wider tyre for bigger load (bigger car and cc), if small car using wider tyre but got lesser tork then u have prob there...

i've seen many people changing their wira rim to myvi rim, myvi rim i think not suitable for wira coz it's load, myvi are much more lighter compare to wira... even worst they still using original myvi tyre...

the merc can use low profile tyre but still comfort coz their absorber works very well even they using low profile tyre it could not disturb the comfort setup...

800 i think better, your life depend on it bro...
i will not buy cheaper tyre, if not enough just wait until then...
mine rm250 for 1 tyre, each year change 2 tyre which cost me rm500..