Oil & Common Sense for Small Engines

Messages
5
Location
KY East of Lexington
Like a lot of you I have a "Small Fleet" of "Small Engine, 3.5 to 23 HP". What Oil to use? I want something that will keep these engines running until the rest of the machine falls apart. I have read a lot on here and other places. There are lots of opinions about Oil. Here is what I am planning to do: I am going to pick a Automotive 10W-40 or 10W30 Full Synthetic, Add a liberal dose of ZINC like Roslone Hyperlube. And run it in all my fleet. My Reasoning Full synthetics are not supposed to break down under high heat of a Turbocharger so they should do perfectly well with the temps of a 19 Hp Kohler mower on a 100 degree Ky day. Todays Synthetics appear to eliminate most to almost all internal engine wear these days. The "liberal addition" of of the Zinc should protect against any "flat surface" wear in these engines. So Simple, Common Sense, and relatively cheap. Would really like to hear what ya got to say about this. I have had some really Dumb ideas in my time. If this is one of them please tell me it is dumb.
 
Messages
102
If it were me: I would run a 10w30 synthetic and be happy with it.

Thicker oils work fine, but are not always necessary.
 

JRed

Site Donor 2021
Messages
2,112
Location
Virginia
Rotella T5 10w-30 or regular Rotella 15w-40 in all the small engines up to 35 horsepower. Been doing it this way for 10+ years.

Oil is pretty much never what kills a small engine. A misadjusted/clogged carburetor, intermittent misfire from a bad coil pack, misadjusted valves, etc. are what kill them.
 
Messages
2,568
Location
Caldwell Idaho
Unless you are running commercial, good air filters and proper oil change intervals will keep the engines living long lives. Do you start the engines in freezing weather? A 15W-40 or 10W-30 and even a 20W=50 would work Syn or conventional . Todays oils aren't like the oils 40 years ago.. There aren't high valve train pressures so Zinc isn't an issue. Turbo heat? I doubt many semis , tractors, and ships with turbo engines run syn oil. I have 3 Honda GX 160s .1 Honda HRR , 1 Vanguard 9, and 1 GX390. I use the same HDEO used in the tractor.
 
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Messages
1,506
Location
Warner Robins, GA
My lawn mowers get whatever I have left over from changing cars, which is generally a full or semi-synthetic 5w-30 and I change my rider every couple years (80ish hrs) on my small stuff with 3.5hp - 8 I never change them once I put in some initial decent oil and just keep them topped off.. None of my stuff gets a ton of hrs and I'm very much in the "keeping it full is much more important than what its full of" camp when it comes to OPE. If I was going to pick a dedicated oil for all of them it'd be a full synthetic 10w-30. Probably supertech.
 
Messages
102
My lawn mowers get whatever I have left over from changing cars, which is generally a full or semi-synthetic 5w-30 and I change my rider every couple years (80ish hrs) on my small stuff with 3.5hp - 8 I never change them once I put in some initial decent oil and just keep them topped off.. None of my stuff gets a ton of hrs and I'm very much in the "keeping it full is much more important than what its full of" camp when it comes to OPE. If I was going to pick a dedicated oil for all of them it'd be a full synthetic 10w-30. Probably supertech.
Yes, ST syn 10w30 is a good choice for OPE.
I use it for my oil change on my Super Recycler 4 times a year. Seems to work well.
 
Messages
2,380
Location
Paradise of Florida
I don't think that I've seen any zddp additive improve 'wear rates' when blindly added to oil. Get a formulated oil with a good dose.

My recommendation is a full synthetic oil, but not an automotive oil. Plenty of good 4cycle small engine oils, motorcycle oils, and HDEO's in various grades.

Maybe the SP/GF6 level has enough moly/boron/titanium to make up for the lower ZDDP levels.

Briggs/Honda/HPL/Amsoil/RoyalPurple/RedLine..... are what I use and recommend in my smaller engines.

For motorcycle oils, you can check out the conventional/blends/synths from any brand like Valvoline/Castrol/Mobil available in most of the autopart stores and malwart around here... grade limitations for some climates. And, hdeo's in 5w30, 10w30, 0w40, 5w40, 15w40 are pretty common in the same stores.

Most are lucky not to use their small-engine'd equipment much, or enough, where you might notice a difference in engine life.
 
Messages
2,466
Location
Pennsylvania
I ran an 8 HP Tecumseh on a snowblower for over thirty years. This engine had hundreds of hours on it from doing an entire cul de sac and several driveways every time it snowed. Lots of heavy snows were included in this and that engine really worked hard.

All I ever used was was something like Pennzoil 5W-30 and later in the engines life I switched over to Mobil 1 5W-30. I faithfully changed the oil every spring, greased the wheel bearings and the feeder shaft, put storage fogging oil in the cylinder and then replaced the plug before putting it away. Each winter it started on the first or second pull of the starter rope! I routinely used mid-grade octane fuel in the engine.
 

JRed

Site Donor 2021
Messages
2,112
Location
Virginia
Pro tip
Don't be like the cheap DIY'er and use compressed air to clean out a paper air filter. It will make the filter very porous and allow particles to enter the engine and shorten it's lifespan.

Adding zinc is waste.
I like the guys that use the air gun and blast the dirt on the filter into the filter and call it "good enough" when they can see light through it again. Or wash paper filters as though they're reusable K&Ns or something.
 
Messages
2,584
Location
wv
I think the best bang for the buck would be Mystik 15w50 at Rural King - $12.50 a gallon.

Great UOAs here in Harleys with high heat.

You could pay $10 more a gallon for Mobil 1 15w50 with likely the same results.
 
Messages
180
Location
Northern Michigan
I wouldn’t over think this one...
I have a 1985 Honda lawn mover, which I still mow my lawn with today, and have used whatever oil I had around for my cars...which was Dino oil at first.
 
Messages
13,088
Location
North Carolina
I'm using amsoil AME 15w40 in mine except the generator which is recoil start in cold weather, that gets amsoil hdd 5w30.
I am guilty of using some rislone zddp additive only in my air-cooled ope.
 
Messages
135
Its either I use a straight 30, 15w-40, 10w-40, 10w30, or 20w50.

I wouldn't use 5w20,0w20,0w16,5w30,0w30, 5w40, and 0w40.

The ones i wouldn't use is through testing each one using briggs engines with very high rpms adjusted on my pressure washer and push mower,

the 5w20 after 20 minutes started burning like CRAZY, the 0w20 started burning at startup and created blue smoke you can see everywhere, 0w16 fouled up my plugs, 5w30 ran for 1 hour and then started burning alot, 0w30 fouled up my plug after 4 minutes of runtime, 5w40 seemed promising at the 2 hour mark, but after shutoff was as thin as water, 0w40 started burning alot at startup but then stopped after a minute.
 
Messages
102
Its either I use a straight 30, 15w-40, 10w-40, 10w30, or 20w50.

I wouldn't use 5w20,0w20,0w16,5w30,0w30, 5w40, and 0w40.

The ones i wouldn't use is through testing each one using briggs engines with very high rpms adjusted on my pressure washer and push mower,

the 5w20 after 20 minutes started burning like CRAZY, the 0w20 started burning at startup and created blue smoke you can see everywhere, 0w16 fouled up my plugs, 5w30 ran for 1 hour and then started burning alot, 0w30 fouled up my plug after 4 minutes of runtime, 5w40 seemed promising at the 2 hour mark, but after shutoff was as thin as water, 0w40 started burning alot at startup but then stopped after a minute.
What kind of monster would use 0w20 / 5w20 /0w16 in a small engine 😭
(No offense intended)
 
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