Eltonioni, wake turbulence is a well documented problem, if the wind is flat calm the vorticies will not dissipate easily, and flying through them isn't something to be taken lightly esp. in a light aircraft. The higher the wind and the more of a cross wind component it has, the faster the wake vorticies will dissipate; literally being 'blown' to the side.
This is where seperation of aircraft comes into play, it all depends on the weight class of your aircraft, and the weight/wake class of the aircraft in front of you.
If your flying your 172 on an ILS, to be on the safe side I'd give at least 5 to 6 mins of seperation between you and even a light jet such as Fokker 100, BAe146 or a CRJ. Maybe your AFM will give guidence on wake turbulence (as in flying behind a wake generating aircraft)
Atreyu
