I have been trying to decide which engine oil to buy for my generator tomorrow when I go into town and, have concluded, that down this path madness doth lie!
It is a 3kW four stroke generator of 180cc and the manual specifies:
"4 stroke motor oil, SAE 30W or SAE 15W-40"
For the past few months I have been using Penrite semi syn. 10W-40 mainly 'cause Autobarn had a special of 6L for $30!
Now it's time to buy more oil and the Penrite is no longer on special. The gen is not a high performance engine and I suspect would run on almost any old oil but I would like your advice please.
How long has it taken you to use the 6L? My preference would be to stick with what you have been using.
Regards,
Greg 1 said
03:18 PM May 13, 2021
Since you have already been using a semi synthetic oil I would remain with that and go with oil 2.
KJB said
03:26 PM May 13, 2021
Oil 2 - ( I hope I do not cause too much unrest by publicly assisting a fellow Gen Set owner......)
Detecta said
03:33 PM May 13, 2021
Definitely go the SAE 30 Mineral Oil in a generator engine and leave the heavier SAE 40 grade oils for car engines. SAE 30 lubricates a small engine more efficiently and runs cooler.
If you do change oil type - ensure you drain thoroughly and flush crankcase prior to putting in a different oil - My choice is Nulon Full Synthetic 5W-30 Fuel Efficient Engine Oil is specifically designed for fuel efficiency with improved wear protection and sludge handling.
Not the cheapest just the best IMHO.
Benefits
Provides maximum cold-start protection
Added Moly DTC provides additional protection over standard engine oil alone
Outstanding wear protection during stop-start
Energy and fuel conserving formula
High-quality detergents and dispersants reduce internal engine deposits
High shear stable polymers ensure oil stays in spec for longer
Jaahn said
05:48 PM May 13, 2021
Hi Mike
Don't sweat the small stuff !! Buy whichever is the first one through the door !! I had a small engine shop years ago and the only important thing is to make sure there is oil in there and it does not run out and you change it every now and again. There are no important high wear parts in them and the revs are lowish. Gees !!
There is a lot of BS spouted by the makers to protect their patch. As I have said before you can buy Tractor oil universal in drums which is rated for most 'normal' engines, gearboxes, hydraulics, and other things that do not specify particular specs. I have put that in small engines and the tractors and machinery and cars and light trucks in places I worked with zero problems. So oil specs is mostly BS IMHO.
Cheers jaahn
You can stick with Penrite ! http://penriteoil.com.au/products/universal-farm-oil-15w-40-stou
Universal Farm Oil is a premium mineralSuper Tractor Oil Universal (STOU) manufactured from highly refined base oils and advanced multi-functional additives. It is a multi purpose product for use in a wide range of machines and covers multiple applications.
APPLICATION
Universal Farm Oil is designed for use in 4 stroke naturally aspirated & turbo charged diesel and petrol engines, transmissions, front & rear axles, differentials, wet brakes, hydraulics, Power Take Off (PTO) clutches and some final drives of farm tractors and construction equipment.
Universal Farm Oil can be used where 15W-40, 20W-40 and 15W-30 grade oils are specified or where SAE 80W or SAE 90 grade gear oils are specified.
Universal Farm Oil reduces inventory holding as one oil can be used for most applications, also lessening the chance of mis-application.
Universal Farm Oil can reduce wet brake squawk in rear axles where normal tractor transmission oils have been used previously.
Universal Farm Oil can be used in many diesel engines (up to APICG-4 performance)
-- Edited by Jaahn on Thursday 13th of May 2021 06:43:53 PM
oldbloke said
08:18 PM May 13, 2021
Jaahn wrote:
Hi Mike
Don't sweat the small stuff !! Buy whichever is the first one through the door !! I had a small engine shop years ago and the only important thing is to make sure there is oil in there and it does not run out and you change it every now and again. There are no important high wear parts in them and the revs are lowish. Gees !!
There is a lot of BS spouted by the makers to protect their patch. As I have said before you can buy Tractor oil universal in drums which is rated for most 'normal' engines, gearboxes, hydraulics, and other things that do not specify particular specs. I have put that in small engines and the tractors and machinery and cars and light trucks in places I worked with zero problems. So oil specs is mostly BS IMHO.
