Added gearing. You have 4 gears, and a fuel gauge. Only the top gear uses fuel, the others just recover it at different rates. Your speed is affected greatly by your gears. Ultimately, gearing is an optional mechanic, it’s totally fine to just play on the default 100% speed of gear 3, but if you’re looking to get the most out of going fast, gearing and fuel mechanics are something you’ll have to learn.