Experimental comparison of the brake performance of a spark ignition engine fuelled with gasoline and LPG.

The use of LPG as alternative fuel to gasoline is common practice in spark ignition internal combustion engines. In the past, the main reason for the use of LPG as fuel was merely due to the lower cost for the final user in comparison with gasoline. However, there are theoretical reasons to consider LPG as a very attractive fuel for internal combustion engines. Nowadays, there is a continuously increasing stock production of dual-fuel (gasoline-LPG) passenger car models. Despite of that, doubts about the real performance worsening in LPG operation still exist. The paper deals with the theoretical advantages of using LPG as fuel for spark ignition internal combustion engines. Brake performance derived from experimental analyses at the test bed of a passenger car engine fed either with gasoline and LPG are analysed and compared. The engine designed to operate with gasoline has been equipped with one of the more recent standard kit for the dual-fuel engine operation. The performance decrease in LPG operation are discussed both in steady state and transient condition.