Free Simulation Tier Driving Games

Overview

This is a page for truly free, truly simulation tier driving games
Truly free simulation tier driving games are pretty rare, for obvious reasons. The trade-off is usually minimal content as in the case of marketing tie-ins like BMW M3 Challenge, with a single car, or Copa Petrobas de Marcas with a single series.
Inspired by jackCRATERS YouTube video 4 FREE & amazing racing games! covering Live For Speed, Copa Petrobas de Marcas, Richard Burns Rally, and RaceRoom Racing Experience

Games that are truly free, not free-to-play monetized, and have original full content (but may be limited if a marketing demo like BMW M3 Challenge).

Richard Burns Rally - Richard Burns Rally is a sim racing game, published by SCi and developed by Warthog with advice of WRC champion Richard Burns (1971–2005). It was released in 2004 for PlayStation 2 and Xbox in July, for Microsoft Windows in September, and in July 2005 for Gizmondo.
Lots of content
Still developed by modders

Copa Petrobras de Marcas - Full-fledged and free, Game Stock Car Extreme-based/rFactor-engine-based sim racing game simulating a championship experience, something like Sector 3 Studio’s RaceRoom’s DTM Experience.
Single series content

BMW M3 Challenge - BMW M3 Challenge, which is the official game to BMW´s all-new M3 Coupé, features the original high detailed BMW M3 in all its available exterior colours and the original Nurburgring GP-track in a hyper realistic racing world.
Limited content (1 car and 1 track) as it's a marketing demo

Games that are free to get into but that have a monetized model and may have limited content to start.

RaceRoom Racing Experience - RaceRoom is the premier free-to-play racing simulation on PC and home to official race series like DTM, WTCR, the WTCC and ADAC GT Masters. Enter RaceRoom and enter the world of a professional race car driver.

Live For Speed - Live for Speed is a serious racing simulator. No arcade modes, no steering aids - YOU have to do the driving.