New to me 1993 JD STX38 w/Kohler Command 12.5hp

[zfasts03]

Looking for oil preference for this 12.5 Kohler Command from 1993 in a John Deere 38" garden tractor.

I know that the manual calls for 10w-30 2 qts. for the temperatures of which I will be operating and a spin on filter.

I have various 10w-30's. Does this engine care? Is it okay running Amsoil ASE Small Engine 10w-30 with older material gaskets? or will this introduce leaks? or should I stick to conventional or a Group 3 based synthetic instead?

Oils on hand in order of what I think I may run: all 10w-30
1. Amsoil (ASE) small engine
2. PP
3. QSUD
4. Valvoline white bottle conventional.

I will probably run the M1-102 filter or a Wix. Maybe a Fram XG3614, not sure, but I think the gold filter w/sure grip color looks odd with the yellow and green.

Service history is sketchy. A receipt from a local lawn mower shop, 3 years ago shows a WIX filter and PennzP 10w-30. It still has an old looking Wix filter on it so I guess it hasn't been changed in 3 years. Oil looks clean and at correct level. Prior owner parted with it due to no longer using/needed it. Runs good. Tires are worn, it has some use under it's belt. Well broken in. It has the yellow deck which I hear is better? I will be going over it top to bottom as it needs belts, tires, battery, fuel line/filter, air filter, new seat, etc.

Mowed with it 2x after jump starting (due to old battery). Running good with new fuel (w/startron fuel stabilizer).

 

[Rand]

I like 15w40 in those for the hottest parts of summer but I work my older deeres for hours and hours.. oil gets pretty hot.
I dont mow below 50f typically.. maybe mow some leaves once or twice in the fall.
We have a fleet of 300 series mostly used for field and trail mowing.
One 316 got 20w50 for 20+ years and 15w40 since. its still running with 4k+ hours on it. no hour meter on that one though.
its never had rings or cylinder work done.. it did get new valves 5-8?? years ago.

I would probably use conventional. The thickness is up to you. The manual spec's a chart or at least my 200,300, and 800 series tractors do.

 

[Exit32]

I bought a John Deere STX30 lawn tractor in 1990. It has a 9-horsepower Kohler engine (same engine as the STX38, but the STX30 engine has a smaller carburetor). I use it to mow about a half-acre of lawn from April through November every year.

For about the past 20 years, I've used Rotella T6 15W-40 full-synthetic oil and Fram PH7575 oil filters. My little John Deere runs great and doesn't consume oil between annual changes. And believe it or not, that 9-horse Kohler still has its original spark plug. No need to fix what ain't broke.

 

[tnt_motorsports]

I have a 2002 LT150 with a 15HP Kohler. I bought it used in May. For the first oil change I used the Kohler 1205001 filter and M1 10w30 HM. When I changed the oil a couple weeks ago to put it away for winter I used a Motorcraft FL-400S (larger filter for more oil capacity) and SuperTech full synthetic 10W30 HM. I debated over using HDEO but wanted to stay with the high mileage oil because I think I have a small leak.

Just my $0.02

 

[dwendt44]

Fram 3614 filter will fit and work great. Cross to your favored brand if you wish.

 

[jeepman3071]

Those are excellent engines. No need to overthink it, the Valvoline conventional 10w30 and any cheap filter will work great. There is no reason to run an expensive Mobil 1 or Fram Ultra on these, even a cheap supertech filter will be identical inside to the expensive OEM Kohler filters.

 

[ripcord]

I've got tons of hours on a Command using mostly conventional10w30 and also 5w40 T6 when it was on hand. Kohler recommends 10w30 for these engines and says its because of the hydraulic lifters. I'm sure 15w40 will also work fine but if you get clatter at startup, then maybe go back to 10w30.

 

[scrowley]

My 1998 15hp Command seems to love synthetic 10w30. I think this engine is going to outlive me.

 

[Bighorn2500]

I have an old 1996 LX188 it gets 5w40 Mobil Delvac 1 or T6 and filter change yearly. It gets run year round; mowing in the summer, towing a small dump wagon, seed spreader & lawn roller occasionally. Even used it last year to tow the kids on their winter sleds through a couple of inches of snow.