OPE -> 5W-30 Synth

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Ashful

Minister of Fire
Mar 7, 2012
20,075
Philadelphia
It's coming up on the time of year I cycle thru all of my outdoor power equipment (OPE), doing the yearly maintenance and fluid changes. I'm thinking that, instead of keeping track of all the SAE 30's, 5W-30's,10W-30's, and others, it might be time to just switch everything to 5W-30 synthetic.

Advice?

Limitations?

I figure I'll be keeping the diesel (15W-40) on dino juice, unless someone makes a convincing argument otherwise.

Thanks!
 
Years ago, I was discussing this with a mechanic friend while he was helping me rebuild a carburator and consume some beverages. I wondered if he thought regular or synthetic, 5000 miles or 1 year?

He tells his customers to do whatever their book says. For his engines, once the engine is broken in, it's full synthetic, a good filter with a magnet, and an oil change schedule of never again. When pressed, he said maybe again at 100,000, but he generally didn't change his oil because he didn't see much difference inside at rebuild time.

Since then, I've leaned more and more towards his thinking. No disasters or even piston rings needed yet. :)

Of course I agree that it makes sense to have as little abrasive grit as possible in your piston lube, but until the filter starts losing effectiveness, how much good are you actually doing?
 
He may change filters more often than oil.

The wife's car requires synthetic.

I run synthetic in the snowblower. My 60s outboards, well, all my 2 cycles, get synthetic 2 stroke oil. My beater truck and the lawnmower get dino. A seldom used leaf shredder burns oil so fast I put used oil in. It doesn't leak, plug stays clean... no idea where it goes, but every time it's used I drop a quart.

As far as your engines go, as long as they call for a 30 weight oil and don't see crazy abuse like a snowblower you can probably use a mixed weight in them. Once warm, a 10-30 and a 5-30 are supposed to act the same.
 
Changing oil is more than just getting rid of dirt...its getting rid of acids, renewing oil additives (especially modern oils)
I don't buy the "change the filter and top off the oil" plan. Now that said, I also do not change oil every 3000 miles either...I tend to follow the oil change monitor that most modern vehicles have...our Honda Odyssey usually turns the light on around 9-10K miles.

Now, to OPs question...I use SAE 30 in almost nothing anymore, 15W-40 in the diesel is a good plan, 5W-30 synthetic in everything else should be fine (OPE)...the only thing I could think of that would warrant anything "heavier" would possibly be an air cooled engine that gets run VERY hard in high temps. My 2 cents...
 
Changing oil is more than just getting rid of dirt...its getting rid of acids, renewing oil additives (especially modern oils)
I don't buy the "change the filter and top off the oil" plan. Now that said, I also do not change oil every 3000 miles either...I tend to follow the oil change monitor that most modern vehicles have...our Honda Odyssey usually turns the light on around 9-10K miles.

Now, to OPs question...I use SAE 30 in almost nothing anymore, 15W-40 in the diesel is a good plan, 5W-30 synthetic in everything else should be fine (OPE)...the only thing I could think of that would warrant anything "heavier" would possibly be an air cooled engine that gets run VERY hard in high temps. My 2 cents...
Thanks. Yes, this is OPE only, not cars, guys!

I have one air-cooled engine that gets run hard in high temps. That's the Kawasaki V-twin on my 757 ZTrak. But even that only calls for 10W-30 dino juice. I was planning on switching it to 5W-30 synth, unless someone says otherwise.

Years ago, I was discussing this with a mechanic friend while he was helping me rebuild a carburator and consume some beverages. I wondered if he thought regular or synthetic, 5000 miles or 1 year?

He tells his customers to do whatever their book says. For his engines, once the engine is broken in, it's full synthetic, a good filter with a magnet, and an oil change schedule of never again. When pressed, he said maybe again at 100,000, but he generally didn't change his oil because he didn't see much difference inside at rebuild time.

Since then, I've leaned more and more towards his thinking. No disasters or even piston rings needed yet. :)

Of course I agree that it makes sense to have as little abrasive grit as possible in your piston lube, but until the filter starts losing effectiveness, how much good are you actually doing?
More power to you, but as long as an oil change costs one one-thoustandth the price of a car and takes me under 20 minutes start to finish, I'll keep doing them. I used to rebuild motors, too, and my experience does not agree with your mechanic's. Lots of stuff that looked like this:

[Hearth.com] OPE -> 5W-30 Synth [Hearth.com] OPE -> 5W-30 Synth

Synthetic may be the game changer, here. But I still feel better changing it, and getting all those corrosive combustion byproducts out of the crankcase.
 
