Hi Pete,
Me either, but I've done it to most small cars I've owned.
1. Generally larger tyres have a wider tread, & therefore more contact/grip/traction with the road ?
2. Generally larger tyres are greater in diameter, so slightly less revs required to cruise at the same speed ?
3. Generally larger tyres produce a greater track width, with better & safer handling ?
4. Generally larger tyres on small cars, results in lower weight on the tread, & less wear/longer life ?
5. Generally larger tyres create a more pleasant looking vehicle ?
Take this late 1950s early 1960s Ford Anglia 105E Piddly little 510 x 13 inch wheels. I've seen wheels bigger than that, on a wheel barrow.
I know, because I used to own one once. I put 640 x 14 Holden wheels on it, & the 640 x 14 Holden tyres were cheaper than I could buy the 510 x 13 tyres.
Lower it a bit, & then the car became a different animal. Green one looks scared . . . . . . The Red one looks like it could take on anything.
Mind you, if that's not to your liking, you could make the wheels & tyres just a little bit bigger.
Cheers Banjo