My ST is 8-9months old now and just about to hit 6k miles.
Since the 1st day i had it ive felt it randomly pull on the steering wheel like the power steering was going light then getting very hvy to the left.I took it back in for the recall and told them to check this out as there was no way this was right,after 3hrs the engineer comes out and tells me that hes checked everything to do with the steering and even took it out and found nothing wrong with it.
Now a guy i work with has a ST about the same age and he says he gets this as well,what is it,does any1 else have it happening and how do i fix it

That's called tramlining, a common complaint on cars with wide low profile tyres.
It's made worse on the Fiesta because the car is narrower than say a Focus so it gets stuck in the ruts in the road caused by lorries, buses etc.
It is exagerated further on the Fiesta because the track of the front wheels is wider than the track of the rear wheels.
Make sure your tracking is always kept spot on, avoid going over speed bumps on the wrong angle,try to put just one side of the car over them at a time and keep your tyre pressures correct.
I have found that the front tyres loose pressure very quickly.

32psi (2.2 bar) front
29psi (2.0 bar) rear

My ST170 was actually worse than the Fiesta for this :|

totally didn't think this was a problem when i read the title...

lol

Afternoon,

With the huge wide 17" rims fitted, there is a higher degree of camber pull and in some instances the 16" whells fitted to the ZETEC S give better feedback through the steering.

However, they don't look as good as the 17's. Always a compromise between looks and feedback.

Chris

Mine is really bad for this, my girlfriend refuses to drive my car (bonus!!!)because it really can jerk the wheel hard to one side or the other.
I'm glad someone else is experiancing this as i thought something was seriously wrong

Yeh i have had the same problem when i first got it and noticed it very quickly. Where there are grooves in the road your tyres like to follow them and it feels like it pulls one side or the other. The low profile tyres dont help but its a common problem mate, nothing to worry about.

Ahhh great thx a lot guys you have taken a load off my mind,i thought something was wrong with it

I just hope its better than my Orion, that things was terrible for this. I never had the problem on the 15" wheels but the 17" wheels were awful!

There's a lot of road feedback through the steering wheel due to the low profiles. I had quite a surprise when I first had my ST (as I hadn't experienced driving a car with low profiles before). I learnt pretty quickly to be very careful to hold the steering wheel firm as sometimes a hole or ridge in the road can cause the steering to quicky change direction.