Nico-newbie here...
Just purchased my 1st Sentra last Friday, May 27th 2016. I got myself a used 2013 Sentra SR with about 50,000 km.
Everything was tuned up by the dealership, I am told that there is no work to be done immediately... however I am noticing very poor gas mileage according to the on-board system. When I started driving last week it was displaying 15.5L/100km. After a week of driving, about 600 km and 2 gas fill ups, and now it's showing 12.8L/100km. The mechanic told me to drive it for a bit, and said that the car had sat in the lot for about 6 months... I am hoping to see a drastic improvement, soon. On a side note, my father is driving a courtesy-car from the same dealer, it is a 2014 Sentra SV with about 10,000 km and that car is displaying 8.5L/100km when he drives it... I drove it for a day, and got it as high as 9.5L/100km, however I did do a lot of city driving during that time, while my dad does more highway driving, perhaps that can help explain the shift...
This is my newest/youngest car, so far, at just over 3 years old... and 2nd Nissan, I had an old Micra, back in the 90's the kind that you could literally lift/carry out of a snowbank if you ever got stuck... that car never gave me any trouble, but was simple as hell, no frills, no finish, no dashboard, no extras... it just got me from A to B, and it did so, slowly... I've pretty much had mostly compact or sub-compact cars, so far; 2x Ford Escorts, a Toyota Tercel, a Nissan Micra, a Dodge Neon... (maybe 1 or 2 more) plus more recently a Saturn Vue and a Honda Odyssey, an SUV and minivan, respectively.
I heard that this model of Sentra is considered to be an Altima-lite version... well, whatever the case, my wife and son love it... and so far, besides the odd mileage/full consumption, I am liking it too... I have yet to take it on a road-trip of even push it past 120km/hr... but it's only been a few days.
Thanks for reading, and for having me... I hope that I can help contribute to the site or at the very least this Nissan Sentra reliability thread.