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.

Super GT announced the shift to synthetic gasoline in May 2022. The fuel in question is manufactured by ETS Racing Fuels and called Renewablaze GTA R100. The recipe hasn’t been published — which makes sense, it’s proprietary — but ETS broadly explains that Renewablaze GTA R100 is “produced from a number of different sources of sustainable biomass and consists of 100% plant-based raw materials.”

On a more pleasant note, it sounds like the drivers who participated in the test had no complaints about performance.

“The GT500 car has what you could call an ‘aggressively-designed engine’ with a lot of advanced technologies applied in it. I thought that changing the fuel used would result in some changes, but in fact the changes were so small that I wouldn’t have noticed them if I hadn’t been told about the fuel change,” noted Nissan Z driver Ronnie Quintarelli. He added that mapping-related changes were made to the car.

Super GT cars are set to switch to Renewablaze GTA R100 — which is imported to Japan for the series — in 2023.