it will improve grip, but the ride will be a lot firmer because the tyres will be low profile likely 205/40/17
road noise will probably increase as well. Handling in general shouldn't really change as thats mainly too suspension but if the alloys are light they will improve handling over a heavy set i guess.
Acceleration will be effected and will be slower, top speed will slightly increase by 2-5 mph i guess and the speedo will be out by about 2-3 mph at 30mph.
I hope this is ok, just know from past experience with my old rover. Pot holes and kerbs need to be treated as a threat as denting and scraping are very easily done.
Dave
