What oil do you use in your M-18 engine?
 

After reading the thread on oil usage I did look at some straight 30wt. options. One question, is diesel rated straight 30 wt. oil any good for the Magnum?

I found some other options;
TSC 1. https://www.tractorsupply.com/tsc/pr...0-1-qt-t804860 @$4.79 per qt. (a little cheaper in 5 gallon pails) and 2. There are detergent and non detergent oils. Non detergent $9.00 @ Amazon https://www.napaonline.com/en/p/NOL75115 another @ TSC for https://www.tractorsupply.com/tsc/pr...0-1-qt-t804860
https://www.tractorsupply.com/tsc/pr...-5-qt-t1251400

Then synthetic and conventional

I don't want to write a book here, maybe you have a recommendation for the oil you put in your M-18's. Thanks, Steve

I have 3, m-18's I use detergent as the engines have oil filters, if they didn't I would use non detergent.
Detergent tends to keep particles in suspension that a filter removes
(or that is what they say anyway)
30 W dino oil is just fine.
These are not high compression or turbo/supercharged engines that would benefit from synthetics.
Kohler likes them to use 30W oil in warm temps, if one is using them to blow or push snow, that would benefit the ease of starting by using a multi-weight like 10W30.
Now if one wanted to use the most expensive oil available, no problem.
if one keeps the snow equipment in a heated building, 30W would perform just fine,
or if all one had to use was 10W30 in summer because it was all they had at that moment it would work, although they would experience increased oil consumption, and it would thin out more at the higher operating temps of the aircooled engine in warm/hot weather, so for those reasons they recommend 30W.
It is more important to change the oil regularly than anything else, along with giving the engine time to warm up before puttin' the spurs to it!:biggrin2:

I change the mower oil every spring (about 80/100 hours)
depending on the cutting season, and if I do neighbors that can't seem to keep their new junk operating.:biggrin2:
Now this is my opinion and I'm sticking to it.
Other conditions or people's wants/ needs will vary and is just fine.:beerchug:

I use either Kohler branded or Cub Cadet branded straight 30 oil. They are specifically made for small air cooled(read hot) engines. My M18's use little to no oil even after thousands of hours of usage.

I can't seem to find the 30w Kohler oil around me and the only Cub Cadet dealer doesn't have either.

I have run Rotella 15w40 with no issues.

Here is a good oil with a high zink content that the local Hustler dealer sells around me. This is what I was running in my Onan's. Amazon is too expensive.
https://www.amazon.com/Kawasaki-9996.../dp/B00HVTF7YM

25 357 02-S

https://www.ebay.com/itm/28488556084...Bk9SR6yEi8GPYQ

Thanks fellows for the great replies. I have been feeding my 3 Magnums 10w-30 most often because I had it handy. I have noticed that the main mower tractor (the one with the heaviest workload) requires frequent checks and topping off of the engine oil. I know the tractor gets real hot after mowing for an hour so, I give it time to cool off before starting back at it. When I say hot I mean you will burn your hand touching the grill shell or the front 1/3 of the hood. I don't know if that is common to the 1872 but I feel a little guilty I haven't cleaned behind the tins and wonder if clogged fins and air ways around the air cooled engine might account for the high temperatures.

All of mine have in dash oil pressure gauges added to them to ensure they have healthy pressure. You can tell when the oil gets real thin after a long hard run, the pressure will drop to 40-45, when it normally sits around 50 at full throttle.

Whatever SAE30 is on sale will work. I typically use Farm & Fleet's house brand.

I use low ash 30W from a local Case/IH/CC dealer.

Yep I agree, also Walmart brand.
Today oils are much different and better than 50-60 years ago.
We have come a long way, oil is one of the few products we can say that about, other than medical advancements.
:beerchug: