iRacing's goal is not to a racing simulation video game. The developers created this software for the real racer that can gain an advantage training on virtual grounds. They created this software with the maximum amount of detail, using GPS information for tracks, and allying themselves with car manufacturers to get as much information as possible. Their aim is simple, total realism. iRacing is a subscription-based software, you pay a monthly subscription and then you can use a default setting of cars and tracks (you can buy more later according to your needs). The subscription prices go like this:
Monthly: $20, 3 Months: $50, 6 Months: $90, 12 months: $156. You need to subscribe to the website to download the game, it is just about a 169 MB download.
This is not a video game for the average Joe, the developers have allied with several top racing drivers in America to achieved full realism, and yes, you can even see some of your top stars playing online. The game obviously includes an online service were you can race against others and they even have a tournament for different levels of competitiveness.
If you have petrol in your blood vessels, then you should get a subscription.