The Jetta GLS Tdi is a turbocharged diesel vehicle that was included in the Volkswagen lineup for more than a decade. Production on this particular model was halted in 2005 as some states were tightening their air pollution rules. For example, in Massachusetts you could buy a used Jetta Tdi, while you couldn’t buy a new one due to pollution rules for new cars. The standard mpg on the Jetta GLS Tdi is 42 in the city and 49 on the highway. However, many people are looking for 2005 Jetta’s for use with biodiesel fuels and they are finding mileage in this role of 50 mpg-plus on the highway.