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I run synthetic 5W-30 in my outdoor equipment; the splitter, the 48” walk behind mower, and the snowblower. And in my vehicles, but that is what the manufacturer happens to recommend for them. My oil change schedule is 6 months and 6,000 miles. The additives in the oil breaks down over time and they need to be changed at some interval.


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I’m doing my OPE on a yearly schedule, but other than the compact utility tractor (diesel 15w-40), each is used only six months of the year. So, I guess it’s an effective six month change.

Cars are another matter. I have a car that’s only driven in nice weather, and another that’s only driven when it’s nasty, and sometimes one will see less than 2000 miles per year. Those ones get a yearly change at inspection, if they don’t come due on mileage first. You’re saying I should step up to 6 months on those, even with full synthetic?

Having SAE in your name gives you an air of credibility, on this subject. [emoji12]
 
Changing oil is more than just getting rid of dirt...its getting rid of acids, renewing oil additives (especially modern oils)
I don't buy the "change the filter and top off the oil" plan. Now that said, I also do not change oil every 3000 miles either...I tend to follow the oil change monitor that most modern vehicles have...our Honda Odyssey usually turns the light on around 9-10K miles.

Now, to OPs question...I use SAE 30 in almost nothing anymore, 15W-40 in the diesel is a good plan, 5W-30 synthetic in everything else should be fine (OPE)...the only thing I could think of that would warrant anything "heavier" would possibly be an air cooled engine that gets run VERY hard in high temps. My 2 cents...

I fully agree with this. I'll also add that oil does oxidize and lose lubricity. Both synthetic and dino oil will break down with age. Also, the viscosity grade rating tends to diminish as the oil breaks down. The 5W-30 will eventually become 5W-20 and so on. Cheap insurance to change it.

5w-30 across the board will be fine.
 
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So here is a trivia question for you all! Ill respond back with the correct answer the end of the day.

If your engine oil get over heated, say really hot, like 300f. Which oil would protect the best, regardless of synthetic or not, a straight 30w or a 5-30w?

Looking forward to the answers and reasons why.....

I was asked this question in a seminar by oil chemist Ed Collins who worked on aviation oil air shell and exon.


Sent from my iPhone using Tapatalk Pro
 
So here is a trivia question for you all! Ill respond back with the correct answer the end of the day.

If your engine oil get over heated, say really hot, like 300f. Which oil would protect the best, regardless of synthetic or not, a straight 30w or a 5-30w?

Looking forward to the answers and reasons why.....

I was asked this question in a seminar by oil chemist Ed Collins who worked on aviation oil air shell and exon.


Sent from my iPhone using Tapatalk Pro
The multi weight oils provide less protection. The viscosity improving additives can shear back under pressure and high heat conditions causing sludging and a reduction in the viscosity of the oil.
 
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I use multi-weight non-synthetic oil in all my OPE and change yearly.
If I were pushing to multi-year changes I'd probably use a synthetic but I don't think the extra cost is warranted for yearly changes.
An exception: my 32 HP diesel tractor gets changes according to the hour meter - still multi-weight oil though.
 
I use multi-weight non-synthetic oil in all my OPE and change yearly.
If I were pushing to multi-year changes I'd probably use a synthetic but I don't think the extra cost is warranted for yearly changes.
An exception: my 32 HP diesel tractor gets changes according to the hour meter - still multi-weight oil though.

“Extra cost”? We’re talking literally less than $2 difference, for the quart volume that most OPE requires, when purchased in the typical gallon jugs.
 
“Extra cost”? We’re talking literally less than $2 difference, for the quart volume that most OPE requires, when purchased in the typical gallon jugs.
I have at least 15 infernal combustion engines on OPE to maintain though. Some take quite a bit of oil, my JD ZTR for one, which uses the engine oil for the hydraulic drive (common sump). For the oil brand I buy its about $2/quart difference. I'm surprised its that low actually.
I'm willing to pay more, always buy the best of many things. I don't want to spend money where there's no benefit though.
I also remember the early days of synthetics where engines run on conventional oils would leak at the seals when synthetics were used - still a bit wary in that regard since most of my OPE was purchased used. The costs of synthetics have come down a lot also. I think Mobil 1 was about $15/quart when introduced and when conventional oil cost about $1/quart.
I get your point though. This thread may well convince me to go synthetic.
 
