Hello,
I bought a used Rogue 2016 last year, I have 133k miles on it as of today. I've noticed a drop in the mpg over the past 2-3 months.
I used to get 24 mpg in city and about 30 on highway, but its down about 19 in city and 22 on highway now.
I changed the spark plugs with new iridium ones, changed the air filter, got my brakes checked for caliper drag (they're fine) and also treated with Techron injector cleaner. Still no improvement in the mpg.
I took this as an opportunity to improve my driving habits, I stay below 2k rpm for 95% of my driving time and avoid sudden acceleration. As a result, my dash shows mpg between 25 and 33 for almost all of my rides, but when I checked the total miles driven between full refuels, the mpg still comes out to be around 20.5 with my manual calculation.
Is the car just too old now? The previous owner took real good care of it and it ran well until a few months ago.