Jet fuel is basically kerosene which is very similar to diesel.
from wikipedia:
Piston engine use
Jet fuel is very similar to diesel fuel, and in some cases may be burned in diesel engines. The possibility of environmental legislation banning the use of leaded avgas, and the lack of a replacement fuel with similar performance has left aircraft designers and pilot's organizations searching for alternative engines for use in small aircraft.[5] As a result, a few aircraft engine manufacturers, most notably Thielert, have begun offering diesel aircraft engines which run on jet fuel. This technology has potential to simplify airport logistics by reducing the number of fuel types required. Jet fuel is available in most places in the world, whereas avgas is only widely available in the few countries which have a large number of general aviation aircraft. A diesel engine may also potentially be more environmentally-friendly and fuel-efficient than an avgas engine. However, very few diesel aircraft engines have been certified by aviation authorities, and widespread use of diesel aircraft engines is still years in the future.
Jet fuel is often used in ground support vehicles at airports, instead of diesel. The United States military makes heavy use of JP-8, for instance. However, jet fuel tends to have poor lubricating ability in comparison to diesel, thereby increasing wear on fuel pumps and other related engine parts.[citation needed] Civilian vehicles tend to disallow its use, or require that an additive be mixed with the jet fuel in order to restore its lubricity. Jet fuel is also significantly more expensive than diesel, so using it in ground vehicles is considered by some to be wasteful.
Jet fuel - Wikipedia, the free encyclopedia