Buying guide
AVGAS or Jet A-1: what the fuel means when you buy a training aircraft
Published November 13, 2026.
Two training aircraft of the same size can burn completely different fuels: leaded aviation gasoline in a classic piston engine, jet fuel in a diesel piston engine. The choice affects where you can refuel, how the engine is maintained and how exposed you are to the end of leaded fuel. Below is what the official data sheets say about each engine, where the rules on leaded fuel stand in Europe and in the United States, and what to check before buying.
Which engine burns which fuel
The fuel is set by the engine on the type certificate, not by the brand of the aircraft. Some examples from the official data sheets:
| Aircraft | Engine | Fuel on the data sheet |
|---|---|---|
| Piper Seminole (PA-44-180) | Lycoming O-360 / LO-360 (petrol) | 100/100LL minimum grade aviation gasoline1 |
| Diamond DA40 D (sold as TDI) | TAE 125-01 or TAE 125-02-99 (diesel cycle) | Jet fuel; automotive diesel EN 590 only with modification MÄM 40-1292 |
| Diamond DA 50 C (sold as DA50 RG) | Continental Centurion 3.0 (diesel cycle) | Jet A-13 |
| Cessna Citation 500 | Pratt & Whitney Canada JT15D (turbofan) | Jet A, Jet A-1, Jet B, JP-4, JP-5 or JP-84 |
The data sheet for the TAE 125 engine also requires a fuel tank thermometer and a minimum starting temperature when diesel is used, because the cold-weather behaviour of diesel varies by country and season.5
Where leaded aviation gasoline stands
| European Union | United States | |
|---|---|---|
| Rule | Tetraethyl lead, the additive in leaded aviation gasoline, is on the REACH authorisation list; its uses need an authorisation | The FAA's EAGLE initiative aims to eliminate leaded aviation fuels in piston-engine aircraft by the end of 2030 |
| Latest decision | On September 8, 2025, the Commission authorised the use of tetraethyl lead in formulating aviation fuel at one refinery, with a review period until the end of April 2032 | Unleaded 100-octane fuels approved by supplemental type certificate: G100UL (2022, broad model list) and 100R (2024, Cessna 172R/S with IO-360-L2A) |
| Why | The decision found no technically feasible alternative available before the sunset date and noted the time needed to certify an unleaded substitute | A transition plan run with industry |
The European decision and the FAA page are the sources for this table.67 The FAA date is a goal, not a ban, and the European decision sets a review period, not an end date; both describe a transition already under way.
What to check before buying
- Fuel at your base. This part is our reading. Check which fuels are sold at the airfields where the aircraft will fly, and at what price, before choosing between a petrol and a diesel engine.
- On a petrol engine, the unleaded path. Ask whether the engine and airframe are covered by an approval for unleaded fuel and whether the aircraft already has the paperwork. An unleaded fuel is only legal in that aircraft with the corresponding supplemental type certificate.7
- On a diesel engine, the maintenance logic. These engines follow their own replacement or overhaul limits, published by the engine manufacturer.5 Ask for the hours left and the calendar limits of the engine and gearbox, as we explain in the DA40 guide.
- Diesel fuel in winter. If the aircraft will use automotive diesel, check that the approved modification and the fuel thermometer are installed.25
- The fuel actually used. Ask what fuel the aircraft has been flying on, and check that it matches the data sheet and any approved modifications.
Our aircraft by fuel
- Aviation gasoline: Piper Seminole, Piper Archer, Cessna 172 SP, Cessna 150 and Dornier Do 27.
- Jet fuel, diesel piston engine: Diamond DA40 TDI, DA42 and DA62 and DA50 RG.
- Jet fuel, turbine: Grand Caravan, Citation 500, Citation Bravo and Sikorsky S-76.
Sources
- EASA, type certificate data sheet IM.A.232, Piper PA-44, issue 06, Sept. 10, 2025: easa.europa.eu
- EASA, type certificate data sheet IM.A.022, Diamond DA 40, issue 24, Apr. 22, 2021: easa.europa.eu
- UK Civil Aviation Authority, type certificate data sheet UK.TC.A.00012, Diamond DA 50 C, issue 2, Sept. 28, 2022: caa.co.uk
- EASA, type certificate data sheet IM.A.207, Cessna 500, 550, S550, 560 and 560XL, issue 10, July 6, 2022: easa.europa.eu
- EASA, type certificate data sheet E.055, TAE 125 series engines, issue 16, Oct. 27, 2025: easa.europa.eu
- European Commission, implementing decision C(2025) 5923 of Sept. 8, 2025, authorisation for a use of tetraethyl lead: mase.gov.it
- FAA, Building an Unleaded Future by 2030: faa.gov