i noticed that as well but i always figured well maybe i wasnt as fast as i think i was. But if this is in fact the case than i hope updates will change that because if you are punished for beeing fast than that takes the sense out of racing.
There's been some brief mention in various threads about the so-called "online boost" which occurs during online events. This appears to be present to help keep the field from spreading out too much and also give drivers who have "offs" a chance to get back into contention.
I had posted in the Online Events thread that I felt it wasn't so much a boost to racers back in the pack, but in fact a handicap placed on drivers in the front of the field. I had the perfect chance to finally prove this out this morning.
After a few online races in the Pro Suzuka F430 event, I re-visited the Arcade to try shaving some seconds off my hot-lap time. First lap, on S3 tires, came in at a little over 2:17, and I ended the session with nearly a 2:16 flat. I then returned to the online race and ended up in a race between myself and one other driver. He ended up off the track early on the first lap, and his marker on the track map stopped moving. Apparently he'd pulled off and quit.
Perfect, now it's just me, the track, and the clock for two full laps. No drafting, no traffic. First full speed lap was a 2.24. That's almost eight full seconds slower than my best hot-lap. The final lap came in at 2:23.5, which again was way off my normal pace. My line, entries, and exits were all solid.
I finished the race, then went back to time-trialing, but this time selected S1 tires. First lap was a 2.21, still a good bit faster (and sloppier, LOL) than the best S3 lap I could manage just minutes ago during the online race. Keep in mind this was my first attempt ever with the F430 on S1 tires and it only took one lap to beat the S3 time from the online race.
So... it boils down to this:
The further ahead the leaders are in the race, the more of a penalty they receive in terms of grip and physics. Drivers in the back of the pack do not get a boost, but stay closer to the original grip/physics settings of the race.
I'm annoyed by the implementation of this practice, which seems more fit for an arcade game or at least beginner/amateur level online races. I also truly hope it does not find its way into the final GT5 package, or at the very least isn't present in "professional" setting online races.