5w30 conventional in push mower?

[Astro_Guy]

For the amount of oil that goes into a push mower, it seems silly to quibble over the difference in cost between a synthetic and conventional 5w30. What are we talking about here - one quart per season with some left over for topping off? Just spend the extra few $$$ for the synthetic and forget about it.

BTW - I don't know if it is appropriate to extend Briggs and Stratton oil recommendations to Honda motors. What the B&S chart does suggest to me is that a synthetic 5w40 may be the universal OPE oil for those of us who live in places where we might start a machine at or below freezing and also run it in 90 degree temperatures. Above 90 and I for one will not be mowing. It seldom reaches 100 degrees here, but I might run my generator in such temperatures. 5w40 synthetic should handle that too.

 

[NH73]

Originally Posted By: Astro_Guy


BTW - I don't know if it is appropriate to extend Briggs and Stratton oil recommendations to Honda motors. What the B&S chart does suggest to me is that a synthetic 5w40 may be the universal OPE oil for those of us who live in places where we might start a machine at or below freezing and also run it in 90 degree temperatures. Above 90 and I for one will not be mowing. It seldom reaches 100 degrees here, but I might run my generator in such temperatures. 5w40 synthetic should handle that too.
Honda recommends a 10w30, so a synthetic 5w30 would more than up to the tasked to be used in place of a conventional 10w30.

 

[Astro_Guy]

Originally Posted By: sjw91
This doesn't make sense to me. Why would it matter if the 5w30 is synthetic or not? It's still a 30 at running temperature, so it should be good up to 100 like the others.

The 5w30 conventional is likely to have a higher Noack volatility and lower HTHS viscosity. That means more evaporation loss and lower operating viscosity at air cooled OPE operating temperatures. Two oils meeting SAE 30 requirements at 100C may be very different when operating at 150C. Synthetic oils generally have an advantage at extreme temperatures, both high and low.

 

[dwendt44]

Quote:
Why would it matter if the 5w30 is synthetic or not?


Synthetic oil can take the heat of an air cooled engine better.
Oil temps can get to 250-275° is summer with extended running.


My 2¢

 

[sw91]

Originally Posted By: Astro_Guy
Originally Posted By: sjw91
This doesn't make sense to me. Why would it matter if the 5w30 is synthetic or not? It's still a 30 at running temperature, so it should be good up to 100 like the others.

The 5w30 conventional is likely to have a higher Noack volatility and lower HTHS viscosity. That means more evaporation loss and lower operating viscosity at air cooled OPE operating temperatures. Two oils meeting SAE 30 requirements at 100C may be very different when operating at 150C. Synthetic oils generally have an advantage at extreme temperatures, both high and low.


While I agree with you, I still think it's odd the conventional 10w30 is good to 100 while the 5w30 can be used to just 40.

 

[Snagglefoot]

Originally Posted By: Astro_Guy
For the amount of oil that goes into a push mower, it seems silly to quibble over the difference in cost between a synthetic and conventional 5w30. What are we talking about here - one quart per season with some left over for topping off? Just spend the extra few $$$ for the synthetic and forget about it.

BTW - I don't know if it is appropriate to extend Briggs and Stratton oil recommendations to Honda motors. What the B&S chart does suggest to me is that a synthetic 5w40 may be the universal OPE oil for those of us who live in places where we might start a machine at or below freezing and also run it in 90 degree temperatures. Above 90 and I for one will not be mowing. It seldom reaches 100 degrees here, but I might run my generator in such temperatures. 5w40 synthetic should handle that too.


Good post. May I add, if you are out mowing your lawn when the temp is 100 F send us a photo and we will send you a Bitog T shirt.

 

[Kamele0N]

 

[Audioquest]

I ran my old Honda mower with the remnants of whatever fresh oil was left over from my car oil changes. Conventional, synthetic, semi-syn, 5w30, 10w30, 5w20, you get the picture. That 1991 mower never skipped a beat and still started on the first pull when I sold it to a neighbor who still uses it to this day. I don't even know if he changes the oil in it anymore. People really overthink oil on OPE. Just keep it filled and change it regularly.