Just purchased a 2015 QX 60 and I am only using premium as recommended, but the MPG display on the dash is showing an average of 10.5 for mostly NYC inner city driving. Is the dash reading always accurate? Or could there be some issue with the car?

 

whoa! that's TERRIBLE mileage.


Something definitely up there. we have certainly established in other threads on here that the readout on the screen is by no means 100% accurate, though to be honest it does seem reasonably close in my opinion (may vary by up to 1 or 2 mpg). But in your case I would think it is likely off by as much a 5 or more mpg, giving it an error of about 50%. we haven't seen anyone truly report it being off by that much ever. but the screen reading takes into account time the engine is running and the car is not moving (which obviously factors into the ongoing MPG equation as 0 mpg during this time, so if you have left it running and had it parked several times for long periods of time, that could do it. I would suggest filling the tank back up to full, reset your trip mileage and also re-zero the MPG screen on the dash, run a whole tank, and then check your mileage manually. Compare that mileage to what is on your screen. Outside of variables like how many more squeezes you do on the handle of the pump, which pump or stations you go to, etc... the numbers should at least be reasonably close. If you find that your mileage calculated by hand really is even close to 10.5, there would HAVE to be something wrong unless you do leave your car parked and running for long periods of time consistently.

 

The dash MPG estimate is optimistic, actually MPG (as calculated by hand at the pump) is usually worse.

10 MPG in New York city driving may or may not be bad...it all depends. How long does it take you to drive 10.5 miles (i.e., is it ten 1.5-mile trips?) How much time is spent sitting still with the engine running? Does it take 30 minutes to go 1.5 miles because most of the time you're sitting still?

 

On this topic, just filled up this morning. Had mine in 'sport' mode and drove with no real regard for mileage (ie, somewhat crazy). screen said 19.7 mpg, hand calculations 18.25. then again, avg speed was 29 mph, so I have mostly around town/traffic driving conditions. Plus A/C running the whole time. But a LOOOOONG way off of 26 mpg, and also interesting that hand calculations varied by about 1.5 mpg this time.... interesting.... I switched to 'normal' driving mode, will check back after the next fill up or two to see what this mode produces for mpg by hand vs. the screen reading.

 

Just filled up again, made 2 decent-sized round-trips on this tank in 'normal' mode with about 85% highway. Avg speed on highway is usually about 75mph (unless you work in law enforcement, then it's 68). A/C on virtually 100% of the tank, as it is low/mid 90's here recently with HIGH humidity, so A/C is barely optional. Screen said 20.4 mpg, hand calculations showed 20.25, so relatively close between the two. This fill up was with 93 premium, will check mileage again after this tank, though this will likely be majority around-town driving, so the type of driving in that respect will not be apples to apples. But we'll see if there's ANY difference either way. My guess is no, but I'll check back in again after this tank on premium if I can remember to.

 

I just filled up again yesterday, dash reading said avg mpg was 19.9. Hand calculation was 19.6, so pretty close there. As I suspected, my mileage had gone down just slightly with more around town driving and less highway driving (my 'average' speed was only 29mph...). Either way, two takeaways for me personally. one, the dash estimated reading, at least for my vehicle and in my recent experience when I have double checked it, is acceptably close for my needs. It has pretty much always been within .3 or .4 mpg, if not closer. Two, I am not a believer in higher octane gas being of any mileage benefit, at least in my scenario with my qx60 anyway.


The last unscientific 'test' I will do here in the next tank or two, as long as I can remember, is to put the driving mode in ECO, and run a couple of tanks on premium and a couple on regular and see what the mileages look like.

 

I have never used premium. Last road trip of about 1,000 miles yielded 25 mpg with average speed of 68 mph (which means 75+ mph primarily on the highway). I do like to use eco mode with the adaptive cruise control with the eco pedal off. Otherwise keep it in normal mode and get 21-22 mpg in mixed driving.

 

good post! thx for info

 

There are huge difference on my qX60. I believe the dealer filled in regular. The fuel efficiency was compromised significantly. I was about to complain then I filled in premium. Beautiful. The engine was designed for the premium which I can tell.

 

Anyone with the 2025 using regular? It now says that it is required rather than recommended as of 2025 model. I asked the dealership if it was really required and was told it was recommended and that some of their clients with 2025's are using regular.

 

... is required rather than recommended as of 2025 model. I asked the dealership if it was really required and was told it was recommended and that some of their clients with 2025's are using regular.

I've quoted the manual below. Basically the smaller engine needs higher octane to better control ignition (via octane). In general, you should stick with premium. When regular isn't available, avoid goosing the throttle.

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Here (page 584) is what the manual states:

FUEL RECOMMENDATION
Use unleaded premium gasoline with an octane rating of at least 91 AKI (Anti-Knock Index) number (Research octane number 96). If unleaded premium gasoline is not available, unleaded regular gasoline with an octane rating of at least 87 AKI number (Research octane number 91) may be temporarily used, but only under the following precautions:
• Have the fuel tank filled only partially with unleaded regular gasoline, and fill up with unleaded premium gasoline as soon as possible.
• Avoid full throttle driving and abrupt acceleration.