Best Used Diesel Trucks Under $20K – Looking for the best used diesel trucks under $20K? You’re not alone. Diesel trucks are known for their torque, durability, and towing power, making them a favorite among tradesmen, off-roaders, and weekend warriors alike. The good news? You don’t need to break the bank to get a solid, dependable diesel truck. In this ultimate guide, we’ll explore the top models under $20,000, where to find them, and what to check before making the deal.
Why Diesel Trucks Are Worth It
Before diving into the trucks, let’s talk about why diesel is still king:
- Better Fuel Efficiency: Diesel engines deliver more miles per gallon, especially when hauling heavy loads.
- Incredible Torque: More low-end power for towing and hauling.
- Longer Engine Life: Many diesel engines easily surpass 300,000+ miles with proper care.
- Resale Value: Diesel trucks tend to hold their value longer than gas trucks.
If you need a workhorse on a budget, a used diesel truck is the way to go.
Top Used Diesel Trucks Under $20K (2025 Edition)
We’ve researched listings across Autotrader, Facebook Marketplace, Craigslist, and CarGurus to find the best diesel trucks with high reliability and performance – all under $20,000.
1. Ford F-250 Super Duty (2008–2012)
- Engine: 6.4L or 6.7L Power Stroke V8 Diesel
- Towing Capacity: Up to 16,000 lbs
- Why it’s great: Rugged frame, solid towing capability, available in 4×4
- Common Price Range: $12,000–$18,500
Pro Tip: Avoid early 6.4L models with no maintenance history. Go for 6.7L when available.
2. Dodge Ram 2500 (2006–2012)
- Engine: 5.9L or 6.7L Cummins Turbo Diesel
- Towing Capacity: 13,000–16,500 lbs
- Why it’s great: Legendary Cummins engine, minimal emissions tech on older models
- Common Price Range: $13,000–$19,500
Pro Tip: The 2006–2007 5.9L Cummins is a sweet spot—fewer emissions, more power.
3. Chevrolet Silverado 2500HD (2006–2010)
- Engine: 6.6L Duramax LBZ/LMM
- Towing Capacity: Up to 13,000 lbs
- Why it’s great: The LBZ Duramax engine is known for bulletproof reliability
- Common Price Range: $11,000–$19,000
Pro Tip: Look for LBZ engines from 2006–2007. These are highly sought-after.
4. GMC Sierra 2500HD (2006–2010)
- Engine: 6.6L Duramax V8 Diesel
- Towing Capacity: Up to 13,000 lbs
- Why it’s great: Same platform as the Silverado, but often better maintained by original owners
- Common Price Range: $12,000–$19,500
5. Ford F-350 Super Duty (2005–2010)
- Engine: 6.0L or 6.4L Power Stroke Diesel
- Towing Capacity: Up to 15,000 lbs
- Why it’s great: Heavy-duty frame, gooseneck, and 5th wheel towing
- Common Price Range: $10,000–$18,000
Pro Tip: The 6.0L has a bad rep—but if it’s been bulletproofed, it’s a solid buy.
What to Check Before You Buy a Used Diesel Truck
A good deal can turn into a money pit if you’re not careful. Here’s what to check:
Service Records
- Look for trucks with regular oil changes and documented maintenance.
Engine Health
- Watch for white smoke, hard starts, or loss of power.
- Scan for engine codes using a basic OBD-II scanner.
Transmission
- Make sure the transmission shifts smoothly.
- Heavy-duty diesels often use Allison or TorqShift transmissions – reliable but not cheap to fix.
Frame & Rust
- Check underneath the truck for frame rust, especially in northern states.
Mods & Tuning
- Avoid overly tuned or deleted trucks unless you’re ready to deal with emissions issues.
Best Places to Find Diesel Trucks Under $20K
1. Facebook Marketplace
- Local deals, easy to message sellers.
- Watch for rebuilt titles or unverified sellers.
2. Craigslist
- Great for finding private owner deals.
- Look in rural areas for trucks used on farms.
3. Autotrader & CarGurus
- Filter by price, mileage, and engine type.
- More verified listings and dealership options.
4. Government Auctions
- Check GovDeals, GSA Auctions, and local municipality auctions.
- Often well-maintained fleet trucks.
Best Diesel Truck for Your Needs
| Use Case | Top Pick | Why |
|---|---|---|
| Heavy Towing | Ford F-250 / Ram 2500 | Best torque, durable frames |
| Work & Construction Use | Chevy 2500HD / GMC Sierra 2500HD | Great balance of power & comfort |
| Daily Driver + Utility | Dodge Ram 2500 5.9L | Simple, powerful, less emissions tech |
| Off-Roading & Farm Use | Ford F-350 | Larger chassis, great for rough terrain |
Final Tips Before Buying
- Always get a pre-purchase inspection from a trusted diesel mechanic.
- Ask about past use—was it a work truck or a daily driver?
- Get a Carfax or AutoCheck report.
- Budget for future maintenance—older diesels are reliable but not maintenance-free.
Final Thoughts: Diesel Power Without Breaking the Bank
A $20K budget doesn’t mean you have to settle. With some research, patience, and careful inspection, you can find a high-quality diesel truck that’ll serve you for years to come. Whether you’re towing, hauling, or just love the roar of a diesel engine, the right truck is out there.
Quick Recap:
- Top Picks: Ford F-250, Ram 2500, Chevy 2500HD, GMC 2500HD, Ford F-350
- Where to Shop: Facebook, Craigslist, Autotrader, GovDeals
- What to Watch: Engine health, rust, transmission, service records