2011 Chevrolet Silverado 1500 Regular Cab Owner's Manual - Page 161

Instruments and Controls 5-17 Engine Oil Pressure Gauge Oil pressure can vary with engine speed, outside temperature and oil viscosity, but if readings are outside the normal operating range, the oil pressure light comes on. See Engine Oil Pressure Light on page 5‑31 for more information. A reading outside the normal operating range can be caused by a dangerously low oil level or some other problem causing low oil pressure. Check the vehicle's oil as soon as possible. English Metric For vehicles with an engine oil pressure gauge, it shows the engine oil pressure in kPa (kilopascals) or psi (pounds per square inch) when the engine is running.