Diamond DA42 vs Piper Seneca
The Diamond DA42 Twin Star (four-seat composite twin, Austro AE300 diesels, ~170 kt) and Piper Seneca (six-seat aluminium twin, Continental TSIO-360 piston or Lycoming, ~190 kt) are direct twin-engine competitors with very different propulsion — diesel vs Avgas.
Live Market Snapshot
Current asking-price market, aggregated across multiple marketplaces · refreshed daily
- For sale now
- 46
- Median asking
- $699,900
- Range
- $520,774–$1,100,160
- Listed on 2+ marketplaces
- 20
- Source marketplaces
- 7
- Model years available
- 2005–2026
- For sale now
- 111
- Median asking
- $227,990
- Range
- $89,465–$640,128
- Listed on 2+ marketplaces
- 39
- Source marketplaces
- 11
- Model years available
- 1967–2023
Live data from AeroGurus, aggregated daily across the used-aircraft market. Figures are current asking prices, not appraisals — confirm with a pre-buy inspection.
Safety Record
Absolute counts scale with fleet size — the most-produced types log more events without being less safe. Compare the % fatal.
| NTSB (1982–now) | Diamond DA42 | Piper Seneca |
|---|---|---|
| All events | 7 | 2 |
| Serious | 1 | 0 |
| Fatal | 0 | 0 |
| Fatalities | 0 | 0 |
| % Fatal | 0% | 0% |
Full Specs Comparison
| Spec / Model | Diamond DA42 | Piper Seneca |
|---|---|---|
|
|
|
| Price Range | $520,774 – $1,100,160 | $89,465 – $640,128 |
| Category | Multi Engine Piston | Multi Engine Piston |
| Model Specifications | ||
| Seats | 4 | 6 |
| Cruise Speed | 170 kts (315 km/h) | 180 kts (333 km/h) |
| Range | 1,050 nm (1,945 km) | 750 nm (1,389 km) |
| Service Ceiling | 18,000 ft (5,486 m) | 25,000 ft (7,620 m) |
| Max Gross Weight | 3,935 lbs (1,785 kg) | 4,750 lbs (2,155 kg) |
| Useful Load | 940 lbs (426 kg) | 1,590 lbs (721 kg) |
| Fuel Capacity | 50.0 gal (189 L) | 123.0 gal (466 L) |
| Fuel Burn | 12.0 GPH (45 L/h) | 22.0 GPH (83 L/h) |
| TBO | 1,800 hrs | 1,800 hrs |
| Overhaul Cost | $28,000 | $40,000 |
| Annual Fixed | $20,000 | $25,000 |
| Hourly Variable | $150 | $280 |
| Engines | 2 x Diesel | 2 x Piston (Turbocharged) |
Cost of Ownership
EstimateDiamond DA42
Piper Seneca
Which Should You Buy: Diamond DA42 or Piper Seneca?
Bottom line: Choose the DA42 for Jet-A diesel economics, modern composite construction and Garmin G1000 NXi — the modern training/light-twin platform. Choose the Seneca for the larger six-seat cabin, more cruise and the broader Piper support network.
Pick the DA42 if…
- Lower operating cost — ~$150/hr vs $280/hr.
- Longer range — 1050 nm vs 750 nm.
- Newer design — production from 2004 vs 1972.
Pick the Seneca if…
- Budget matters — from $89,465 vs $520,774, you save ~$431,309.
- More seats — 6 vs 4.
- Faster cruise — 180 kts vs 170 kts.
- More inventory — 107 listings vs 44.
Auto-generated from current market data and published specs. Confirm with a pre-buy inspection and professional appraisal.