My NBFL came with 16" alloys and it tended to wander around a bit, also had a couple of sideways moments on greasy roads where the tyres (Bridgestone’s) just let go without warning. Also on some trackdays cornering was - I felt, a bit ‘iffy’ as wasn’t sure if the tyres would let go or not.
Then I read a post from a former member who also was an accident investigator, who said low profile tyres were the cause of many accidents in his opinion, as they just ‘let go’ without any warning at all. I also considered the NA was conceived with 14" wheels and after asking advice from a couple of former members who knew what they were doing, I decided to downsize to 15" wheels, adjusting the tyre sidewall accordingly.
Also, the criteria for good handling rests on unsprung weight - the wheels, tyres and brake mechanism - which latter you can’t adjust, but you can improve by using lighter wheels and tyres. The two members I had asked recommended Toyos - which are a lighter tyre, but I opted for Goodyear Eagles, which were ‘flavour of the year’ at that time (around 2003/2004)and cheaper. After three years I discovered the treads were splitting at the root of each tread, so reverted to the 16" wheels while I sorted out the problem. ( I drove more carefully on these!) I was told, by a tyre expert, that these were apparently not cured correctly, so finally went for the Toyos on the 15’s and have been happy with them ever since.
Other points you realise, tyre prices increase by wheel size, so 15’s are cheaper than 16’s and even cheaper than 17’s, which are in sensible terms just a gimmick - bought for looks and not for performance, they are also a safety issue. Footprint may seem important, but getting the unsprung weight down is the essential criteria, and maintaining the rolling diameter or the tyre, if you increase wheel size, you vary the actual road speed relative to what the speedo says. Beware speed traps! I only know of one former? member who also had a an NBFL sport who upsized to 17’s, and said they were better than the 16’s, but my own experience tells me a different story, The 15’s now give me warning when I’m pushing the grip on sharp turns, where the 16’s never did.
At the end of the day, any wheel - correctly fitted with the right tyre, looks just as good as any other size, if they fill the wheel well, but when it comes to driving, the right size and weight are more important. As Kojak used to say - “Whatever turns you on” if you just want to show off.