About that time to put in fresh oil for the season. I have a zero turn with a Kawasaki FS651V that I currently run KTech 10w-40 until my warranty is up. I inherited an older John Deere GX85 with a B&S. It has sat for many years. I am going to freshen it up to use and was curious what people thought would be a good oil to run. B&S states a synthetic 5w-30 is best (https://www.briggsandstratton.com/en-us/support/faqs/mower-oil-type-and-capacity). I was thinking a 10w-30 synthetic would be better in my area due to the high temps. I run mowers in the spring, summer, and fall. The ambient temp range during those seasons is from 40s to 115 heat index. I was looking at amsoil 4 cycle oil for the John Deere and will possibly put the zero turn on that once the warranty ends. Thoughts on just running AMSOIL Signature Series 5w30? Mobil 1? I don't mind having separate oils for different applications but also won't turn down being able to use same oils across different applications to save myself some money.
Mower oil recommendations
- Thread starter lgndryhr
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The cheapest 10w30 will be fine 
Dollar Tree used to sell a 16 oz bottle for $1, but they don't have that anymore
If you're changing the oil on a car and have some left over, use that. If you can find clearance oil, that is good too. OPE lawn mower engines aren't picky.
Dollar Tree used to sell a 16 oz bottle for $1, but they don't have that anymore
If you're changing the oil on a car and have some left over, use that. If you can find clearance oil, that is good too. OPE lawn mower engines aren't picky.
Use whatever 30 or higher weight oil you have left over from what you use in your vehicles. Clean and full is the most important thing.
I'd go 40wt. The fr651v runs great on heavier oil. I have that engine in my zero turn , 2013 model, 250 hours or so.
I use Amsoil synthetic 15w40 AME oil. High TBN.
https://amsoilcontent.com/ams/lit/databulletins/g473.pdf
I use Amsoil synthetic 15w40 AME oil. High TBN.
https://amsoilcontent.com/ams/lit/databulletins/g473.pdf
A heat index of 115 is WAY too hot to run those poor machines. For their sake you need to keep them in the shade and drink cold beverages when it's that hot, lol.
I vote Super Tech Full Syn 15w40 HDEO. I feel like you'd be better off running a cheap oil and changing more often in those temperatures. I am keeping my grandparents fleet of MTD made mowers alive on it and Supertech filters. She mows around 5-7 acres a week with residential mowers.
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Like some 15w40 HDEO for the air cooled machines. They get hot and most of their duty is performed in the summer. I run Traveller from TSC at the moment, got a good deal on 5 gallons a while back.
I run HPL 10w-20, because it was built to run through Death Valley on a plus 100 degree day, and because I have some.
Mobil 1 15W-50 for an air cooled engine at that heat level.
I use SuperTech 10w-40 Blend in all my Out Door Power equipment.
Valvoline High Mileage Synthetic 10w-30 is running smooth in my Honda 216.
Mowers and snowblowers have what ever oil I have for the cars, so NOW I have Valvoline Restore and Protect 5w-30, Mobil 1 ESP 0w30, and Valvoline Euro 5w-40. Last year it was Motul 8100-Clean 5w-40 Gen 2.
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I'm running HPL 15w-40 in mine.
+1 - I kind of assume most lawn mower engines have grass clippings stuck in the cooling fins and run hot. So when I order Amsoil ATF and gear oils I also order a couple of QTs of Amsoil synthetic small engine oil.
Tried to limit the variety of oils I keep at home, now down to three. For the lawnmowers and my air-cooled Triumph Thruxton twin I use Mobil 1 Full Synthetic 15W50. Seem to be working well in all applications, no issues as far as I can tell and on inspection engines are clean. Can reach 90's in Michigan during occasional summer days, so in my mind the 50 is a good choice and widely available during the warmer season for air-cooled engines.
Amsoil is great but I would say it's overkill for this type of application. You should be changing the engine oil at least once per season and unless you're doing commercial work you're probably not putting enough hours on the machine to use up a long-life engine oil.
I would look for a quality 40 grade engine oil like a 5w40 - 15w40. The Kawasaki is pressure lubricated with a filter and probably has 4x the running hours between changes compared to the flat-head B&S.
How many hours do you expect to run on each machine per season?
I would look for a quality 40 grade engine oil like a 5w40 - 15w40. The Kawasaki is pressure lubricated with a filter and probably has 4x the running hours between changes compared to the flat-head B&S.
How many hours do you expect to run on each machine per season?
