Generator Oil in Hot Weather

[Wertles]

Synthetic oils are better in every situation. Period. They flow better on start up. They maintain their lubrication properties better at high temps. They maintain their lubricating properties over a longer period of time. The only time synthetic oil may be at a disadvantage is during break in of a diesel motor. The oil is so slick it just takes longer for the rings to seat however, this is really not an issue with today’s modern diesels. Don’t think that what was the standard 30 years ago applies to today’s engines. When was the last time you saw a 3000 mile oil change? Not in years. Engines are built with tighter tolerances, run cleaner, and today’s oils have additives to make them last longer.

Run a high quality synthetic 30w, 10W-40 or 15W-40 (diesel) oil, change it on time, exersize the generator often, and it will give you years of service without an oil related failure.

[gprapim]

Originally Posted by Wertles

Synthetic oils are better in every situation. Period. They flow better on start up. They maintain their lubrication properties better at high temps. They maintain their lubricating properties over a longer period of time. The only time synthetic oil may be at a disadvantage is during break in of a diesel motor. The oil is so slick it just takes longer for the rings to seat however, this is really not an issue with today’s modern diesels. Don’t think that what was the standard 30 years ago applies to today’s engines. When was the last time you saw a 3000 mile oil change? Not in years. Engines are built with tighter tolerances, run cleaner, and today’s oils have additives to make them last longer.

Run a high quality synthetic 30w, 10W-40 or 15W-40 (diesel) oil, change it on time, exersize the generator often, and it will give you years of service without an oil related failure.

X2 - This is right on with my thinking and experience using synthetic oil since 1979 in everything I have owned then and since !!

[curver900]

Originally Posted by cabinetmaker

Not all motorcycle oils are made for wet clutch bikes. Harley oils come to mind. Motorcycle oils are developed for severe service and I would never run them in a car or truck but in a air cooled generator would be fine. I probably shouldn’t have mentioned this because I have raced bikes for years and built high powered motorcycle engines and believe me I know motorcycle oils. They are some of the best oils out there. I guess I should have left that out of the conversation to limit confusion. That wasn’t what this was about.

Here are the facts. Onan does not recommend synthetic oil! Onan does recommend diesel oils for the air cooled gasoline engine generators. 15w40 oils are diesel rated oils. Just trying to help here!

Interesting all the Harley's I've owned had wet clutches sportster, softail my Yamaha Griz has a wet clutch, my aprilia and one Ducati has a wet clutch, my Ducati MH900e has a dry clutch... even my suzuki 4 wheeler has a wet clutch... They also make a synthetic oil that is compatible with wet clutches... Amzoil, royal purple , Mobil1, etc... My point is they have different specs than car oil they have additives that keep the wet clutches from being to slippery... the additives are different... not saying it is good or bad just different and that they need to meet the specification of the motor... or be better than that... But motorcycle oils are no better or worse than car oil... but motorcycle oil doesn't meet the specifications of any new car oil requirements...

at the end of the day just make sure your oil meets or exceeds the specs for the type of motor you are putting it in...

[cabinetmaker]

Ok...don’t shoot the messenger here but I just talked to Onan corporate technical and they said this:

Synthetic is not recommended because of several reasons. One is you can’t extend the oil change requirements for any reason so synthetic is not necessary. He also said that the Onan generator engines are old school motors and don’t require or even benefit from synthetic. Synthetic can increase oil consumption. Lastly he noted that all the oils that Onan puts their name on and sell /recommends to all dealers and service centers is good base stock normal motor oils with good additive packages specially formulated for Onan generators. They don’t sell or recommend synthetic oils.

He did say that you can use regular good quality oil if necessary but just make sure it has the correct rating. Said the oil is very important to keep changed regularly. Hot summer use is considered extreme service so oil change intervals need to be strictly adhered to or even increased. Oil level should be checked every day of use.

He went on to say that many modern synthetic oils are great for car engines that have tight tolerance and trying to achieve the best emissions and miles per gallon. They aren’t necessarily best for Onan old school carbureted engines.

He said you can use synthetic just don't extend drain intervals and keep a sharp eye on consumption and be sure it has the correct API oil rating.

[NC Roamer]

Originally Posted by Old skipper

Why would you be concerned? Monthly maintenance on the generator is to run it. New generators first oil change should bevatb50 hours. Then 150 hours or 12 months if hours are not achieved. Oil changes are good insurance.

My Onan manual said to do an oil change after the first 20 hours and then every 150 after that. I use their OnaMax multi-weight oil.

[JesseS]

I have used 30W AMSOIL Premium synthetic oil in my air cooled engines and Genset's for years without issue. And I use their 10W-40W in my M/C's. I have a genny at my cabin that has over 800 hours on it using Amsoil synthetic.

[Formula1]

Originally Posted by jnunes22

Onan rep says: I've never seen that in our manuals. You can use synthetic but you wouldn't get all the benefits from it as if it was in the main engine

When I get a chance I will try to copy and paste and send them where it says that in their manual.

I needed to do an oil change and looked in the manual. It says synthetic is not recommended for diesel generators but does not say the same for gasoline generators. By default I"m pretty sure it means synthetic is fine for the gasoline generators. So I'm sticking with synthetic for my gasoline generator. Been using synthetics since the 80s for both road and racing applications and it's saved several engines when they overheated due to cooling issues and the engines came out without any damage I could notice upon tear down.

[gprapim]

Originally Posted by Formula1

I needed to do an oil change and looked in the manual. It says synthetic is not recommended for diesel generators but does not say the same for gasoline generators. By default I"m pretty sure it means synthetic is fine for the gasoline generators. So I'm sticking with synthetic for my gasoline generator. Been using synthetics since the 80s for both road and racing applications and it's saved several engines when they overheated due to cooling issues and the engines came out without any damage I could notice upon tear down.

X2 - I totally agree and have used synthetics in everything I have owned since 1979, as well as M/Cs and off road racers. Just did my V-10 and gas Onan yesterday with the same.