While the full version is paid, the free demo on Steam offers a deep look into engine design. You can choose different configurations (V8, Inline 4, etc.) and tune everything from the bore and stroke to the fuel system.
The base game is an older cult classic, but there is a massive community around "MWM" (Most Wanted Mod) versions and total conversions that are often shared in enthusiast circles. It features some of the most granular "part-by-part" engine building ever seen in a game. Physics-Based Sandbox Builders car-constructor-pc-game-free-download-full-version
: Indie developers rely on sales to keep updating these complex physics engines. While the full version is paid, the free