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I’m doing my OPE on a yearly schedule, but other than the compact utility tractor (diesel 15w-40), each is used only six months of the year. So, I guess it’s an effective six month change.

Cars are another matter. I have a car that’s only driven in nice weather, and another that’s only driven when it’s nasty, and sometimes one will see less than 2000 miles per year. Those ones get a yearly change at inspection, if they don’t come due on mileage first. You’re saying I should step up to 6 months on those, even with full synthetic?

Having SAE in your name gives you an air of credibility, on this subject. [emoji12]

Well, not to disappoint, but sae is not a reference to Society of Automotive Engineers, but rather my college fraternity. And my last name is Wood, so Woody was a common nickname (plus it works perfectly on this forum!). I’ve been using this as a screen name for almost 20 years.

You can probably continue to get away with your yearly oil changes. It’s really the heat that is going to cause the oil to break down. But it wouldn’t hurt to make sure you get the engine up to operating temperature and running it for a bit if the car isn’t getting driven much; you want to keep the condensation at bay. The engine heat is what evaporates it.

So here is a trivia question for you all! Ill respond back with the correct answer the end of the day.

If your engine oil get over heated, say really hot, like 300f. Which oil would protect the best, regardless of synthetic or not, a straight 30w or a 5-30w?

Looking forward to the answers and reasons why.....

I was asked this question in a seminar by oil chemist Ed Collins who worked on aviation oil air shell and exon.

Interesting question. My gut response is the straight 30 weight. I would imagine that as it gets overheated and starts to break down it will have more viscosity left to it to help protect the engine. But who knows. That’s why these types of questions are fun. Looking forward to the answer.

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Thanks. Yes, this is OPE only, not cars, guys!

I have one air-cooled engine that gets run hard in high temps. That's the Kawasaki V-twin on my 757 ZTrak. But even that only calls for 10W-30 dino juice. I was planning on switching it to 5W-30 synth, unless someone says otherwise.


More power to you, but as long as an oil change costs one one-thoustandth the price of a car and takes me under 20 minutes start to finish, I'll keep doing them. I used to rebuild motors, too, and my experience does not agree with your mechanic's. Lots of stuff that looked like this:

View attachment 221408 View attachment 221409

Synthetic may be the game changer, here. But I still feel better changing it, and getting all those corrosive combustion byproducts out of the crankcase.

I fully agree. I did the timing chains on my 97 Ford Explorer at 205,000 (in 2008) and valve cover gaskets on my 03 Suburban at 215,000 (this summer) and there was zero sludge in either of those motors. Each had regular synthetic oil changes. Helped my BIL do a head gasket, timing chain, etc on his trailblazer and it was disgusting, but not quite as bad as the pics you showed. I know for a fact that truck wasn’t getting regular maintenance, and I’m pretty sure that’s why it was having the problems it that it was. I don’t think it had more than 120,00 on it.


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@Ashful since I switched to synthetic 5w-40 for my diesel truck I starting that stuff in everything. All ope. For many years. Why use all these different weights. Rotella t6.
 
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i've got a 04 5.4 ford that ford wanted to use the 50/50 blend of oil and synt. it was burning a quart every 500 miles i changed to full synt and now have about 1500 miles and still haven't added any. and that's 5w20
 
So here is a trivia question for you all! Ill respond back with the correct answer the end of the day.

If your engine oil get over heated, say really hot, like 300f. Which oil would protect the best, regardless of synthetic or not, a straight 30w or a 5-30w?

Looking forward to the answers and reasons why.....

I was asked this question in a seminar by oil chemist Ed Collins who worked on aviation oil air shell and exon.


Sent from my iPhone using Tapatalk Pro


Ok and the answer is the multi-viscosity oil wins!
You have to think of it as a 5w-30 starts as a 5w but thins at a slower rate. At 100c it is the same as a straight 30w, thanks to viscosity modifiers.
If the oil is overheated and continues to rise in temperature the 5w-30 oil still continues to thin at a slower rate than the straight 30w.

Which means at 150c the 5w-30 oil is thicker than the straight 30w, and therefore able to do a better job protecting from metal to metal contact.


