Best alloy wheel size

[Shilts]

I have just bought a 172, however it is fitted with aftermarket 17" alloys. Tires are all good (not all matching though) the car seems to grip the road well but I am thinking of doing a track day at mallory, so I just wanted to know what the best options are. My friend has some standard Renault alloys 15" that look like the original ones but an inch smaller, as those have very good tires on would those be better than the 17's?

Wanted to keep the spend to £150ish if possible

 

[FLOBALOB]

For track use yes 15's are better. Handles better and tyres are cheaper. 17's are just silly on a clio (IMO) , probably foul the arches. Personally its 15's only , road and track .