ahmad bhai, thought of sharing my experience with you bros, this post reminded me of it. 
bhai, u mnetioned driving ur car in 5th gear at 80kph. we all often do that, cz we have in minds k "lower rpms=more economical drive".
well this is true. but driving at lower rpms like 1.5 and 2 for a long long time, we actually risk loosing our transmissions in the long run.
these rpms are good only for auto cars because an auto tranny automatically down shifts at a slope. In cvt transmissions, the story of gears is a bit different, rpms don't matter.
as for our manual cars, ur city is mashAllah new, so u'll notice in both of ur city and corolla k they even pick acceleration from 20kph in 3rd gear without any hassle, but as the car is new, we don't feel it.
transmission bears the load. one thing more that happens is that while driving in higher gears at low speeds, we often depress the pedal fully in order to get some acceleration, e.g., in an overtake. we forget to down shift.
I have experience k accelerating a car with half pedal in proper gear saves like 40% fuel as compared to if we drive in higher gear at low rpm where the engine struggles to rev up to the mark.
like, here in Islamabad, i frequently drive on gt road, u have to brake after every 200m on average, so by driving in 4th gear all the time, sometimes down shifting to 3rd when required gave me up to 40% more fuel average rather than driving in 5th all the time, and depressing full pedal occasionally for acceleration.
this also has another advantage, k if sometimes, Allah na karey, u get stuck in emergency situations, u have full control over the car.U simply depress full pedal to vrooom out of the gap, instead of changing the gear, which will cost u precious time.
I hope i made sense, cz neend boht ai hai.
