# What Brand Motor Oil do you use in your Lawn Mower?



## Sam23 (May 2, 2018)

*What Brand Motor Oil Do you use in your Lawn Mower?*
1. When it asks for SAE 30 wt.
or
2. When it asks for 10W30 wt.


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## Topcat (Mar 21, 2017)

Royal Purple Synthetic. I do not use straight 30 weight


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## pennstater2005 (Jul 17, 2017)

Castrol GTX. Don't know why. It's just what I've always used in my mowers.


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## Sam23 (May 2, 2018)

1. When it asks for SAE 30 wt. I use *Castrol HD30*
or
2. When it asks for 10W30 wt. I use *Mobil 1 Synthetic 10W30*


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## vuphil (Jun 14, 2018)

Mobil 1 Full Synthetic 10W30


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## MasterMech (Sep 24, 2017)

Sam23 said:


> *What Brand Motor Oil Do you use in your Lawn Mower?*
> 1. When it asks for SAE 30 wt.
> or
> 2. When it asks for 10W30 wt.


AMSOIL SEF (Small Engine Formula) 10W30 for all of It. One of the few synthetics you can buy that provides exceptional wear protection for engines that do not use rollers internally. The ZDDP content is good for those flat tappets and machined bearing surfaces. Plus it's made to take the heat an air-cooled engine can dish out.

I can't think of a good reason to not use 10W30 over a 30wt. They should be a similar viscosity when at operating temps.


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## Green (Dec 24, 2017)

I'm using SAE 30 in warm weather and 10W30 in cool weather in my push mower, or a mix in in between weather, as recommended by the manufacturer. (They also have a few synthetic options listed.)

What is "High detergent 30 weight" (HD30), and where can I get it? It was recommended for a riding mower.


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## Sam23 (May 2, 2018)

@Green You can get Castrol HD30 at the Home Depot.

https://www.homedepot.com/p/CASTROL-32-oz-Heavy-Duty-Motor-Oil-06142/205159567?keyword=motor+oil+hd+30&semanticToken=21040+++%3E++++st%3A%7Bmotor+oil+hd+30%7D%3Ast++cn%3A%7B0%3A0%7D++engine+oil+%7Bproduct%7D30+%7BproductName_nostem%7D++hd+%7Brest%7D+


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## MasterMech (Sep 24, 2017)

Green said:


> I'm using SAE 30 in warm weather and 10W30 in cool weather in my push mower, or a mix in in between weather, as recommended by the manufacturer. (They also have a few synthetic options listed.)
> 
> What is "High detergent 30 weight" (HD30), and where can I get it? It was recommended for a riding mower.


Unless the manufacturer labels it as non-detergent 30wt, it's got plenty of detergent additive. But in all seriousness folks, modern 10W30 is usually the best choice for viscosity.

Automotive oils that say "SN" are actually lacking a lot of the additives that are beneficial to small engines. Look for small engine specific oils or "off-road" marketed oils.


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## wartee (Mar 27, 2018)

I guess I'm old school. I was always taught that multi viscosity oils are actually the lower viscosity with additives to make it act like the higher viscosity at higher temps; thus, 10W30 is 10W oil with additives to increase viscosity to 30W at higher temps. The problem is air cooled small engines operate at such higher temps than other applications that the additives quickly degrade.

I have been running 30W in my small engines for the last 25 years with no problems whatsoever. I buy whatever is on sale. Note - I do change the oil every year; low oil/"worn out" oil will cause failures.


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## MasterMech (Sep 24, 2017)

wartee said:


> I guess I'm old school. I was always taught that multi viscosity oils are actually the lower viscosity with additives to make it act like the higher viscosity at higher temps; thus, 10W30 is 10W oil with additives to increase viscosity to 30W at higher temps. The problem is air cooled small engines operate at such higher temps than other applications that the additives quickly degrade.
> 
> I have been running 30W in my small engines for the last 25 years with no problems whatsoever. I buy whatever is on sale. Note - I do change the oil every year; low oil/"worn out" oil will cause failures.


You're not too far off, multi-visc oils do in fact have plenty of "viscosity index improvers" blended in to increase their viscosity at temperature.

Modern synthetics are more than capable of dealing with the heat found in these engines. But as I mentioned earlier, all modern oils (conv or syn) meeting the SN standard or newer will lack additives that are very beneficial in our small engines.


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## gene_stl (Oct 29, 2017)

I like synthetic oils because they do most of the things that oils do better than non synthetic. Since most small engines only hold one or two quarts it doesn't cost much to use better quality.

