Yes, the engines are always being pushed towards higher efficiency. They do lack any sort of innovation when compared to the KERS system, though. But the NASCAR

Yes, the engines are always being pushed towards higher efficiency. They do lack any sort of innovation when compared to the KERS system, though. But the NASCAR Cup car V8 is just an amazing piece of machinery. It operates at 7K RPM and above for extended periods of time, and until 2013, had to use a carburetor. Which is mind blowing, given the amount of issues that such fuel system would bring into such scenario.