Oil choice for generator

[jsharp]

I'm about ready to do an oil change on my generator and I'm curious about what oil people here would recommend. It's a 5500 watt Coleman with a Briggs and Stratton Vangard 9hp OHV engine. It gets used in the dead of winter in Illinois along with the hottest part of the summer and I want to use the same oil year round. Oil cost isn't an issue since the sump is so small.

Some possible choices -

German Castrol 0W-30
M1 10W-30
M1 15W-50
M1 5w-30 mixed with M1 15W-50 to make a 10W-40
Mobil MX4T 10W-40
Rotella T 5W-40 group III synthentic
Mobil Delvac 1 / Truck & Suv 5W-40
Unlisted choices are fine too.

What would you run and tell my why you'd run that given oil vs. something else...

[ September 06, 2004, 07:24 PM: Message edited by: jsharp ]

 

[Brett Miller]

I would go either with GC 0W30 or Mobil 1 5W-40. They'll both work will year 'round.

 

[Ed]

Seek and ye shall find.

Briggs recommends straight 30 weight.

Thy sell their own brand ,of course.

I would guess that Briggs gets a lot of questions about the use of synthetic oil in their products(as it should be) so GUESS WHAT? They came out with their brand of synthetic. I have no idea which oil co. supplies them but I'm sure it meets with all of the requirements for their engines.\
You can't go wrong with this:
http://shop.briggsandstratton.com/BShopProductPage.asp?CatalogID=56B2B9AE-283C-11D4-8886-00B0D0203414&MECID=100&SessionID=BE674E15-63DF-4A7A-83C5-852DF13C47EF&CategoryID=&lrid=1&Pr oductID=F3696DDE-838C-435A-AA37-43D76A1E5497

 

[Bio-T]

Troy-Bilt generators which are part of the Briggs & Stratton Power Products Group for their 5500 Watt Generator they recommend: 30 weight dino for 40F and above temps, and 5W30 or 10W30 dino below 40 degrees. They note that the use of non-synthetic, multi-viscosity oils (5W30, 10W30) in temperatures above 40F will result in higher than normal oil consumption. Also a note that SAE 30 oil if used below 40F will result in hard starting and possible engine bore damage due to inadequate lubrication.
For all temps from any temp minus 0F to 100F and above they recommend Synthetic 5W30 or 10W30 oil. Any synthetic oil meeting ILSAC GF-2, API certification mark and API service symbol with "SJ/CF ENERGY CONSERVING" or higher is an acceptable oil at all temperatures. Use of synthetic oil does not alter required oil change intervals. These requirements are for all B&S engines in the Troy Built generators from 190cc-342cc engines. (I took all this info from their manual in front of me by B&S)

 

[Bio-T]

I would stick with 5W30 Synthetic oils until the engine starts to use oil, then move to a 5W40 or 0W40. It is a splash system (28 ounces of oil) and my personal choice is an oil with Moly. Some that I like in this type equipment:

Royal Purple 5W30
Synergyn 5W30 (this stuff clings to metal)
Torco 5W30 SR-1
Red Line 5W30

My other choices:
Schaeffer's 5W30 (semi-syn but moly and it is green)
Amsoil 0W30
Mobil I 5W30 (2 ounces of LC added)

I have a 10HP and 13HP riding mower. Also a 10HP Generator and an 11HP pressure washer. At less than 1 quart per fill on all but the 13HP, why go cheap. I don't like replacing these small engines. Also run FP in the fuel, it is a no-brainer to me.

 

[Ugly3]

I have run Mobil 1 in my standby natural gas generator since the mid 80's. Change once a year on the 4th of July. Currently using 5w30, little better for winter starts.

Longest it has run is 4 days - no problem at all.

 

[jsharp]

I'm surprised at how few people recommended a multigrade 40 weight oil. I know Briggs recommends 30 weights but I wonder if that's just a compromise to allow good lubrication when the engine is cold. It seems like these things run pretty high oil temps so I'd think a heavier oil would be good in hot weather.

I've been running M1 10W-30 and haven't seen any consumption but I haven't run it much in very hot weather either...

 

[RJCorazza]

My 14hp Generac very specifically states not to use any xW40 oil. Absent that caution I would have chosen Amsoil 10w40 (which is what I was running in other small engines). Wanting a one or two oil "fleet" I am in the process of switching everything over to Amsoil 5w30 Heavy Duty Diesel.
My second choice (other than Amsoil) would be Mobil 1 5w30.

 

[Bror Jace]

jsharp, going year 'round on the same brand/weight of oil in Illinois in an air-cooled engine is asking a lot ... but not impossible. Is this machine stored inside? What is the coldest air temp this thing will be started in? Got a battery or is it an "armstrong" starter?

How hard (# of hours) is this machine used at any one time? Constantly at high-RPM? Constantly under load?

Assuming that you might have to start this thing in temps as cold as –10F, I’d say a 0W or 5W synthetic (preferably Group IV or V). You might get away with Mobil 1 10W30, though. That stuff pours and pumps at very low temps.

I think one of the things you need to be concerned with is shear stability. No matter what, you don't want to have the oil shear down below a 30 weight at operating temp. I think GC is very shear stable, as is Delvac 1, M1 T&SUV, and Red Line 5W-40. Not so sure about Rotella 5W-40 or many of the other wide-viscosity-spread oils. Maybe search this forum for UOAs and look for signs of shearing. I suppose if you start out with a 40 weight oil and it shears down a bit, you'll still be "in the zone" of a 30 weight and should be OK. So maybe even Mobil 1 0W-40 would be good.

I wouldn't use any weight of Royal Purple (unless one of their heavier racing weights – 15W40?) in an air-cooled engine for just this reason.

I'd opt for GC, Mobil 1 15W-50, Delvac 1, M1 T&SUV, Red Line 5W30, 5W40, Schaeffer 5W-30 ... just change it regularly, especially in the summer, especially if themachine is run very hard and lastly if you notice consumption.

As far as Brigg's factory recommendations, I think they're finally catching up but still put too much emphasis on the word "synthetic." In an age of Group II+ vs. Group III base oils, I don't think there’s a big dividing line between "conventional" and "synthetic" but Briggs treats the issue as if there is.

I suppose it's not entirely their fault. The use of Group III has added all sorts of confusion to the oft-misunderstood world of oils and lubrication. Trying to "dumb down" recommendations for the average consumer presents all sorts of problems.

I know one thing, I'd never bother with B&S branded oil.

--- Bror Jace

 

[jsharp]

RJCorazza - I'm wondering if the warning you're seeing is a leftover from the bad old days of the black death caused by 10W-40 dino oil.

Bror Jace - I know it's asking a lot to work in the temp extremes we have around here but the common usage will be from a high of maybe 85F to low of probably 20F. The unit is recoil start so something too thick would not be good in the winter. But, I do use it in the summer too so going too thin I think will cause problems if it's used hard. To run my house when the power is out takes under 2KW but when something like the well pump is running I'm close to maximum wattage.

I've run it on straight M1 10W-30 and also straight M1 15W-50 in the summer but I dumped the heavy stuff before winter came along. No problems with either in the 100+ hours I've run the unit but the temps were always moderate.

Right now I'm leaning toward an M1 mix to get a heavy 30 weight or GC 0W-30. These decisions were easier before I found this board. I didn't worry about it so much.

I may end up just flipping a coin to decide...