Almost all of engine wear occurs on start up so the thinner oil at cold temperatures allows the oil to get to the right places quicker.

There are 2 drawback to multi viscosity weight oils. 1st during times of long term storage they do not cling on surfaces (cylinder walls, cam lines ect.) as well as straight weight oils. Remember as they COOL they thin faster so at room temp they are thinner which is great for cold starts but bad for rust/corrosion protection for storage periods (longer than 30 days)

The 2nd draw back is the long chain viscosity modifying polymer can get sheared it broke in half under extreme heat, cavitation or pressure, but when the oil is changed at the recommend interval this isn’t a issue.

I saw it was posted that these viscosity modifiers cause containment’s or sludge type formations when they are sheared down, but I’ve never seen that in any study.

Anyhow there is the oil facts of the day. Multi-weight really helps protect your engines the best.

Aaron


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Unfortunately they do break down under extreme conditions and the oil thins more than straight weight. This is why serious race motors use a straight weight oil. At what point does thst occur? Idk, it's different for each oil and what base stock they use and what additives they have.

The analogy that they continue to thicken at higher temps (thin less quickly than straight weight) may be valid to a point but people with more knowledge than us also know the property of the oil is not stable under extreme conditions and will break down. So, they go with an oil that is predictable under those conditions which happens to be straight weight. Oils don't normally get tested above 100C. The kinematic viscosity test is standard for 100C and at a lower temp for the W grade. They don't test them at 300F and publish the results. However, it is well know that the more viscosity index (VI) additives the higher probability they will fail and return to the base stock.

So, if I had to sum it up in as few words as possible I'd say there is a practical limit and eventually the inevitable breakdown of multi weight oil will occur before straight weight. That is why straight weight oil is chosen over multigrade for high performance engines.
 
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Great posts, guys.

@semipro, I’m blown away your JD ZTR has a common sump. I own a JD 757 ZTrak, and it has separate hydro (which oddly uses 15W-40 instead of hydro fluid) tank. It holds quite a bit (8 quarts), but it only needs changing every 500 hours, which is several years at my 70 hours per year. The engine oil is only 2 quarts, or thereabouts, which is what I’m changing every year. I also have about 15 ICE’s, some of them rather large (over 6 liters displacement).

@Highbeam, I’ve been reading up on this, and it seems most manufacturers recommend keeping the same recommended weight, when going from Dino to synthetic. If following this, I’d still have the headache of stocking multiple weights, and trying to remember which to use, when a machine needs topped off. My initial attraction to synthetic was an assumption I could just switch all my SAE 30’s, 5W-30’s, and 10W30’s to synthetic 5W-30.

@semipro, re seals: yeah, I’ve read several accounts of seals leaking on older machines, when switching to synthetic. Another reason to keep my old JD 855 diesel on the Dino juice.
 
Yep, switch everything to 5-40 since the viscosity requirements of just about every engine made falls within that range. Remember those charts in the owners manuals with the temperature on on the y axis and the protection range of each oil? The 5-40 does it all.

It really is your solution to keeping separate oils on hand.
 
i'm losing something in the translation i read that oil will get thick when hot anyone ever try and pour a bottle of straight 50 at 20 degrees
 
i'm losing something in the translation i read that oil will get thick when hot anyone ever try and pour a bottle of straight 50 at 20 degrees

Hah... yeah, the nomenclature can be confusing. The first number is the viscosity of the oil it will match when they’re both cold, and the second number is the viscosity of the oil it will match when they’re both at rated temperature. So, 5W-30 will match SAE 5 when they’re both cold, and it will match SAE 30 when they’re both hot. The thing you’re missing is that hot SAE 30 has lower viscosity than cold SAE 5.
 
i'm losing something in the translation i read that oil will get thick when hot anyone ever try and pour a bottle of straight 50 at 20 degrees
It's convoluted. Overall, all oil does thicken when it gets colder. However, a multi grade oil like a 20W-50 will pour like a 20 weight oil at the colder temp but pours like a 50 weight oil at 100c. So therefore the oil technically "thickens" as it gets warmer despite the fact that 100c oil even at 100c probably pours like water and 5c pours like molasses.

The question about what provides better protection at say 300f really highlights the multi grade oils ability to change its viscosity which is heat dependant. The more heat the higher viscosity (up to a practical limit).

Straight weight oil does not undergo a change in viscosity with change in temperature.

Clear as mud?