Workhorse chassis are widely used in motorhomes, delivery vans, and commercial vehicles across North America. These vehicles are powered by robust gasoline or diesel engines, requiring consistent maintenance, including regular oil changes.
To help owners and mechanics service these vehicles accurately, we’ve compiled an updated engine oil capacity chart for all common Workhorse chassis models. This guide includes model names, production years, engine types, oil capacity, and recommended viscosity, all in a simplified format.
Workhorse Engine Oil Capacity Chart
| Chassis / Model | Year Range | Engine Type | Oil Capacity (with filter) | Recommended Oil Viscosity |
|---|---|---|---|---|
| W20 | 2001–2010 | 8.1L Vortec V8 (Gas) | 6.5 qt | 10W-30 / 15W-40 |
| W22 | 2001–2010 | 8.1L Vortec V8 (Gas) | 6.5 qt | 10W-30 / 15W-40 |
| W24 | 2003–2010 | 8.1L Vortec V8 (Gas) | 6.5 qt | 10W-30 / 15W-40 |
| W42 | 2005–2011 | 6.0L Vortec V8 (Gas) | 6.0 qt | 5W-30 / 10W-30 |
| W62 | 2007–2012 | 6.0L Vortec V8 (Gas) | 6.0 qt | 5W-30 / 10W-30 |
| R26 (UFO) | 2007–2009 | 8.1L Vortec V8 (Gas, Rear Engine) | 6.5 qt | 10W-30 / 15W-40 |
| R32 | 2007–2010 | 6.5L Detroit Diesel V8 (Turbo Diesel) | 6.5 qt | 15W-40 |
| P32 (Motorhome) | 1999–2005 | 7.4L / 8.1L V8 (Gas) | 6.5 qt | 10W-30 / 15W-40 |
| P42 (Step Van) | 1999–2004 | 6.5L Diesel V8 or 5.7L Gas V8 | 5.0–6.5 qt | 10W-30 / 15W-40 |
| W88 (Motorhome) | 2003–2009 | 8.1L Vortec V8 (Gas) | 6.5 qt | 10W-30 / 15W-40 |
| W18 | 2000–2005 | 7.4L V8 (Gas) | 6.5 qt | 10W-30 |
| W56 (Electric) | 2022–2025 | Electric Motor (No engine oil) | N/A | N/A |
| W22D | 2005–2008 | 6.6L Duramax V8 (Diesel) | 10 qt | 15W-40 |
| W40 (Van Chassis) | 2002–2007 | 6.0L V8 (Gas) | 6.0 qt | 5W-30 / 10W-30 |
| LCF Diesel (W5500) | 2004–2009 | 5.2L Isuzu I4 (Diesel) | 10.5 qt | 15W-40 |
| W16 | 2001–2005 | 7.4L Vortec V8 (Gas) | 6.0 qt | 10W-30 |
| W25 | 2006–2010 | 8.1L Vortec V8 (Gas) | 6.5 qt | 10W-30 / 15W-40 |
| W44 | 2007–2012 | 6.0L Vortec V8 (Gas) | 6.0 qt | 5W-30 / 10W-30 |
| P30 | 1999–2005 | 7.4L Vortec V8 (Gas) | 6.0 qt | 10W-30 / 15W-40 |
| LF72 (Commercial) | 2005–2009 | 6.0L Vortec V8 (Gas) | 6.0 qt | 5W-30 / 10W-30 |
| W52 | 2010–2015 | 6.0L Vortec V8 (Gas) | 6.0 qt | 5W-30 / 10W-30 |
| W64 | 2013–2018 | 6.0L Vortec V8 (Gas) | 6.0 qt | 5W-30 / 10W-30 |
| W7500 (LCF Diesel) | 2004–2010 | 5.2L Isuzu I4 (Diesel) | 10.5 qt | 15W-40 |
| W34 | 2012–2016 | 6.0L Vortec V8 (Gas) | 6.0 qt | 5W-30 / 10W-30 |
| W56D (Diesel) | 2015–2020 | 6.6L Duramax V8 (Diesel) | 10 qt | 15W-40 |
| W64E (Electric) | 2023–2025 | Electric Motor (No engine oil) | N/A | N/A |
| W46 | 2017–2022 | 6.0L Vortec V8 (Gas) | 6.0 qt | 5W-30 / 10W-30 |
| W8500 (LCF Diesel) | 2006–2012 | 5.2L Isuzu I4 (Diesel) | 10.5 qt | 15W-40 |
Note: Oil capacities and viscosities may vary slightly based on specific configurations or model years. Always consult the vehicle’s owner’s manual for precise specifications.
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Key Maintenance Tips
1. Check Your VIN for Model Identification
Workhorse VINs typically start with “5B4” and contain the model info. For example:
- W22 and W24 = Motorhome gas chassis
- R26 = Rear-engine gas motorhome
- W42/W62 = Step vans
- W56 = Electric step van
This info helps you determine the correct oil capacity and viscosity.
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2. Oil Viscosity Selection
Use 10W-30 in most climates. Switch to 15W-40 for high-temperature or heavy-load operations. For newer or lower mileage engines, synthetic 5W-30 can offer better cold start performance.
3. Diesel vs. Gasoline
Diesel engines (like the 6.5L Detroit Diesel or 6.6L Duramax) often require higher oil volumes and heavy-duty engine oils. Gasoline engines like the 8.1L Vortec typically hold 6.5 quarts and operate well on conventional or synthetic blends.
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4. Electric Models
The W56 electric chassis has no internal combustion engine, so it requires no engine oil. However, service intervals still include gearbox or drive unit fluid checks.
Oil Change Recommendations
- Change interval (Gas): Every 5,000 miles or 6 months
- Change interval (Diesel): Every 7,500 miles or as per the engine manual
- Filter replacement: With every oil change
- Pre-fill oil filter: Helps prevent dry starts on large V8 engines
Always warm up the engine before draining the oil to ensure a full flush. After filling, run the engine briefly, wait a minute, then check the dipstick for proper level.
