Jeffri began his motorsport career in karting . In 2010 he switched to formula racing and drove for Eurasia Motorsport in the Pacific Formula BMW . He finished the season with 83 points in fifth place in the drivers' championship. On September 1, 2010 , Jeffri carried out an aerodynamics test for the Lotus Formula 1 racing team in the T127 on the runway of the Imperial War Museum Duxford . At 16 years and 312 days, he is the youngest test driver in Formula 1 history, replacing Nico Rosberg , who tested for Williams F1 in FW24 in 2002 at the age of 17 years and 159 days . In 2011 Jeffri started in the JK Racing Asia Series , the successor series to the Pacific Formula BMW, for Petronas Mofaz Racing . After winning the season opener, another nine podium finishes followed in the course of the year. Jeffri finished the season behind Lucas Auer and Afiq Ikhwan Yazid in third place overall. In 2012 Jeffri stayed in the JK Racing Asia Series and competed for EuroInternational . He won four races and achieved a total of eleven podium finishes. With 223 to 236 points, he was second overall behind his teammate Aston Hare .
In 2013 Jeffri and Hare stayed at EuroInternational and switched to the German Formula 3 Cup . While Hare left the series after the season opener, Jeffri drove regularly into the points. With two fifth places as the best results, he reached eighth place in the overall ranking. In addition, Jeffri took part in four races of the Formula Middle East in 2013 . He always came on the podium. In 2014 Jeffri contested his second season in the German Formula 3 Cup for Motopark . Jeffri won twice for a total of 16 podiums. With 277 to 424 points he was defeated by his team-mate Markus Pommer and finished second overall. In addition, Jeffri reached third place at the Zandvoort Masters and he entered three races in the British Formula 3 championship .
In 2015 Jeffri stayed with Motopark and switched to the European Formula 3 championship . He finished the season in 26th place overall. In 2016 Jeffri received a cockpit for the GP2 series at Arden International . A seventh place was his only point placement and at the same time his only top 10 result. He was 22nd overall. In 2017 , the GP2 series became the FIA Formula 2 championship , in which Jeffri competes for Trident .