BYD, the world’s largest electric vehicle (EV) maker, has intensified efforts to promote its high-performance batteries and superfast charging technology around the world as it tests a car that it says boasts the world’s longest driving range in a journey from Rome to Hong Kong.A fleet of upgraded versions of the Z9GT, a car produced under BYD’s premium Denza brand, has been travelling across European countries including Italy, Croatia, Serbia and Turkey for nearly a month at the start of a 15,000km (9,315 mile) journey expected to take around 43 days, the company said.The Z9GT, fitted with BYD’s Blade Battery…