Cheers jaahn
Agree 100% It ain't a race car. x motor mechanic here.
Aus-Kiwi said
10:33 PM May 13, 2021
Ive used the same as I put in the diesel . Nulon
15/40 . Replace it every year .,
Mike Harding said
06:55 AM May 14, 2021
Thank you everyone for your contributions.
Now... where's that coin? :)
boab said
08:50 AM May 14, 2021
why not just use what the book recommends they would know the requirements better than any of us
Aus-Kiwi said
08:58 AM May 14, 2021
They usually recommend single visc oils . Multi visc oils do a far better job. One good part about diesel oil . It contains zink which is a friction modifier .
Mike Harding said
09:00 AM May 14, 2021
boab wrote:
why not just use what the book recommends they would know the requirements better than any of us
You do not understand my question: there are many types of oil which meet the engine manufacturer's specification - which one of them do you suggest I use?
peter67 said
09:14 AM May 14, 2021
Do what the weather forecasters do and set the dart board up.
Les Bishop said
08:02 AM May 16, 2021
Use a mono grade oil it will be far superior to the multi grade . More goodies in mono grade - multi grades developed for oems to keep service costs down . Multi grade is achieved by adding to the base content volume 25% microscopic plastic coils which are temperature controlled to unwind and rewind to control oil rating. Dont believe me ask an oil engineer
Aus-Kiwi said
03:13 PM May 16, 2021
Oils aint oils !! Generators generally ( in my case ) get started for short periods . Plus Im not buying seperate oil . 20 years I have had no issues . The main thing is to keep changing the oil !!!
Warren-Pat_01 said
11:35 PM May 16, 2021
G'day Mike,
Like a couple of newish members above, I would have suggested the SAE30 as that is what is generally recommended in small stationary engines. What does your hand book say?
My generator (for cyclone use) has a sticker near the oil filler point showing to use the SAE30 oil.
Jaahn said
09:56 AM May 17, 2021
Les Bishop wrote:
Use a mono grade oil it will be far superior to the multi grade . More goodies in mono grade - multi grades developed for oems to keep service costs down . Multi grade is achieved by adding to the base content volume 25% microscopic plastic coils which are temperature controlled to unwind and rewind to control oil rating. Dont believe me ask an oil engineer
Hi Les
With all due respect that is rubbish IMHO. Small engines will run on any reasonable oil and I challenge any person to tell the difference in life or wear. And I have seen inside hundreds of them. While it is true B&S always recommended single grade oils from long ago when multi grade oil was a new idea I have never seen any technical reason to use it or reasons to condemn multigrade oil either.
In some other countries they winterise their engines and store them but I do not believe we need to do that here. Just change it and make sure there is always a minimum level of oil in the sump so the oil splash system works as designed. They will stop if the oil runs low and a low oil level safety cutout is more important than the type of oil.
Jaahn
KJB said
11:03 AM May 17, 2021
Well said Jaahn. I have used a multitude of "small air cooled " engines (Honda , Tecumseh, Mitsubishi, Robin , B and S , BSA , Wisconsin ) over the past 55 years, all worked hard in all sorts of conditions . They got no special treatment - oil changed regularly ,but used whatever oil was convenient (generally multigrade diesel truck/tractor oil) I never had a mechanical problem with any of them . Any of those engines would have thought they were in heaven if they only had to power a Gen Set for a caravan - "easy- peasy" ........
I have been trying to decide which engine oil to buy for my generator tomorrow when I go into town and, have concluded, that down this path madness doth lie!
It is a 3kW four stroke generator of 180cc and the manual specifies:
"4 stroke motor oil, SAE 30W or SAE 15W-40"
For the past few months I have been using Penrite semi syn. 10W-40 mainly 'cause Autobarn had a special of 6L for $30!
Now it's time to buy more oil and the Penrite is no longer on special. The gen is not a high performance engine and I suspect would run on almost any old oil but I would like your advice please.
I've narrowed it down to:
Oil 1
Oil 2
Or should I go for something else?
