Wider tyres improve braking but are noisier and offer less roadholding in wet conditions, according to new tests.
Germany's ADAC motoring association looked at five different Michelin tyres with rims of between 15in and 18in, all on the same Kia Cee'd.
At a speed of 62mph the wide tyres brought the car to standstill after 35.8m compared to 41m using the narrower type tyres.
When driving in wet conditions, the narrower tyres had an advantage while the wider tyres began "swimming" on a film of water at a speed of around 40mph, the testers found. The narrower tyres only reacted in a similar way at a speed of 50mph. As far as comfort and noise levels were concerned the narrower tyres also offered better qualities.
Fuel consumption increased on average by about 2% using wider tyres because of the bigger resistance surface, according to the ADAC.
Summing up the test, the ADAC said the wider rims offered improved handling but had a negative impact on comfort and economic driving. In wet conditions drivers should also adapt their speed accordingly.