Out of curiosity, I did a test today to look at this. I was driving a stock 330i (n2, no aids, DFP) at the Ring on both modes. I've spent ages with this car on simulation mode, and have managed an 8:28. You can feel the weight on the rear of the car as you turn into quick corners, and when you're making sudden direction changes you have to watch out for oversteer. Going into arcade mode, suddenly you don't have to be quite as careful with the back end, and the car glides along more smoothly. With a couple of laps on arcade mode, I only managed an 8:35. I think the grip and performance of the car is about the same in each mode, it's just that you're missing the finer details of car control on arcade mode. I think it's those details that I need to get the 8:28 that I got in sim mode.sumbodycoolAlso, simulation mode and arcade mode physics are slightly different. I remember "Zer0" posted a thread with a picture in regard to that.