Super GT racers say synthetic fuel can smell weird and cause eye pain

Drivers in Japan's Super GT race series discovered less-than-desirable side-effects when testing a new type of synthetic fuel that will be rolled out starting in 2023. While the cars ran as expected, some of the pilots complained about an unexpected smell and eye irritation.

"The smell is a little strong [compared to gasoline], perhaps because the raw materials used are different. I think they are trying to mix materials extracted from various bio-based raw materials to meet high-octane standards. Some fuel manufacturers say that the smell can be changed by changing the raw material, although there's also the matter of cost control to consider," said Masahiro Saiki, the head of Honda's Super GT project, in an interview with Motorsport. He added that the fumes were likely due to the fuel not being fully burnt in the engine.

What the fumes smell like depends on who you ask. One driver told Motorsport that it's like kerosene; another compared it to a mix of gasoline and oil from a racing go-kart. Regardless, the fumes tended to enter a car's cabin when it was closely following another car.