Long reads are expected for this type of subject, especially when it's written by a former blogger whose patience got fed up by the mainstream excessive cliché that is plastered with pop ups and paid advertisements.
This topic is a contribution of myself to this community, the same way I share the pleasure in other forums.
I believe that you as a simple reader, owner and potential owners might come across this useful.
It came to my personal understanding (and some research thereafter) the petrol versions of Qashqai are definitely a "bit" thirsty. (glass half full)
Despite the newly developed 1.3 litre petrol engine being a lot better in terms of performance and maintenance (fingers crossed) compared to the 1.2 litre, the fuel economy seems to remain inflexible for a particular reason. I'll explain this in a bit.
I own a 1.3 litre from zero miles and I'm trying to acclimate the engine for the first thousand miles the best way I can for best results possible. I'm avoiding motorways for that matter and if possible, driving on quietest roads to go easy up to 3000 revs. We know traffic isn't particularly tolerant to snails and we don't expect them to know that you're breaking-in a new engine either.
All this with Tesco's 99RON. Personally, I've tried and tested 95RON grade fuel from Tesco, Texaco, BP and SHELL in different cars, the 99RON always gave better mileage for the price as the higher octane rating helped the engine pulling and maintaining at lower rev range.
Some might argue supermarket branded fuels. Well, I say if it's good for your mouth it must be alright for the car.
Reason why both 1.2 or 1.3 litre engines are crap on fuel it's because small turbocharged engines are in general not very fuel efficient as they rely heavily on turbo to move.
When you step on the accelerator, the turbo has to compress air to create a bang.
Since Qashqai is a big, tall and considerably heavy car to move, at "traffic acceleration and speed" let's say, the turbo has to compress more air to power the small engine. Remember, more air = more fuel for bigger bang.
If Qashqai was a naturally aspirated 1.2 or 1.3 litre engine, the economy would be greater as the air intake is limited by the size of the engine displacement regardless if you had to rev it hard to make it move. But then it would be very slow and nobody would want one, so there's a compromise.
Quite honestly, this new 1.3 litre pulls like a diesel and speeds up like a petrol. I can pull from 6th gear at 1500rpm no sweat. This is great for fuel economy.
On the other hand I envy the 1.5 diesel version fuel economy where I averaged 60/80mpg. Higher fuel energy calorie...
Couldn't justify the higher price tag for mileage and I prefer having the much better power of petrol. Again, compromises.
Unless it's a small/lightweight car, then a small turbocharged engine isn't a bad thing for fuel economy. As an example, VW UP GTi is capable of reaching close to 80mpg on extra urban conditions but with an urban consumption of under 50mpg.
Another example, I used to perform 70mpg consecutively with a naturally aspirated Citroen C1 litre engine, in urban conditions. Very light, small car, naturally aspirated engine. Being 82mpg best on extra urban conditions.
I live at the centre of a busy city mind you.
See the difference?
Therefore, the fuel economy of a small turbocharged petrol engine like Qashqai relies even more on the foot. Knowing the engine powerband is also important to whether you're going to need the turbo to kick in harder or not.
I'm nearly 700 miles in and so far my best is 48.9mpg when it was on first "half tank" and had oddly high, random tire pressure all round from the dealer. My average hovers around 35/45mpg pure city. All this following the OBC gear recommendations and coasting on gear since stopping distances are considerably short where I drive at the moment.
Tire pressure is going to be particularly important for Qashqai, especially in city since the car soaks up a lot of fuel to pull, I want to take advantage of coasting. I'm currently using 34psi front and 31psi rear for comfort as there is plenty of pot holes around here, but I virtually drive slow in centre so on the next tank I'll try on the higher manufacturer recommended tire pressure before going into extremes.
To continue
