Oil grade for old Kohler

[dsmith41]

My 1980 Wheel Horse has a 14hp Kohler, model K321. I changed the oil today and put in some Pennzoil 5w30 conventional. I was reading an online manual and Kohler recommended straight SAE 30 for temperatures above 32 degrees F. It recommended using 5w30 only under freezing saying if you used the 5w30 above 32 degrees it would increase consumption and deposits.

Now I'm not really worried about, I'm not going to drain the fresh 5w30 I put in today. But after I need to change out this current fill, should I make it a point to use SAE 30 for summer temperatures? I always though straight 30 and 5w30 were the same at operating temperature, the 5w30 would just be better when it's cold.

 

[rcbc96]

Amsoil 10w30/sae30 is what I use in all my outdoor equipment.

 

[exranger06]

I use 5w-40 synthetic in my old Kohler. It's thick enough for high summer temps, it will stay relatively thin in the colder months, it's diesel rated so lots of detergency, etc. I think it's a great all-around oil for these engines.

 

[dsmith41]

I had Rotella T6 in it last summer just because I had some lying around but then this year I decided to go with 5w30 because I knew the manual recommended 30 weight. Maybe I should have stuck with the 5w-40 Rotella. But is there really that much difference between SAE 30 and 5w30 aside from cold weather properties?

 

[Astro14]

The manual for your engine was written when multi grades would shear easily and the VIs would break down quickly. Not true anymore. You're fine with what you put in....

 

[2cool]

In your climate, I'd go with any 15w40 that was available and cheap. I have run my B&S Intek for the last 4 years on it without a problem. As long as the oil has the appropriate ratings, the least cost is best. I'm guessing you have no use for a mower in late fall/winter, so low temperature operation isn't an issue. If it is, then I'd go with a 5W-40, but because it is a synthetic, it's much more expensive.

 

[dsmith41]

Winter means pushing snow. I could just run straight 30 in the summer and switch to 5w30 for winter. I don't know if it matters though, I'm probably over thinking it.

 

[jeepman3071]

Originally Posted By: dsmith41
Winter means pushing snow. I could just run straight 30 in the summer and switch to 5w30 for winter. I don't know if it matters though, I'm probably over thinking it.


I'd probably just run Rotella T6 5w40 year round then.

 

[QuietPortage]

I run T6 in all of my OPE!

 

[Sam_Julier]

I run John Deere Torq Gard 30 weight in my 1971 12 hp Kohler powered IH Cub Cadet. This oil meets the SL/CF specs and costs about $7.00/quart at the local dealer.

 

[123Saab]

I run G-Oil 10w30 in my Wheelhorse 310-8.
Kohler Magnum 10hp

No issues.

 

[JTK]

Kohler always recommended SAE30 for the K-series engines.

15w40 is an excellent choice for them too. I wouldn't run a high dollar synthetic in them given how quickly K's darken and dirty the oil. They run rich and dirty.

I never had a problem starting them in the winter with 15w40. The "15w" should start easier in the winter than an SAE30 anyway.