I am think about getting these http://www.ebay.co.uk/itm/New-Genuine-Ford-Fiesta-17-5-spoke-Alloy-Wheel-2008-onwards-MK7-FROZEN-WHITE-/160798556373?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item25705740d5

What would be issues from going from 15" to 17" ? if any.

what are the ford standard tyres that go on these wheels,

Fiesta's are fitted with 17' alloys so there shouldnt be a problem with fitment. The only thing that changes when going from a 15' to a 17' is the tire wall size. So I assume you will be going from a 50 side wall to a 40. This will also mean a firmer ride than on your 15's - I prefer the firmer ride but that is all personal preference

The increase in alloy size and decrease in side wall try to minimise the difference in circumference but there will always be a bit which means on the 17's you will have less of a speedo error. To work out your new speedo error use a website like this,

http://www.1010tires.com/Tools/Tire-Size-Calculator

Ive read that you should aim for no more than 4% difference because then you are likely to get caught on speed cameras and the like.

Good luck with the new alloys - I like the white!

Thanks

Not sure why but I have a steering rack limiter fitted along with the optional 17" alloys from ford on my mk7.5, the tire size is 205/40/17, weather you'll need one if you go up to 17"s I couldn't say.

You don't need the limiter if it's oem 17" ET47,5. But my dealer told me it's needed if I lower it