Specific questions about car oil in B&S

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May 17, 2006
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Air cooled OPE engines run pretty hot if used for very long.
Oil can get to 230-250°. Conventional oil starts breaking down at that temp.
Synthetic oil hold up to the heat better.
10W-40, 5W-40, 15W-40, etc. are all good oil weights to use. Synthetic of course.

My 2¢
 
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Feb 8, 2019
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WA
Answers:
1.yes
1.1no
1.2no
1.3NO. the motorcycle oil has goodies in it for the wet clutch set up usually found in bike engine crankcase. You have none of that.
2.YES
2.1. Ask B&S tech line.
3. the engine code you name is 'splash lubricated', there's no oil pump moving lube inside the crankcase. The thicker starting viscosity is what's needed for these, because that engine is essentially stationary & the fan & shrouding is keeping it cool. B&S specified a thicker oil to protect it best.
Also, I can't recall any B&S engine manual that ever advised something that sounded stupid or unreasonable as far as making one of their products last & perform as long as possible. If they spec 15w-50, there was a good reason their testing proved it to be the best choice.
 
Joined
Oct 6, 2020
Messages
1,025
Answers:
1.yes
1.1no
1.2no
1.3NO. the motorcycle oil has goodies in it for the wet clutch set up usually found in bike engine crankcase. You have none of that.
2.YES
2.1. Ask B&S tech line.
3. the engine code you name is 'splash lubricated', there's no oil pump moving lube inside the crankcase. The thicker starting viscosity is what's needed for these, because that engine is essentially stationary & the fan & shrouding is keeping it cool. B&S specified a thicker oil to protect it best.
Also, I can't recall any B&S engine manual that ever advised something that sounded stupid or unreasonable as far as making one of their products last & perform as long as possible. If they spec 15w-50, there was a good reason their testing proved it to be the best choice.
Why can a fully synthetic be bad for the engine?
 

Tjalde

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May 10, 2021
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Thank you again for the overwhelming answers. I will definitely go with a fully synthetic oil; 5w30, 5w40 or 10w40
 
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WV
This is a great thread, comes up now and again, and never gets resolved to any real degree. Know why? Because, as was mentioned, any decent oil will do. I'm trying to shake my ocd'edness about oil, and to some degree it's working.
No truer words were ever spoken than the previous post about no ope engines don't fail because of oil choice, but lack of oil altogether.
I still like HDEO and syn even though my tractor is water cooled, and I have 30wt HDEO in it right now, so I guess I'm not cured. I like it for it's robustness, but heck any old car oil will do.
 
Last edited:

Tjalde

Thread starter
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May 10, 2021
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Of course there are several opportunities (as listed in the manual). I got an answer for my concerns.

There will never be one single solution. But when the price is almost the same, I would like to seek for the best care which in the end may be only a little bit better than the second choice.
A lot of people pass primary school. But that does not mean that they have performed equally.
 
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If it gets hot there is no substitute for viscosity. Physics matters. As for "breaking down" there is no substitute for an oil that carries an approval that has demonstrated oxidation resistance such as MB 229.5 or Porsche A40. An inexpensive oil that meets all of this is either Castrol 0W-40 or Mobil 1 0W-40 both available at Walmart for a low price.
 
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If it gets hot there is no substitute for viscosity. Physics matters. As for "breaking down" there is no substitute for an oil that carries an approval that has demonstrated oxidation resistance such as MB 229.5 or Porsche A40. An inexpensive oil that meets all of this is either Castrol 0W-40 or Mobil 1 0W-40 both available at Walmart for a low price.
So would those 0w40 be better in OPE than a syn 10w30?

I'm still learning :D
 
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So would those 0w40 be better in OPE than a syn 10w30?

I'm still learning :D
Any Euro oil including 0w-40 would be better in OPE than an ILSAC 10w-30. More anti-wear additives, slightly more viscosity and HTHS is especially beneficial for extended use in hot weather.
 
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North Florida
After trying various viscosities in my Kawasaki powered zero turn that uses some oil I have settled a straight 40W SN rated oil from Tractor Supply. I cut in sunny/hot Florida so 40W is specified by Kawasaki as acceptable. Multi weight oils, including 5W-50 used more oil.
 
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May 23, 2021
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Why no one use 0w60 and cover all range?
The winter and summer viscosity do not constitute a "range". Rather, these describe how the oil behaves when very cold, and how it behaves once it is at close to engine operating temperature.

So the 0w can be considered strictly a cold start thing. You can forget about it for a lawn mower, which usually does not get used when it is very cold, so you woudl not benefit from 0w.

The only thing that matters once the engine is up to operating temp, is the second number.

From what I am reading, the 60 summer weight oils are have worse cooling performance than the 50s. AFAIK, no manufacturer of OPE-s recommends "Something"w60. A 0w60 would have to have an insanely high viscosity index, which would pose a challenge, and require severe VI modifier additives, if it is even possible to make.
 
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The winter and summer viscosity do not constitute a "range". Rather, these describe how the oil behaves when very cold, and how it behaves once it is at close to engine operating temperature.

So the 0w can be considered strictly a cold start thing. You can forget about it for a lawn mower, which usually does not get used when it is very cold, so you woudl not benefit from 0w.

The only thing that matters once the engine is up to operating temp, is the second number.

From what I am reading, the 60 summer weight oils are have worse cooling performance than the 50s. AFAIK, no manufacturer of OPE-s recommends "Something"w60. A 0w60 would have to have an insanely high viscosity index, which would pose a challenge, and require severe VI modifier additives, if it is even possible to make.
There are also not a lot of 60 viscos oils
 
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Briggs used to be concerned that dino 5w30 would disappear in the heat. And, apparently, it used to. People don't check the dipsticks like they should and motors were lost as a result. The manual is written based on history. Briggs and GM hate 10w40 because the VII polymers used to shear out and make goo, but this happened 40+ years ago.

I get my oil on sale and always have a 1/2 quart of some ultra premium synthetic laying around that's about the right weight. It either goes in a frankenbrew for a beater car or in OPE.
 
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I always wait to find a quart of Delo or Delvac on sale on a Walmart endcap, and dump that in. Grade doesn't matter I've ran 5w30 10w30 15w40. My briggs Deere self propelled is about 12 years old no issues. Also gets a new Champion plug every year (gasp)
 
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Some folks seem to approach their OPE-s as if they were not worth anything, or if these are the beggars who can't be choosers. "It gets the leftovers". I don't look at it that way. My zt lawnmower is a full member of my small republic of ICE-s. I am probably a fool and OC, but I try to take care of it and my other OPEs as best I can.

So JustinH, why does grade not matter? Please clarify. Are you saying that it does not matter to you, or it does not matter to your OPE?
 
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Some folks seem to approach their OPE-s as if they were not worth anything, or if these are the beggars who can't be choosers. "It gets the leftovers". I don't look at it that way. My zt lawnmower is a full member of my small republic of ICE-s. I am probably a fool and OC, but I try to take care of it and my other OPEs as best I can.

So JustinH, why does grade not matter? Please clarify. Are you saying that it does not matter to you, or it does not matter to your OPE?
It's not that a lawnmower doesn't matter. It's that the simple engine is tolerant of a wide range of oil grades. This makes a lawnmower the perfect vehicle to use up extra oil so that it does not go to waste. To me, this is being environmentally conscience.
 
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