i feel that diesel vehicles do not stall much and can be driven in lower gears in traffic laden roads so not much of gear shifting needed. Another advantage is the higher torque helps you in climbing hilly roads with ease.
^^ I too thought like that till i driven a punto daily in traffic. I thought it is a diesel car is good to drive in city, but now i like my petrol esteem in city and i love to drive my brother's city zx.
I own a M Esteem(1300 CC, 85 BHP) and using it mainly on weekends and sometimes to office, I daily drives my collegues Punto diesel(1250 CC, 74 BHP) to office(60KM) for the past 2 months.
The difference i felt,
Esteem had tall gears and in slow moving traffic /blocks/bad roads, i had to drive in 1st gear (need to downshift to 1st in advance)most of the time and need to use the clutch. It wil sudden catch speed in 1st or 2nd gear itself and easily move as per the tarffic speed without much hard accelertaion. But it will be difficult to use 4th & 5th gear in city under 60km/hr speed with AC and load.
In Punto, due to the small gear ratios, we cant catch up speed according to traffic starting to move unless we are giving hard acceleration and the vehicles behind us will start to honk. Engine got stalled when i tried to move in 2nd gear in a bad road or a slight incline with 2 people including me and AC. But with full load and Ac, we can drive this car in 4th/5th gear easily at 40-60km/hr speed. We dont have to down shift punto like esteem in 3/4/5 th gears. Also speed not reducing even we didnt given accelerator input in top gears like petrol.
From my experiance, more than petrol/diesel, it is the engine size/ weight of the vehicle matters . It is very comfortable to drive a diesel manza, honda city petrol, innova in city/highway with load, but it is difficult to drive an alto,zen, wagon r with load in city/highway.