Two cars I have had that have been transformed with smaller diameter tyres have been a Honda S600 that was very underpowered and the Nissan Silvia that was not really underpowered at all. I noticed acceleration, handling and steering felt much better. The Honda had new tyres put on by the previous owner based on price that were much higher profile than what the car had as new and the Silvia also had a shop do me a favour by fitting a size that was cheap, but cars performed badly with cheaper but larger tyres than what they were supposed to have compared to going close to factory. Every other car I have been lucky enough to buy the car with the factory sized tyres and keep to the stock size without any issues.
I always thought it was the diameter but I am now wondering if it was the weight of the larger tyres that caused the noticeably poor performance rather than the change in size.
Anyone know what load rating does to the feel of a car and any issues changing to a higher load rating? My wife's new Outlander has 255/45R20 101W tyres. I hope I will not need any for a couple of years but looking at new tyres it appears the same size but 105W is nearly half the price. All I can tell from googling 101W and 105W is 105W has a higher load rating so can carry more weight in the car without issues.