G'Day Mike,
How long has it taken you to use the 6L? My preference would be to stick with what you have been using.
Regards,
Oil 2 - ( I hope I do not cause too much unrest by publicly assisting a fellow Gen Set owner......)
Definitely go the SAE 30 Mineral Oil in a generator engine and leave the heavier SAE 40 grade oils for car engines. SAE 30 lubricates a small engine more efficiently and runs cooler.
www.penriteoil.com.au/products/small-engine-4-stroke-10w-30-semi-syn
Not the cheapest just the best IMHO.
Benefits
Provides maximum cold-start protection
Added Moly DTC provides additional protection over standard engine oil alone
Outstanding wear protection during stop-start
Energy and fuel conserving formula
High-quality detergents and dispersants reduce internal engine deposits
High shear stable polymers ensure oil stays in spec for longer
Hi Mike
Don't sweat the small stuff !! Buy whichever is the first one through the door !! I had a small engine shop years ago and the only important thing is to make sure there is oil in there and it does not run out and you change it every now and again. There are no important high wear parts in them and the revs are lowish. Gees !!

There is a lot of BS spouted by the makers to protect their patch. As I have said before you can buy Tractor oil universal in drums which is rated for most 'normal' engines, gearboxes, hydraulics, and other things that do not specify particular specs. I have put that in small engines and the tractors and machinery and cars and light trucks in places I worked with zero problems. So oil specs is mostly BS IMHO.
Cheers jaahn
You can stick with Penrite ! http://penriteoil.com.au/products/universal-farm-oil-15w-40-stou
Universal Farm Oil is a premium mineral Super Tractor Oil Universal (STOU) manufactured from highly refined base oils and advanced multi-functional additives. It is a multi purpose product for use in a wide range of machines and covers multiple applications.
APPLICATION
Universal Farm Oil is designed for use in 4 stroke naturally aspirated & turbo charged diesel and petrol engines, transmissions, front & rear axles, differentials, wet brakes, hydraulics, Power Take Off (PTO) clutches and some final drives of farm tractors and construction equipment.
Universal Farm Oil can be used where 15W-40, 20W-40 and 15W-30 grade oils are specified or where SAE 80W or SAE 90 grade gear oils are specified.
Universal Farm Oil reduces inventory holding as one oil can be used for most applications, also lessening the chance of mis-application.
Universal Farm Oil can reduce wet brake squawk in rear axles where normal tractor transmission oils have been used previously.
Universal Farm Oil can be used in many diesel engines (up to API CG-4 performance)
-- Edited by Jaahn on Thursday 13th of May 2021 06:43:53 PM
Agree 100% It ain't a race car. x motor mechanic here.
15/40 . Replace it every year .,
Thank you everyone for your contributions.
Now... where's that coin? :)
You do not understand my question: there are many types of oil which meet the engine manufacturer's specification - which one of them do you suggest I use?
Like a couple of newish members above, I would have suggested the SAE30 as that is what is generally recommended in small stationary engines. What does your hand book say?
My generator (for cyclone use) has a sticker near the oil filler point showing to use the SAE30 oil.
Hi Les
With all due respect that is rubbish IMHO
. Small engines will run on any reasonable oil and I challenge any person to tell the difference in life or wear. And I have seen inside hundreds of them. While it is true B&S always recommended single grade oils from long ago when multi grade oil was a new idea I have never seen any technical reason to use it or reasons to condemn multigrade oil either.
In some other countries they winterise their engines and store them but I do not believe we need to do that here. Just change it and make sure there is always a minimum level of oil in the sump so the oil splash system works as designed. They will stop if the oil runs low and a low oil level safety cutout is more important than the type of oil.
Jaahn
Well said Jaahn. I have used a multitude of "small air cooled " engines (Honda , Tecumseh, Mitsubishi, Robin , B and S , BSA , Wisconsin ) over the past 55 years, all worked hard in all sorts of conditions . They got no special treatment - oil changed regularly ,but used whatever oil was convenient (generally multigrade diesel truck/tractor oil) I never had a mechanical problem with any of them . Any of those engines would have thought they were in heaven if they only had to power a Gen Set for a caravan - "easy- peasy" ........