Why hasn't anyone released a HD truck with a Turbo V8?

There is still lots of room for improvement in current IC engines and with hybrids, there is always the question which IC engine do you use with the hybrid system. Even with plug in hybrids, once you get past the first 50 miles not towing (probably not more than 10 miles towing any kind of load), all the energy used is coming from the vehicle's fuel tank so IC engine efficiency is still a huge factor.