Was keenly reading of Iran and its use of CNG cars ;
https://www.ft.com/content/ad19885c-58bd-11e2-99e6-00144feab49a
Was also reading that the longest range CNG cars were German based:
1. SEAT León TGI:
• Total Range: Approximately 440-500 kilometers on CNG.
• Mileage: Around 28-32...