Hi
@Jock
I am not an expert though the tire tables are quite factual
Your 175/70 R14 are not smaller but actually 1.16% larger in circumference... relative to the tire size Audi based their homologation on, 165/65 R15
This will lead to:
Your A2 will be approx 3mm higher
Speed will be displayed 1.16% faster than reference if rpm is the same.
CV/front area value will see a very minor increase, due to the increased height of your A2
175/70 R14 will give you much increased sidewall height and this will give a softer ride.
These 175/70 R14 will in general also feels like a bit softer during curves too. (Brand/modell, load index and speed class will matter)
If you have a chance to try the rims on your A2 before you pay them, I would have tested a front wheel and checked the clearance relative to the caliper. The different rim design vary a lot so do not take the assumption that since one 14" design fit, others will too...
Arc clearance will depend on the width of your rims. The ET you mention will be ok unless rims are wider than 6.5 inch if you have standard suspension and no bodykit.
Visually, your 175/70 R14 will look like the wheel to the right... The left one is the referenced 165/65 R15 (195/55 R15 will look the same as one other example)
The best tire and rim tread I have spotted in here is:
Budget isn't really a problem. It was more to see what the difference was between the 3 different sizes? I.e. as you say, if 185/50 isn't available, then 195/50 is ok, but what are the differences? Compared to the 185/50R16 size, the 195/45R16 size has an outside diameter that is a little bit...
www.a2oc.net
I hope this can be to some help ?
Cheers
dieselfan