Piper Seneca vs Diamond DA42
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
- 111
- Median asking
- $227,990
- Range
- $89,465–$640,128
- Listed on 2+ marketplaces
- 39
- Source marketplaces
- 11
- Model years available
- 1967–2023
- 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
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) | Piper Seneca | Diamond DA42 |
|---|---|---|
| All events | 2 | 7 |
| Serious | 0 | 1 |
| Fatal | 0 | 0 |
| Fatalities | 0 | 0 |
| % Fatal | 0% | 0% |
Full Specs Comparison
| Spec / Model | Piper Seneca | Diamond DA42 |
|---|---|---|
|
|
|
| Price Range | $89,465 – $640,128 | $520,774 – $1,100,160 |
| Category | Multi Engine Piston | Multi Engine Piston |
| Model Specifications | ||
| Seats | 6 | 4 |
| Cruise Speed | 180 kts (333 km/h) | 170 kts (315 km/h) |
| Range | 750 nm (1,389 km) | 1,050 nm (1,945 km) |
| Service Ceiling | 25,000 ft (7,620 m) | 18,000 ft (5,486 m) |
| Max Gross Weight | 4,750 lbs (2,155 kg) | 3,935 lbs (1,785 kg) |
| Useful Load | 1,590 lbs (721 kg) | 940 lbs (426 kg) |
| Fuel Capacity | 123.0 gal (466 L) | 50.0 gal (189 L) |
| Fuel Burn | 22.0 GPH (83 L/h) | 12.0 GPH (45 L/h) |
| TBO | 1,800 hrs | 1,800 hrs |
| Overhaul Cost | $40,000 | $28,000 |
| Annual Fixed | $25,000 | $20,000 |
| Hourly Variable | $280 | $150 |
| Engines | 2 x Piston (Turbocharged) | 2 x Diesel |
Cost of Ownership
EstimatePiper Seneca
Diamond DA42
Which Should You Buy: Piper Seneca or Diamond DA42?
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 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.
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.
Auto-generated from current market data and published specs. Confirm with a pre-buy inspection and professional appraisal.