The rules for the cars are fairly open and the majority of them pertain to safety. This allows chassis builders and teams to concoct cars with lots of subtle differences between them to find a performance edge.Some offset the entire chassis to the left to reduce load on the outer tires.Speaking of tires, every driver has a different preference for how they groove their tires. Some go with simple blocks, others go for lots of grooves and sipes for more bite. Drivers try to balance grip with temperature management: more grooving creates smaller tread blocks which have less thermal mass and will overheat and chunk more quickly. More tread blocks means more biting edges and more traction.Here is a great example of the efforts teams go to for extra traction. Each corner has a different tread pattern cut into it to find maximum grip.The cars themselves are tiny. The driver sits mostly upright inside a tiny chromoly tube frame chassis with the engine partially hung off the side and partially intruding in the cockpit. This is the primary difference between micro sprints and midgets: in midgets the engine is in front of the driver and power is transmitted through a driveshaft to the rear end. In micro sprints, the engine is transverse and offset with power driven by a chain. This allows microsprints to be shorter and more compact. The minimum weight with fluids is 775 lbs.
