A diesel generator has a much longer life span than other types of fuel (natural gas, propane or gasoline). A diesel generator will have a much lower startup and run cost as compared to natural gas. Also, maintenance for a diesel generator is substantially less than gasoline or natural gas. The safety aspect of gas generators is also a huge factor to consider. The diesel used in a diesel generator set is not flammable as it must be compressed in order to ignite. A natural gas, propane, or gasoline generator all use fuel that is flammable and explosive. Diesel Generators are much more reliable since they operate by using compression ignition and natural gas generators require spark ignition.