I do use straight weight for break in if that is what the manufacturer of the engine specifies. I do observe the engine manufacturers break in interval.

I am not sure the statement that synthetics come from soybeans is correct. I believe synthetics initial feed stock is natural gas. I usually use Mobil One products because they have been around forever. When I bought my current Hustler mower the dealer offered me a deal where I buy Opti synthetic from him and it would double the engine warranty. It probably was a stupid buy because I have never ever had a lubrication related engine failure in 60 years of fooling around with small engines.

I think people worry about this more than is reasonable. Proof is that one of the current lawn mower marketing schemes is "never change your oil" which I have seen at Sears and other big box stores. Any oil meeting American Petroleum Institute standards is going to be more than good enough for the once or twice a week use that most people make of their lawn gear.

Different if you are a turf professional. However I note that there is still non detergent straight weight oil sold for air cooled aircraft engine use. Aircraft engines typically run in the neighborhood of 2000 hours time between overhauls. At high altitude the air has less cooling capacity than on the ground where people are driving their ExMarks. Auto and especially Motorcycle and GoKart racers spend a lot of time and money worrying about engine lube and lube failure but their engines are asked to do things that lawn gear is not in the same ball park with. Lawn mower engines are relatively low compression and low rpm and low power density.

I think the Opti oil I let my Hustler dealer sell me is Snake Oil and I think that most other oil sold by non huge petroleum companies is too. If they had discovered something worthwhile. Exxon/Mobil or BP or Royal Dutch Shell would have coopted it since Petroleum is the largest traded commodity on earth. I used to like Castrol because racers liked it and it had a good magazine article somewhere back in the sixties or seventies and being an airport kid I liked that its name hearkened back to when aircraft and racing oil had castor oil in it. But if you took it into either the chemistry analysis lab or the oil wear analysis lab you would find there is not much difference. I once worked with a machinist who had a job overhauling oil wear testers for Shell's Wood River plant here in St. Louis. This was the mid seventies and he said it hardly made any difference what brand of API approved oil a person used. They were small single cylinder stationary engines.


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## Green (Dec 24, 2017)

@MasterMech, so Penzoil 10W30 (which actually mentions detergents on the label) would be a good choice for a lawn tractor with Briggs OHV engine?


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## Colonel K0rn (Jul 4, 2017)

@gene_stl remember when Quaker State had the gumming up problem in the 80's where it got dubbed "Quaker Sludge"? My dad used to use that brand religiously until he had to replace a motor that was gummed up in the oil valleys completely with that product. I found out later that apparently it had a higher paraffin content than other oils that were being sold, and they apparently had a problem with this. I guess that's always stuck with me through the years. But then again, dad was pouring oil out of cardboard and metal lidded cans  A lot has changed since then.

One thing is for sure, oil loyalties are a lot like truck loyalties. People sure get worked up about them!


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## MasterMech (Sep 24, 2017)

Green said:


> @MasterMech, so Penzoil 10W30 (which actually mentions detergents on the label) would be a good choice for a lawn tractor with Briggs OHV engine?


Should run that engine just fine.


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## ericgautier (Apr 22, 2017)

I've been happy with Rotella 15w40.


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## gene_stl (Oct 29, 2017)

@Colonel K0rn 
I missed the quaker state problem you mentioned. I didn't use Quaker State back then , in those days I used Castrol. But I always wondered if I was making a mistake because I think the people that owned the Pennsylvania oil fields circulated rumors that their oil was "sweeter" than Saudi crude I am sure to get people to buy it. The carboard cans were lined with foil.
Things do change for sure. I just make sure there is an API symbol on the jug and don't worry about it too much more than that. I do reach for synthetics but I don't think it makes any real difference. And after the break in interval I am pretty flip about change intervals. I do look at what I can see on the dipstick.


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## massgrass (Aug 17, 2017)

Sounds like a discussion over at bobistheoilguy.com.  I've always used whatever dino oil is the cheapest, which has been Walmart SuperTech of late. That includes a 20 year old Deere tractor with a Kohler engine and 10+ year old LawnBoy push mower and an Ariens snow blower with Tecumseh engines.


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## gene_stl (Oct 29, 2017)

The Kohler powered orange monster pictured above had a proper oil change at break in time. It has lived outside since 1999 usually under a riding mower cover (not always). It has about 500 hours. It probably has had four oil changes. Runs great. What it needs is a new muffler. It has blown and rusted out all the packing.Actually what it needs is to be replaced with a John Deere X739 or maybe a Hybrid Triplex! :lol: :lol:


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## kur1j (Jul 2, 2017)

I usually use whatever conventional oil I can find, but I've also only got push mowers.


