Super Tech 20W50 VS Diesel rated 15W40

[z71bill]

I am about to break out the pressure washer for my annual battle with sidewalk, driveway and patio mold -

Houston weather forecast 95-99 degrees for the next two weeks.

I was in Walmart and impulse purchased a quart of Super Tech 20W50 conventinal oil.

I was planning on using Chevron Delo 15W40 semi synthetic but with temps close to 100 and the 6.5 HP Kohler engine in the pressure washer running flat out for hours at a time I thought maybe the 20W50 would be a better choice.

So what is the BTOG consensus for oil under these conditions?

20W50 conventional or 15W40 semi synthetic?

BTW - Kohler recommends their 10W50 synthetic - so 50 weight is an approved oil. But for $25 a quart they can forget about that. The ST 20W50 was $4.24 a quart and I can buy 5 quarts for ~~$17.

Full disclouser - I don't recall which thread - but someplace on this forum I have stated I would never use a 50 weight oil. So maybe an old dog can learn a new trick!

 

[skyactiv]

The Kohler 10W50 is made by Amsoil and allows certain Kohler engines a 300 hour OCI. $20 at Tractor Supply Company.
Take one for the team and buy the STP straight 40W at Auto Zone and let us know how it does.

https://www.autozone.com/motor-oil-and-transmission-fluid/engine-oil/p/stp-pro-formula-conventional-engine-oil-hd-40w-1-quart/811766_0_0

 

[z71bill]

The Kohler 10W50 is made by Amsoil and allows certain Kohler engines a 300 hour OCI. $20 at Tractor Supply Company.
Take one for the team and buy the STP straight 40W at Auto Zone and let us know how it does.

https://www.autozone.com/motor-oil-and-transmission-fluid/engine-oil/p/stp-pro-formula-conventional-engine-oil-hd-40w-1-quart/811766_0_0

I can't imagine going 300 hours between oil changes on an engine without an oil filter.

 

[ArthurArgentum]

20W50 conventional or 15W40 semi synthetic?

Same song, different verse 20W-50 conv. is a good stuff.

 

[ripcord]

Coke vs Pepsi

 

[tnt_motorsports]

IMO @z71bill keep it full and find something else to worry about. Either of those oils will be fine for hours of use. I use F&F 5w40 HDEO in my OPE to aid in easier starting. Probably not a concern for you in Houston.

Just my $0.02

 

[JavierH19]

15w-40 is plenty thick for it and wouldn't really protect any more, but it has a better add pack and it's certifications means it does better drain and evaporative loss wise.

 

[DemoFly]

I don't care what the ambient temp is, I'm not running a 20w50 in splash lube.

 

[Soft Cars]

Exxon Superflo 20W-50 used to be some really nice oil for the Cadillac 425. So quiet, all you could hear was the fan belts rolling across the pulleys and the air getting sucked in through the Rochester.

 

[Slick3914]

15W-50 Mobil 1 would be ideal.

 

[z71bill]

I don't care what the ambient temp is, I'm not running a 20w50 in splash lube.

Kohler - the manufacturer of the engine has 10W50 as the #1 oil recomendation - it is full synthetic but starting the engine when it is 95 degrees outside I think 20W50 will splash around just fine.

 

[ripcord]

I've run a lot of 20w-50 through all kinds of OPE without ill effect. Some splash lubed, some not. Briggs, Kohler, Kawasaki, Wisconsin, Ford, ect

 

[RDY4WAR]

I would use Mobil 1 FS Euro 0W-40 over either of those 2. I see no reason for even the 40 grade, much less the 50 grade.

 

[DemoFly]

Kohler - the manufacturer of the engine has 10W50 as the #1 oil recomendation - it is full synthetic but starting the engine when it is 95 degrees outside I think 20W50 will splash around just fine.

Sure. Kohler recommends their expensive, high margin marketing partnership oil. But if you don't run their oil, they don't recommend anything but a 30 weight. Go ahead and run 20w50 supertech if you want.

I simply said I'd never do it.

 

[dlundblad]

View attachment 160778

Sure. Kohler recommends their expensive, high margin marketing partnership oil. But if you don't run their oil, they don't recommend anything but a 30 weight. Go ahead and run 20w50 supertech if you want.

I simply said I'd never do it.

10w50 is a thick oil for being recommended year round too. Any mowers with a Kohler engine have a similar recommendation?

Also, I have always thought too thick of oil can cause the engine to run hotter. The 300 hr OCI is quite the stretch too. Perhaps they bank on people not doing that.

 

[Lubener]

Either will be fine. I alternate between the two in my old farm tractor.

 

[Lubener]

I can't imagine going 300 hours between oil changes on an engine without an oil filter.

I agree. That's bad advice by Kohler. Atleast it will be out of warranty by then and that's all Kohler is concerned about.

 

[#18FAN]

What tip size is the majority of the cleaning done with?

 

[z71bill]

What tip size is the majority of the cleaning done with?

 

[z71bill]

I would use Mobil 1 FS Euro 0W-40 over either of those 2. I see no reason for even the 40 grade, much less the 50 grade.

You see no reason for a 40 weight oil but recommend 0W40 which is a 40 weight oil.

When it is over 90 degrees outside - I can't see any benefit of a 0W anything.