5w30 vs 10w30 in a Kohler V-twin ?

[Wheel]

Kohler recommends using 5w30 below 32 degrees, and 10w30 above. Wouldn't both have the same viscosity at operating temp ? Why do they not like the 5w in all temps for their v-twin ?

 

[chad8]

Because it really doesn't matter. These motors are made looser than a car engine . Thicker oil keeps them lubed slightly better in the hot weather they are likely to see. In most cases straight non-detergent 30 wt would be fine. If it was a snow blower used in winter , then I would use 5w30. Just to make it easier to start.

 

[groomerz]

Air cooled motors are looser , ie larger clearances because there operating temps vary based on ambient air temp. There concern is oil consuption when motor is started cold when piston ring gaps are big. I maint afleet of mowers in chicago with similiar kawasaki vtwins I run 5/30 in fall and spring to making starting easier in the cool mornings eventhough it is not below 32. and switch to straight 30 for summer. Oil consuption is higher with 5/30 and I expect would increase if I ran it in the summer

 

[Wheel]

So blow by and burn off come in to play more on the air cooled engines. Thanks !

 

[travlnman]

I have the 25hp Kohler in my Husqvarna mower . It gets about 30-40hrs of use a year. The first year I ran Rotella 10w30, last year I ran Delo 5w40, neither for any particular reason other than it was what I had on hand at the time. This will be the third year I have owned it..and have not added a drop of oil to it once it is full from the spring changeout. I personally think it ran best on the 10w30, and will be going that route again this year.

 

[jeepman3071]

I run 10w30 in Kohlers with the hydraulic valve lifters. They seem to run quietest on 10w30. I've tried Rotella T6 5w40, and Rotella T5 10w30, and I'm currently running Pennzoil Platinum in mine. After this change I will switch back to the Kohler 10w30 though. Their oil for whatever reason seems to run best in these Command V-Twins. I'm not one that usually buys an equipment manufacturer's own brand (I don't like the Briggs oil, way over priced) but the Kohler oil I found works best.

As far as a 5w30 versus a 10w30 I think it has to do with shear. These engines run pretty hot. 250* oil temps are normal, and some of the landscaping guys report 290* temps even with oil coolers.

 

[Bror Jace]

Don't forget that 10W-30 tends to be a bit more sheer stable than 5W-30 in higher temps. For a lawn mower run April - October, I'd pick 10W-30.