Toyota testing liqud hydrogen in race car

Toyota plans to test liquid hydrogen car in 2023 endurance races - Japan Today

Toyota has already fielded a hydrogen powered ICE race car before. Now they are trying liquid hydrogen vs the highly compressed gas.

"Using hydrogen in liquid form instead of its gaseous state would double a car's mileage and allow for smaller hydrogen fueling stations."

They still see compressed gas working for commercial vehicles, but a switch to liquid for cars will mean most of the investment into current stations was a waste.

"In an endurance race last November, Toyota said it had improved the engine's output by 24 percent and its driving range by around 30 percent. It also managed to reduce cases of fire-causing abnormal combustion in the engine, with instances down more than half compared with last March."

How often were those fires to begin with?
And what about NOx emissions?