What are the pros and cons?
Would my geo settings get messed up because of it?
Prices are cheaper due to size being more popular but tyre prices do fluctuate, I don't have that size personally, I have a wider wheel than stock so fit an even bigger tyre 235/40/17
Negligible impact to performance and handling but if I was to list
Cons, not even worth listing really:
Increase in gearing by 1.5% so less margin on speedo and theoretically impacting acceleration (good luck feeling that )
Tyre will be heavier because it is bigger, again hard to notice such is eh variance between brands of same size you’d unlikely notice, it would be less than a switch to a track tyre, as an example I used CSC5 and switched to AD08R in the same size, that tyre was 2.5kg heavier than CSC5 per tyre. this minor size increase you are looking at is likely to be under 0.5kg.
Pros
Generally better price 10-15quid a tyre
More rubber choice in the size due to its popularity though there are good tyres in mk3 OE size.
More rubber on the road, generally offers more grip, particularly when the car is not actually that light.
Geo won’t be affected so minimal is the difference between sizes