I want to get RFactor 2 but my friend said your official tracks that you sell don't have DRS zones, and when he plays against ai they open DRS even in corners all the time. Is this a bug? I don't want to buy if this is intended. Monza, Spa, Monaco, Nurburgring, Imola etc.
In practice they and you can use DRS whenever you want. In race not. Tracks have DRS zones as they do in real life.
Tracks like Spa and Monza etc that you listed have DRS zones(at least the official versions) But some cars such as the new BMW M4 uses DTM rules which allow DRS use during all parts of the track during practice and Q. The Zones are only enforced during the race itself. Other mods that simulate F1 will, if modded properly, only allow DRS at the established zones.This is the same answer I just posted elsewhere to you. Official tracks like Spa that have DRS will then have it available. Tracks like Sebring/Le Mans etc that do not allow DRS, do not have DRS rules the cars can follow, allowing DRS cars to flatten the wing whenever.
DRS works on those track - as mentioned in Practice you can use it where ever. If tracks does not have DRS zones they are not added (as mentioned by davehenrie) such as Sebring and Le Mans
Weird, he says he uses a formula 1 car, and the DRS works well with modded tracks (right zones, only with 1 second) but on these he can open it anywhere even in race. Thanks for comments, I will buy and see if I can get it working. Maybe he done something wrong.