Bro, let me tell u straight... Alza.... pls dun too low .. will not bring u comfort as it tend to be more bounce on those uneven road due to low profile. So , 195/50r15 is not recommended at all.

I assume u get Alza because of family use as well, so opt for those that give u better comfort on road.

195/55r15 is acceptable with better handling in road.

no need to go for 195/60R15.. too big. When u upsize, certainly it won't be as fuel saving as before, but depending on ur requirement lor~