Air cooled engines need the very best oil?

Somehow or another within my wife's family I've become "the guy" for lawnmower maintenance, and I've changed more lawnmower oil and sharpened more blades this year than I probably had in my life up to this point.

Generally they get whatever I have an open quart of, although if I have to buy oil it will be conventional 5W-30 or 10W-30. I've gone as high as 20W-50 before because, well, I have a British car and even if I have no other oil on hand, I'll always have 20W-50. Generally during mowing season it's warm enough here that I don't worry too much about 20W-50 as long as it's not too hard to pull.

Some seem utterly alarmed at what seems a "reckless" disregard for the oil type I'm putting in, but clean and full trumps basically any other consideration.

Which reminds me too-BIL is supposed to bring his tomorrow for a sharpen and oil change. I've definitely gotten good at freehanding them on the bench grinder!

And I'm so grateful too for my own personal push mower(s) where I never have to worry about changing the oil or even checking the oil level :) (plus I cycle through mixed gas a lot faster now than I ever did in the past).
Once you become "the guy" there is no going back. :LOL:
 
Once you become "the guy" there is no going back. :LOL:

I don't mind it too a point.

Of course there comes a time where I'd rather just drop some of the show with it-i.e. BIL says "Will you help me do my brakes." He loses interest pretty much as soon as the wheels come off and I start mostly using hand tools, gets frustrated at how long it's taking me because his 200K mile Camry probably has its factory pads and rotors and the rotors won't come off, and 3 hours later is sitting there watching me scrub brake dust off the calipers with a nylon brush since it's caked on thick(and I'm pretty picky about how I do brakes) and asking me if I "really" need to do all that because he's supposed to be meeting a friend for dinner.

At the end of the day, I wish he'd just said "would you do my brakes for me" and left his car with me for the evening(he could have even driven mine) and let me leave him with a properly done job.

He cancelled on bringing his mower yesterday. I'm going to encourage him to wait until end of the season so I can actually do stuff properly and not have him watching the clock while I scrub grass off and paint the underside of the deck and the like(which reminds me-I need a rattle can of "Grapper Green" which is supposed to match the Lawn Boy paint. One of mine needs a bit of work on the deck beyond just cleaning and painting, so we'll have some fun putting my less-than-great welding skills to use).
 
I would only recommend a good quality oil for OPEs being used hours on end. Like commercial users and generators. Otherwise, if you run it with not many hours for the whole year, than any motor oil will work.
 
I run any left over oil I have from oil changes…at least 30W. Ran 0W30 and 5W30. My GVC 160 runs great in the Texas heat.
 
Is there any advantage to using a straight 30 grade over something like a 10w-30 In a mower that’s only used in warm temps?
 
Is there any advantage to using a straight 30 grade over something like a 10w-30 In a mower that’s only used in warm temps?
I always got a puff of smoke when starting a cold engine using a 10w-30. Never had it using a straight 30. I would say a slight gain in oil consumption using 10w-30.
 
OK then, any reason not to run my rider on a steady diet of an S-rated 15w-40 HDEO? I’ve been using the leftovers from my tractor oil changes for a couple of years and haven’t noticed any difference. Any reason not to make that thr normal fill?
 
Does it make sense to run a really high quality oil in an air cooled engine?
It won't make a difference to spend extra on a small engine. However, low temperature performance is the only excuse for the price if it really gets cold or the engine is frequently cold started on a regular basis during winter. Either way, the 20-25 hours of operation is said to be the green zone for most air-cooled engines as established by many published papers.
ZDDP is not for "flat tappets" only, it's also a potent anti-oxidant and aids oil thermal conductivity and stability. ZDDP is an air-cooled engine's best friend.

Here's some tips for air-cooled engine maintenance.

1. Sufficient oil level is the most important factor.
2. Synthetics do not protect more, it protect the same as mineral oils for longer, unfortunately, you cannot go longer.
3. Change the oil every 20-25 hours.
4. At least ZDDP equal or higher than 1200 ppm. 1400 ppm is optimal.
5. High TBN will also help keep the engine running cleaner with less sludge and deposits formation due to high thermal stress and erratic temperature variations.
 
OK then, any reason not to run my rider on a steady diet of an S-rated 15w-40 HDEO? I’ve been using the leftovers from my tractor oil changes for a couple of years and haven’t noticed any difference. Any reason not to make that thr normal fill?
I've been running 15w40 in small engines for years. Pretty much everything I work on besides snowblowers gets a 15w40.
 
I’v owned a 2014 Royal Enfield Continental GT 535 Cafe 535cc single cylinder air cooled motorcycle since new. Currently I have just over 14,000 miles on it. Living here in Houston, Tx where starting as early as early May to late September, our day time temps are well above 90ºF with humidity 80% +. Since day one I have used Castrol Actevo 4T 20W-50 motorcycle semi synthetic oil which is designed for air cooled engines. Since the 535cc is an air cooled engine, I change the oil every 1,500 miles.

