Maintenance and Fluid Information for 2003 Chevrolet T6500 Isuzu 6HK1
For the 2003 Chevrolet T6500 Isuzu 6HK1, you will find 15W-40 and 5W-40 in the engine-oil listings. The matching product listings include Heavy-Duty Synthetic Diesel Oil 15W-40, Heavy-Duty Synthetic Diesel Oil 5W-40, Signature Series Max-Duty Synthetic Diesel Oil 15W-40. Those are product matches, not proof that every listed oil meets every requirement for this engine. Check the manufacturer’s oil specification before choosing one.
What oil does my 2003 Chevrolet T6500 Isuzu 6HK1 take and which oil filter is listed?
The listed engine-oil viscosity is 15W-40, 5W-40, and listed oil-filter part numbers include P559128-EA.
How often should I change the oil in my 2003 Chevrolet T6500 Isuzu 6HK1?
Use the manufacturer’s maintenance schedule for this engine and operating conditions. The available application data does not establish an exact oil-change interval.

