Lol. I don't mean to be rude or anything. But seriously haha haha.
Jitna tang vitz/belta karti hai on normal petrol (87ron) i doubt koi aur garri karti hai, whereas it's only rated for 89ron.
Anyways, it would have been better if you had tried to think before posting, how can normal petrol, which is 87RON in pakistan, have a noticeable effect on a car rated at 89Ron. It won't. Atleast till 100k km. Except for a little knocking, that to near engines maximum load, which is absolutely normal. Because the power will definitely vary.
But jee plug urr gaye ya head tout gaya,that is not possible, unless he feeds the car "matti ka teel" for petrol, then i can't say.
Ab definitely un bhai sahab ki bhi garri main fault ki waja koi aur ho ge, par je, jaahil mechanic ne keh dia ke sir tussi 'high uctaanne" nai dilwaya see na is waja tou gaddi kharab ho gaye. Lo ji in bhai sahaab ne yaqeen kar lia. Cause obviously he has better things to do in life, then look into the actual cause of the fault, which his family's trust worthy mechanic or ustaad has diagnosed and managed to erase..
I respect your opinion, and no doubt toyota is the winner in car sales, and might even produce robust cars. But still coming to the mirage forum and writing the same, vitz main tou ye hai, vitz tou ye hai. It doesn't look good. This is a mirage owners and fan club. Not a vitz vs mirage ya toyota vs mitsubishi forum. So please sir is my humble request to keep it that way.
My sincere apologies if i sounded rude or offensive. I just wanted to highlight my thoughts in the friendliest manner possible 
