The Bugatti Chiron Super Sport 300+ can reach up to 304 mph, but at some point even it will run out of gas. And when it does, running at 304 mph will be impossible.
That doesn’t make it any less fast of a car though. It just means that it’s low on fuel, and when it’s low on fuel it’s less likely to go very far.
Part of knowing whether or not you can win a race isn’t just based on speed or technique, but also how much resources are left in your reserve. When you’re low on fuel, performing at even 30% of your maximum can be considered a win. On those days, your 100% will be 30% of what you could give, and that might be the most you can give. That doesn’t make you less fast of a car though. It just means you might not be able to go as far as you normally could.