Originally Posted by j-rho

In an autocross setting, consideration of the equipment - and safety - aren't concerns the way they might be on the track. The whole "x/10ths" thing applies in a track setting as an indication of the level of risk you're willing to take in regards to your equipment and yourself. Autocross is ALWAYS run at 10/10ths.

Doesn't mean the best autocrossers can lay down perfect runs the first time. The course needs to be learned and if it's a vehicle type that autocrosser isn't accustomed to, it can take time. You can generally get a feel for the vehicle's performance envelope pretty quickly (within 1-2 runs), but to get that inch-perfect feel for where every corner is exactly, takes a little time. For some that might just be 1 run, for others it could take dozens.