MARAD study shows renewable diesel fuel reduces emissions without impacting engine performance. The Maritime Administration (MARAD) has recently completed tests of renewable biofuel technology onboard the training ship State of Michigan. The project was part of a MARAD initiative to conduct “at sea” tests of advanced renewable fuels and assess its impact on the ship’s engine. The tests compared operational, vibration and air emission differences between regular ultralow sulfur diesel (ULSD) fuel and a 76/33 blend of ULSD and Amyris Renewable Diesel (ARD) fuel, which is derived from sugar.