Because some servers with the same categories of cars are different, it seems that some hold the cars, leaving no time will they lower their every turn, even when you do a perfect lap with no mistakes, a good speed, your time instead rises to download?
You go on another server in the same class of cars and can lower your time with every lap.
There should be none, I think it should be no difference between the servers, but not their cars or hold times on the track so the drivers fail to lower their times, and from what I've seen one of the best servers in time for class the GTR is Conedodgers (congratulations), only need to improve information for pilots will be signaling each turn and the track could be better, like the F1 2011.

Wut?

I believe he's talking about personal bests beeing stored on each of the servers he visits, somehow. Not sure. It can't be AIRW or LFSW, because your PBs are stored on a centralized server. Maybe he's racing on servers with some other InSim addons?

Quote from Skagen :

I believe he's talking about personal bests beeing stored on each of the servers he visits, somehow. Not sure. It can't be AIRW or LFSW, because your PBs are stored on a centralized server. Maybe he's racing on servers with some other InSim addons?

That must be it. Like Airo and LFSLapper (or whatever they're called).