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## ForsheeMS (May 21, 2018)

Been used Rotella 5w40 full synthetic in all my stuff for a while now. The viscosity range should work in any type of power equipment out there. It is very good oil at a good price and you can buy it almost anywhere. Synthetic is definitely not necessary but it will offer more protection if things happen to get a little ugly.


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## Paulsprimecuts (Jun 13, 2018)

I use mobile one syn and K and N filters on my Kawasaki engines and the kolher oil and filter on the kolher


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## kaptain_zero (Jun 2, 2018)

I just sold my 30+ year old Jacobsen Super Bagger 21" that ran fine on conventional 10w-30 (B&S Quantum engine). It was still a 1 to 2 pull start when I sold it, but compression was starting to drop.

I expect my new Toro to last me until I don't need a mower anymore, using conventional motor oil. I just make sure it has the recommended API grade and call it good enough. Synthetics last longer, but without filtration, I prefer to change the oil at the normal recommended intervals. I just picked up a large jug of Penzoil 10w-30 that should last me close to 10 years.

The best oil on the planet will never make up for failing to service the engine at the correct intervals, so I see no reason to spend the extra money on a lawn mower.

In my snowblower on the otherhand, I always use 0w-30 synthetic, for ease of starting and good lubrication at -40 temps. And yes, the blower is 30+ years old too. Actually, I prefer 0w-30 synthetic in my car during the winter.... just in case I have to leave it parked for an extended period in the cold without shelter or having the block heater plugged in.


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## OutdoorEnvy (Sep 27, 2017)

I use Quaker State and Super Tech Walmart brand mostly cause it's readily available. Haven't had any problems with either. I think just staying on top of oil changes is the important thing. Not the brand. Only dirty or old oil causes problems. Keep up with it and any will be fine.


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## Stegs (Aug 29, 2017)

Amsoil premium protection full synthetic 10w30 with zinc.

Runs in all my 4 stroke small engines. I like to have high levels of zinc to protect these small engines. The lack of zinc is what slowly zaps power from these engines.

I run this same oil in my 69 charger as well, so i buy it in cases

I do amsoil saber 2 stroke mix in all my 2 cycle engines because i can mix it to 100:1 ( i mix it to 80:1)

I do have mobil 1 5w30 full synthetic high mileage in my golf cart, but that will be switch to amsoil next time i make a purchase


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## kaptain_zero (Jun 2, 2018)

So, just to clarify *my* position on small engines and oil. I use conventional oil in my lawnmower that only runs during warmer weather and synthetic in my snow blower for ease of start and good lubrication in our very cold winter weather.

As my province tends to have rather cool springs and falls, I go with a 10w-30 oil for better starting and lubrication in cooler weather. If I lived further south, I would be happy to use straight 30 weight detergent oil (which is not the same as "non-detergent machine oil used for lubricating machinery like lathes and milling machines).

Briggs and Stratton have weighed in on the subject with this:



> Should I use synthetic or conventional (regular) oil in my 4-Cycle Briggs & Stratton Engine?
> 
> Our engines are designed to run on conventional oil, full synthetic, or synthetic blends. It's an owner's personal decision if the extra cost is worth the additional benefits synthetic oils offer. When a customer calls the Answer Center, we recommend the synthetic as it offers the premium protections we talked about earlier.


And then:



> "Does using a synthetic oil change how often I need to change or check my oil or break-in procedures?"
> 
> This is a common misperception of using synthetics in smaller engine. You need to continue your maintenance as stated in your owner's manual regardless of the oil used.


I seem to recall reading somewhere (I *think* on Toro's website) where it was suggested that due to the size of such single cylinder mower motors and the like, there was little benefit to using synthetic oil, unlike a car engine where your oil is continually filtered and you can allow for a longer interval between oil changes to take better advantage of a synthetic oil.

The fact that you cannot extend the oil change interval on a small engine, which is due in part to the lack of an inline oil filter and that it does not use a pressurized lubrication system minimizes any advantage of the synthetic oils and clearly makes maintanence more costly for little benefit, in my opinion.

Either oil works just fine if you stick to the maintanance shedule. If you increase the time between oil changes because you are using a Synthetic oil, you are not getting the dirt and junk out of your engine (I'm not talking about gums and such, but rather dirt and dust that makes it past the air filter and metal particles from wear and tear) often enough.

Check the manual for your engine and ensure that what you use meets the specified grade and API designation.

Regards

Christian


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