The more loosy version is probably better for the kind of race you described, but it gets too loose if there is nobody in front and the driver behind you is running nose to tail. I had the problem myself several times and I wasn't the only one:
I was on a public server and raced somebody who also used my setup. At the beginning I was leading, but then I got loose after a few laps, had to catch the car and he passed me. Then all I had to do was driving close to his bumper (less than a foot probably) and he couldn't hold the car on track because of the aero-loose effect.
Well, and as I don't want that to happen to me, I use a tighter version now.