Just thinking about 2 stroke. Many people say it’s impracticle, but with direct injection and an expansion chamber, it can be more efficient than 4 stroke. Also, only a few/ at least 1 car in production has had 2 stroke. It is called the Melkus RS1000. Also, look up the VanDyne SuperTurbo. It’s exactly what it sounds like. 
Please don’t double-post, if you want your thread moved to the appropriate section, the mods would gladly oblige.
Also, there is a searchfunction on the forums. Before suggesting, search for some keywords regarding your topic. Also make sure you read the FAQ and Whats in Whats out topic the devs put up to explain what they will and will not put in the first complete version of the game.
I double posted to make sure somebody saw.
There are at least 25,216 people on the forums, and at least 50-300 of those are on the forums regularly. Someone will read your post. That is not a very good excuse to double post. Also, please use the search function next time.