What is the Detroit DD8?
Detroit’s DD8 is a 7.7 L medium-duty diesel engine. It occupies a different place in the range from the four-cylinder DD5 and the heavy-duty DD13. Identify the truck-specific rating and generation before using a specification found in a general product comparison.
What matters in a comparison
For a DD8-powered work truck, describe the route and installed body as well as the required load. Compare the completed truck with a DD5 alternative only if both can meet the same approved requirements. Consider engine hours, auxiliary work and service access in the cost estimate. Keep a maintenance allowance distinct from actual cash already spent on repairs.
Fluids & filters
GHG17 DD8 medium-duty engine.
Reference checked:
Identify the unit first
Use these details to match the manufacturer's application record before choosing a fluid or ordering a filter.
- Truck VIN
- Engine model and serial number
- Engine emissions/model year
- Installed filter-housing model and original part number
- Factory coolant label and subsequent coolant-change records
- Detroit generation/control-system designation
- Fuel processor model (for example, Davco Diesel Pro 245)
Fluid specifications
Engine oil
Detroit DFS 93K222 (API CK-4) or DFS 93K223 (API FA-4), using an approved product and the prescribed viscosity.
GHG17 DD8.
Source 1 ↗Engine coolant
Detroit DFS 93K217-approved coolant matching factory chemistry: Power Cool Plus for OAT extended-life fill, or Power Cool for conventional SLC fill.
Identify the factory ELC/SLC fill first; approval alone does not justify mixing coolant types. Freightliner EconicSD DD8 uses SiOAT factory coolant and needs its specific approved product.
Source 1 ↗Filter numbers & cross-references
A catalogue cross-reference links part numbers. It does not confirm that either part fits every version of this model. Match the original part to the unit first, then check the replacement manufacturer's application and any supersession.
Fuel/water separator — Davco Diesel Pro 245 only
First identify this exact original part through the OEM lookup for your engine serial number and VIN. Baldwin’s guide associates this pair with DD5/DD8 using a Davco Diesel Pro 245, 10-micron arrangement. Other Davco housings are not covered. The catalogue cross-reference alone does not confirm fitment on every engine in this family.
Application not established by this cross-reference. Confirm this original part number in the manufacturer’s parts catalogue for the exact model and serial number before considering an alternate.
Source 1 ↗Manufacturer catalogue cross-references
- Baldwin PF46171Check catalogue ↗
- Fleetguard FS20081Check catalogue ↗
Detroit Genuine Parts — dealer/Excelerator lookup ↗
Detroit approved lubricants and coolants ↗
What still needs unit-specific confirmation
- Confirm current part supersessions and vehicle-specific fitment through the OEM before ordering. Quantities, capacities and maintenance intervals require the serial-specific manual.
- An application-confirmed DD8 engine-oil filter number was not established in the reviewed primary sources; use the serial-specific Detroit lookup.
Official service and parts references
Source 1 ↗ Source 2 ↗ Source 3 ↗ Source 4 ↗ Source 5 ↗Follow the current manufacturer's manual for the identified unit. This page does not set a drain interval, fill quantity or repair procedure.
Questions to take to the supplier
- What exact rating and year-specific specification apply?
- How does the body use auxiliary power?
- What usage and maintenance history is documented?
Sources & limits
Manufacturer material supports the identification and overview above. Comparison considerations and supplier questions are Truck University’s original editorial interpretation, prepared with AI assistance. They are not an independent performance test or expert inspection.
Model-family reference only. Availability, specifications and service requirements can differ by year, market and configuration. Verify the actual vehicle or component using its identification and current manufacturer documentation. Do not use this page as a parts-fitment, modification, repair or loading instruction.
Published specifications and examples retain their labelled units; the header preferences apply to calculators.
Read our editorial method