Hi @qwertypoiu thanks for your feedback.
As my knowledge is very limited as compared to you guys as i have checked on internet my engine is exactly the same as it is in the image in the link below
http://engines-toyota.ru/wp-content/uploads/2015/01/toyota-3vz-e.jpg
but still i may be wrong as i know nothing compared to you guys 
As far as your other questions its a swapped engine (from diesel) and swapped by the previous owners which i knew nothing about.
Regarding driving i try to make sure that i don't let him go above 2500 rpm, as it normally shifts gear around 2000rpm.
Regarding idling with AC is normally on traffic signals in Lahore as you know the traffic of Lahore 
On longer route the driving is majorly on the speed from 80Km/h to 110Km/h
Let me know if i can provide any other details...once again thanks for your time.