The 2010 Infiniti G37x is available as a 4-door, 5-seat sedan. Starting at $36,050, the 2010 Infiniti G37x Base (A7) Sedan is powered by a 3.7L, 6-cylinder engine mated to an automatic transmission that returns an EPA estimated 18-mpg in the city and 25-mpg on the highway. The top of the line 2010 Infiniti G37x Anniversary Edition Sedan, priced at $43,550, is powered by a 3.7L, 6-cylinder engine that returns an EPA estimated 18-mpg in the city and 25-mpg on the highway.