Given a choice, more consumers indicate they would select a clean diesel engine over a hybrid electric engine to power their next vehicle, according to the JD Power and Associates Clean Diesel Market Assessment Study. According to the study, if given a choice between a traditional petrol, clean diesel or hybrid electric engine in their next vehicle, 27 percent of consumers said they would select a clean diesel, compared with 22 percent who would choose a hybrid electric engine and 51 percent who would select a gasoline-powered engine. Given a scenario where fuel prices rise above $2.50 per gallon, 56 percent of consumers said they would select a clean diesel-powered vehicle, compared with 38 percent who would purchase a hybrid electric vehicle. Clean diesel technology was defined for survey respondents as "comparable performance of that of a petrol engine, but the typical diesel noise, vibration and pollution have been reduced to that of a petrol engine." Based on that description, 22 percent of consumers say they "definitely will" consider a clean diesel engine in their next vehicle purchase and an additional 44 percent indicate they "probably will" consider a clean diesel engine. Consumers also express some con-cerns about clean diesel, including lim-ited availability of fuel and service and repair locations, along with maintenance costs and whether clean diesel engines will be available in the vehicles they desire. Vehicle manufacturers expect the first clean diesel-powered vehicles to be in-troduced in 2006, the same year the United States Environmental Protection Agency has mandated low-sulphur diesel fuel to be available nationally.