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Caterpillar CAT C18 ATAAC Engine

The Caterpillar CAT C18 ATAAC is a 18.13 L 6-cylinder air-to-air aftercooled engine rated at 1500 rpm. It powers generator sets from Caterpillar, including the DM9819 and DM9828. It holds 38 L (10.0 gal) of oil and 20.8 L (5.5 gal) of coolant.

Also known as: Caterpillar CAT C18 ATAAC

Part of the Caterpillar CAT engine family — 3 variants share parts & fitment.

18.13 L
Displacement
6
Cylinders
1500 rpm
Rated speed
38.0 L
Oil capacity

Engine specifications

Oil capacity38.0 L
Coolant capacity20.8 L
Displacement18.13 L
Cylinders6
AspirationAir-to-Air Aftercooled
Rated speed1500 rpm

Generator sets powered by this engine

2
Caterpillar DM9819Caterpillar DM9828

How to read your Caterpillar engine serial & model number →

Recommended fluids

FluidGradeStandardAmbientCapacityNotes
CoolantSCAC cooling / jacket waterGenerator temperature rise based on a 40 degree C ambient per NEMA MG1-32.
Engine oilLubricating oil675.0 LSump refill with filter; integral lube oil cooler, gear type lube oil pump
Fuel35 API gravityLHV of 42 780 kJ/kg (18,390 Btu/lb) at 29 C (85 F), weighing 838.9 g/liter (7.001 lbs/U.S. gal.)
FuelNo. 2 diesel fuel, 35º API gravityLHV 42 780 kJ/kg (18,390 Btu/lb)Weighing 838.9 g/liter (7.001 lbs/U.S. gal.), used at 29º C (85º F). Consult Cat dealer for Low Sulfur fuel and Biodiesel capability.

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Common questions

What is the oil capacity of the Caterpillar CAT C18 ATAAC?

The Caterpillar CAT C18 ATAAC engine has an oil capacity of 38.0 liters.

What is the displacement of the Caterpillar CAT C18 ATAAC?

The Caterpillar CAT C18 ATAAC has a displacement of 18.13 liters with 6 cylinders.

Which generators use the Caterpillar CAT C18 ATAAC engine?

The Caterpillar CAT C18 ATAAC powers 2 generator set(s), including Caterpillar DM9819, Caterpillar DM9828.