From when I graduated high school in 2000 to June 2017 I was a forklift / heavy equipment mechanic. I also do classic / muscle car restorations on my personal cars. I currently own a 1961 Willys Wagon that Dad bought in 1971. Dad and I did a 9 year compleat frame off, nut-n-bolt restoration on it. A 1965 Volvo B18 PV544 Sport that I bought from my Uncle in April 2014. In August of 2021 I finished an 85% 5 1/2 year restoration on it. 1973 Dodge Dart Swinger that my sister bought in 1994 while in high school. She sold it in 2001. In 2019 I started to look for that ‘73 Dodge Dart Swinger. In February of 2023 I found the ‘73 Dodge Dart Swinger and was able to buy it in May 2024. I’m currently in the beginning stages of starting a full restoration on it. And my first car I bought at age 17 December 1999, a factory original, unrestored, survivor 1979 Hurst/Olds W-30.

Air cooled engines are much harder on engine oil then a liquid cooled engine. They run much hotter which means your engine oil is having to do it’s job at a much higher operating temp. In my strong opinion with my experience, you should be using a high quality motor oil that is designed for air cooled engines. Either a 15W-50 or 20W-50 quality semi / full synthetic air cooled specific motor oil should be used. And because air cooled engines are much harder on the engine oil life span, I highly recommend changing the oil much more often then you would with a liquid cooled engine. I change the oil in my Royal Enfield Continental GT 535 Cafe every 1,500 miles.

Remember, oil is cheep insurance for your engine.

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I always got a puff of smoke when starting a cold engine using a 10w-30. Never had it using a straight 30. I would say a slight gain in oil consumption using 10w-30.
I bought my factory original, unrestored, survivor 1979 Hurst/Olds W-30 with the Oldsmobile L34 “R” code 350, back when I was 17 in December of ‘99. Since day 1 I have used Royal Purple with zinc 10W-30 full synthetic oil with zero issues. I change the oil every 2,000 miles or once a year which ever comes first.

In August of ‘21 I completed an 85% + restoration on my 1965 Volvo B18 PV544 Sport with the factory B18B rally racing higher horse / compression twin S.U. HS6 carb 1800cc engine. I’v been using the same Royal Purple 10W-30 with zinc full synthetic oil with zero issues. Again, changing the oil every 2,000 miles or once a year which ever comes first.

In May 2024 I bought a 1973 Dodge Dart Swinger with the factory 225 Slant Six. The 225 has the factory optional “Hyper Pak” installed. The Hyper Pac has a 4 bbl carb, aluminum performance intake manifold and several other performance enhancing parts which took the stock 145 hp up to 195 hp. My sister bought the Dodge Dart Swinger back in 1994 while she was in high school. She sold it in 2001. I was lucky enough to find it in February ‘23 and was able to buy it in May ‘24. I’m currently in the beginning stages of starting a full restoration on it. When I’m finished I plan on using the Royal Purple with zinc 10W-30 oil and yes, change it every 2,000 miles or once a year which ever comes first.

Before I bought my 2016 Chevy Colorado LT new in May ‘16, I had a 2002 Dodge Dakota STX with the Magnum V6. Bought that in May of 2005 with 23,000 miles on it. I sold it in May ‘16 with a little over 195,000 miles on it. From day one I used Castrol GTX 10W-30. Changing the oil every 3,000 miles As the milage got above 80,000 miles I started using Castrol GTX High Milage 10W-30 and started changing the oil every 2,000 miles. The day I sold that Dodge, the engine didn’t smoke, didn’t burn oil and didn’t leak oil.

If your getting a puff of smoke, that’s more then likely due to some oil getting past the piston rings at start up. As the engine warms up and the piston and rings expand with heat like there designed to do, the expansion is enough to keep the oil from getting past the rings. Running a thicker oil might be enough to keep the oil from getting past the rings on a cold engine start up.
 
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Before I bought my 2016 Chevy Colorado LT new in May ‘16, I had a 2002 Dodge Dakota STX with the Magnum V6. Bought that in May of 2005 with 23,000 miles on it. I sold it in May ‘16 with a little over 195,000 miles on it. From day one I used Castrol GTX 10W-30. Changing the oil every 3,000 miles As the milage got above 80,000 miles I started using Castrol GTX High Milage 10W-30 and started changing the oil every 2,000 miles. The day I sold that Dodge, the engine didn’t smoke, didn’t burn oil and didn’t leak oil.

That's a considerable waste of oil. I accomplished the same mileage and condition utilizing the factory oil life monitor with less than half the oil changes you performed (approx 30 to your 77).
 
That's a considerable waste of oil. I accomplished the same mileage and condition utilizing the factory oil life monitor with less than half the oil changes you performed (approx 30 to your 77).
Factory oil life monitor on a 2002 Dodge Dakota STX?? The only “factory oil life monitor” 2002 Dodge Dakotas came with was the milage odometer.

I’ll say it again. Motor oil is cheap engine insurance!
 
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