Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

I have a 30kw water cooled $#%*mins onan standby generator.The manual recommends 10w30'or 5w30.the company that installed it said they use 15w40.I asked them why and he said that the engine has an engine block heater and 10w30 was too thin for year round use.My question is ....would 15w40 be too heavy of an oil for use in the winter?Or is it ok since the engine has a block heater?

If the manual recommends 10-30 than that is what I would use.  If you want to be safe in colder weather than 5-30.  If you live where it never gets very cold but does get very hot than 15-40 would be a better choice.  The question is Winter is subjective to where you live.   Hawaii not too cold,  Noam Very cold.

Verify in your manual that the generator actually has a block warmer /heater. 

A block heater would only be used in REALLY COLD weather!! Hence making the engine easier to start... so if u were in warm climate then u wouldn't use block heater... in my opinion using 15w40 (w/block heater) in a colder climate doesn't make sense. and if they were using it in a warmer climate u wouldn't need the block heater!!!.. so either way u cut it make sense to stick with 10w30 for all seasons or if used in really cold weather use 5w30.... so the only valid reason to even consider 15w40 is for use in VERY HOT climate but even then most likely not necessary.

Doesn't sound sensible at all.  Heat it up to thicken it up?

aa335 wrote:
Heating the oil would only thin out the oil.

A block heater on a generator?  Sounds like a bit of a quandary.  You'll need electricity to power the block heater.  The generator is there to provide power during an electrical outage?  How does one use the block heater unless you have another smaller unit to power to block heater to heat the C-u-mmins?  By the way, is that a diesel? 

I'd run 10W30 in it if the conditions aren't too cold.  Otherwise, I'd run 5W30 for very cold weather.  Summer time, I'd go with 15W40. 

I put 10w30 in my 8 hp 1986 ariens Tecumseh engine last fall before the weather turned cold, tried to pull start it in 17 degree weather and could barely turn it over. plugged it in and started it and once I was done I drained the oil and replaced it with 5w30. pull starts easier with lighter oil and also starts and runs better after I adjusted the main needle for the colder winter temps vs fall pre winter temps. .

it's not a diesel engine.it's a $#%*mins onan 30k w liquid cooled natural gas gen.It's a gm engine running at 1800 rpm.The engine block heater is to keep I guess the block warm so when the power goes out,it will be prepared to deliver full power in 10 seconds.Otherwise you would have a cold engine trying to del max power before the engine is warm.

Is the block heater on all the time?  If it is, that could add a bit to the hydro bill.....

Sounds like you're now ready for a prolonged power outage provided you've stored enough fuel. 

I've been watching the news about the power outage in Toronto after the ice storm.  Many homes are still without electricity and will likely stay that way until into the new year.  That's the downside of big city living.  Too many high rises unable to supply water, no place to put a generator, no alternative heat source.  Fortunately for us, we have plenty of redundancy here living in the sticks.   Two big high efficiency wood burning fireplaces with two months supply of dry wood, natural gas for cooking/heating water, gravity feed water supply and a couple small generators with lots of fuel and plenty of places to put them.   It easy to be prepared as long as you stay prepared. 

I think you would still have a cold engine with a 10 sec. Start up time... From not running to load would take a hell of a block heater / tank heater. How many watts does this thing burn just sitting keeping it's self warm? I hope for your sake / power bill that the thing has a thermostat keeping it from wasteing power. I would read theinfo on the generator and run what it says, they have to warranty it and they have worked out the numbers.

5w30 synthetic is what all my OPE gets generators everything and my stuff seems fine whether its -25 or 90° so but that is what works for me!!!!!