Declining Fuel Efficiency Over Time?

[kerrton]

I've noticed that I got the best fuel mileage in the Rogue when it was brand new, even though I drove less efficiently to properly brake the engine in by frequently changing rpms. Lately, after 5000 km I'm noticing a steady decline in my fuel efficency, totally about 4 US mpg, for no apparent reason. I'm now only getting around mid 20's when before I reached over 30 mpg US.

Has anyone else experienced this? I always assumed that after the engine was broken in you could expect better mpg, not worse but that doesn't seem to be the case for me.

[bshess]

I have also noticed slightly decreased fuel-efficiency (less than 2 mpg, on average), but our state has implemented (since I have owned my Rogue) 10% ethanol-blend gas, so I know that does have some effect on fuel efficiency...

[ahhbeebee]

What is the total mileage on the car now? I'm seeing fairly consistent numbers. In fact, its still getting a little better. I'm just over 9100 km.

I did find that at about 6000 km or so, when I went on my first road trip there was a slight decline in the mileage (but only say 5-10% or so). But now I've been doing weekend trips for the past 2 months, its been better.

Could it be the tires? or colder temps and driving before the engine is completely warm?

[SquiggyFreud]

I have noticed it as well...about 3-4 MPG highway and 2MPG in the city,

I have 9,200 miles on the odometer.

i actually noticed this after the first oil change, which was done by the dealer. (3900mi)

[RubenTheRogue]

we got 29 mpg average just 2 weeks ago on the I90 and taconic pkwy (lots of hills)...been pretty stable since purchase...try using a different brand of gas.

[kots]

there are things to consider with your decline on MPG:temperaturetire inflation (vary with temperature)oil viscosityair filter

[jmbones]

Are you hand calculating or using the onboard computer? If using the computer, have you reset it at each fill? If not, it is averaging the mpg since the last time you reset it.

[kerrton]

I've got 6200 km on the vehicle right now, and I do all of my mileage calculations manually. Thanks everyone for the input.

[gi'me]

I've never had good gas mileage on my Rogue. My AWD typically gets 17.5 city, 24 highway. I drove round trip from Albany to Buffalo (600 miles) with just me in the car and calculated 24 mpg, i.e., fill-up divided by miles. (The on-board calculator is a joke.)

[daytrippr]

Our mileage gradually increased over the first 2,000 miles or so and has been rock solid ever since at 28 mpg (20% city, 80% highway). We are now at 9,600 miles.