15W-40 diesel motor oil for lawn mower

[FastGame]

Originally Posted By: OVERKILL
Originally Posted By: Eddie
If the engine has an oil pressured system it is probably OK to use but, cirtanly not the best choice. If however, it is a splash system the I definately would not use it. Ed


Why?

What makes it a poorer choice than say SAE 30, which some of those splash-lubed engines call for?

Unless you are starting at 100C, the 15w-40 is probably thinner than the SAE 30, LOL

I'm with OVERKILL on this...Why ?

For 20+ years my Wheel Horse C121 bathed in 15W-40. It's mowed countless acres of land, plowed miles and miles of snow, and the Koler that spec's 30W is still strong as ever burning no oil. Inside the engine is as clean as the day it was born...well I guess the head & piston top isn't as born date but you get the idea...

 

[Eddie]

I probably over thought this. My comment was based on the idea of what is best and not what will be OK. Ed

 

[jeepman3071]

15w40 will work perfect in a Briggs during the mowing season. With small engines, the oil level is more important than the viscosity. I have used 15w40 diesel oil many times in my own equipment as well as customer's mowers. Many customers don't check the oil in their equipment, so I use the 15w40 as a safe way to prevent failure from the machine burning oil and lowering the oil level.

Use it with confidence!

 

[Bror Jace]

Eddie, I think I know where you were going with this. With a splash lubricated engine, the dipper swings down and hits the oil resting in the sump, then splashes it about the engine.

If you use an oil that is significantly thicker than specified, it may not splash properly or in the desired pattern resulting in oil starvation.

In the same thinking, people here have speculated that when a splash lubricated engine is idling, it may be getting less-than-ideal lubrication because the dipper/splasher isn't moving fast enough to splash the oil to the places where it needs to go.

However, the differences in viscosity between straight 30 and 15W-40 are not that great. Add in a little fuel dilution and shear, and they may get even closer together. In severe high-heat conditions, I think I'd still opt for the 15W-40 ... especially if the straight 30 is a PCMO.