also work.
If it is going to start in winter the first number should be 15 or lower. The lower the first number, the better. Also, for very cold a 5 or 0 is preferred.
As the spread between the first number and second number increases the oil becomes harder to design and more expensive to make, and more prone to viscosity breakdown. Hence if you don't need a 5 or 0 for the first number a higher first number is a better choice, since it will hold up longer and better, because of less spread.
Forget about any 30 weights. They are just too thin for an air-cooled engine in Texas heat. Air cooled engines that use 30 weight oil in hot conditions are often air cooled engines that do not last long.
Also, be aware that, that engine is going to be throwing off huge amounts of hot air, so position it away from anything that would allow that hot air to stay around and be drawn back into it. It needs to be where it can get plenty of air that has not just left it.
Remember, when it first starts the oil is not up to operating temperature, so it's going to flow like the first number then. So a 15W for the first number will flow like a 15 then. So don't worry if the engine specks a 30 for the second number. A 15 will still flow well.
But in hot weather and after running long enough to get up to a stable fully hot oil in very hot weather in an air cooled engine that oil will thin out a lot. Usually the extra hot temperatures oils reach in such conditions causes them to thin out soooooo much that if it started as a 30 it becomes too thin to protect the engine resulting in destruction of the engine. So in those conditions start with something thicker like a 40 or 50 so when it thins from heat, it's still thick enough to protect.
Last edited:
I run 5w-40 Rotella T6 in both of my generators because they are the only two pieces of equipment I have that might be called upon to run at ambient temperatures anywhere between zero and 100 degrees F. Experience has taught me that generators tend to be run in the extremes. I've never relied upon one on a beautiful sunny 68 degree day. I have relied upon them after heavy snowfalls or summer thunderstorms. Were it not for the cold side of this equation I would just run a 15w40 HDEO and call it a day. I suspect that a great many of us here on this forum don't realize that it gets cold in Texas winters.
In Texas, unless you are up north in the panhandle. Forget about needing a 5w oil.
Generators work hard and the oil gets really hot, definitely hot enough to need an oil that ends in 40 or 50.
Down in south Texas a 15w40 is fine.
Generators work hard and the oil gets really hot, definitely hot enough to need an oil that ends in 40 or 50.
Down in south Texas a 15w40 is fine.
I run dino HDEO 15w40 in my Predator 3500 & 5500 generator. I would also like to get the gas kit for the 5500 as I already have the transfer switch and house plug set up for backup power. I also had the gas company install a line in on the gas meter, so I am able to use it whenever I get the gas kit for genny.
Does fuel type affect oil change interval? If I'm running it off natural gas wouldn't it burn much cleaner and not have deposits?
was curious about this, who I needed to call to have an outlet installed. It's not a plumber it's the gas company?
