Maintenance and Fluid Information for 2006 GMC W5500 Forward Isuzu 4HK1
An oil change on the 2006 GMC W5500 Forward Isuzu 4HK1 starts with selecting the right lubricant. The catalog lists these engine-oil viscosity grades: 15W-40 and 5W-40. 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. The grade alone is not the whole specification, so check the manufacturer’s requirements before making your selection.
What oil weight does my 2006 GMC W5500 Forward Isuzu 4HK1 take?
The engine-oil viscosities listed for this vehicle are 15W-40, 5W-40.
How do I find the correct oil-change interval for my 2006 GMC W5500 Forward Isuzu 4HK1?
Use the manufacturer’s maintenance schedule for this engine and operating conditions. The available application data does not establish an exact oil-change interval.

