Bobcat S185 Oil Type: What the Skid-Steer Loader Takes
The Short Answer
The Bobcat S185 skid-steer loader uses a Kubota diesel engine. Bobcat's general recommendation for that engine is a heavy-duty diesel engine oil, usually SAE 15W-40 for typical operating temperatures. SAE 15W-40 is a viscosity grade: the oil flows like a 15-weight oil when cold and protects like a 40-weight oil when hot. Bobcat sells its own branded engine oil for this purpose. Equivalent oils that meet the API service category in the manual are also acceptable. The API category is the American Petroleum Institute's performance rating for diesel engine oils.
One point can change this answer. The S185 was built over many years, and the exact API category and viscosity chart depend on the machine's serial number and on the ambient temperature where it works. The Operation & Maintenance Manual for your specific machine is the authoritative source. The general guidance here should not replace it.
Which Oil Are You Asking About?
Owners searching for "S185 oil type" may mean any of three systems. They do not all use the same product.
System | General guidance | Note; Engine crankcase | Heavy-duty diesel engine oil, commonly SAE 15W-40 | The manual's temperature chart may call for a different viscosity in very cold or very hot climates; Hydraulic/hydrostatic system | Bobcat's specified hydraulic/hydrostatic fluid | Some manuals list an approved engine-oil alternative; confirm before substituting; Chaincase (final drive) | The fluid type listed in the manual for the chaincase | Check the manual; the chaincase is often confused with the hydraulic reservoir
Engine Oil: Viscosity and Temperature
Bobcat manuals usually include a chart that matches oil viscosity to the expected ambient temperature range. A multigrade 15W-40 covers the widest range of normal working conditions. Machines that start regularly in severe cold may need a lower cold-flow grade, such as 10W-30, if the chart allows it. Use the chart for your serial number rather than a general rule.
Hydraulic and Hydrostatic Fluid
On the S185, one fluid serves both the loader hydraulics and the hydrostatic drive. The hydraulics lift and tilt the arms, and the hydrostatic drive moves the wheels. Bobcat specifies its own fluid for this system. Some older manuals have also listed a particular engine-oil grade and API class as an acceptable substitute. Approved alternatives vary by manual edition, so check your copy before using anything other than the specified fluid. The wrong fluid can affect drive performance and component wear.
Information Not Covered Here
Fill capacities: No verified capacity figures were available for this article. Engine oil, hydraulic reservoir and chaincase volumes should come from the manual or a Bobcat dealer. Service intervals: Oil and filter change intervals are not stated here. They are listed in the manual's maintenance schedule. Exact API category: The required API service category depends on the build and engine certification. Confirm it for your serial number.
Next Step
Find the serial number on the machine's identification plate. Then check the lubrication section of the matching Operation & Maintenance Manual, or give the serial number to a Bobcat dealer. Either source will confirm the engine oil grade and API category, the hydraulic/hydrostatic fluid and the chaincase fluid, along with the capacities and service intervals for your loader.