poor mileage... are you getting this problem too?

[Xcalibur]

Hi,

i've been really happy with my ride but not so happy with my mileage thus far. my meter reads 10.6L/100km, which is about 22mpg. this is about 30% hwy, and 70% city. still quite a bit off from what i was expecting.

in any case, i noticed something quirky, and wonder if anybody is getting this too... recently i noticed when i shifted to neurtral to coast, that my instantaneous mileage reading would be read 2.6, 3.7, 4.6, 3.8, etc... if i hit the break, then i would notice it slowly reduce to 0. likewise, i noticed when i was in "D" (automatic tranny) and it was just coasting (i.e. foot off the break), it would read numbers too. Sounds to me like i've got a sensor or programming issue...

I just brought it into service last week because i wanted to get various knick-knacks addressed (mileage issue included), but nothing showed up on their tests.

anyway, is anybody getting the same issue? or could they test this on their car and see if they are getting various mileage #s? when in theory it should read '0', as it does when the car is parked, or stopped at a light...

thanks!

 

[icyblueyez]

Have you tried calculating your mileage manually to compare? Perhaps using Fuelly as a lot of people on here do?

 

[Xcalibur]

I haven't, but my most recent mileage to kms, are about 12L/100.. it's quite a bit off from Fuelly averages...

Have you tried calculating your mileage manually to compare? Perhaps using Fuelly as a lot of people on here do?

 

[Exspeedaway]

Hi,

i've been really happy with my ride but not so happy with my mileage thus far. my meter reads 10.6L/100km, which is about 22mpg. this is about 30% hwy, and 70% city. still quite a bit off from what i was expecting.

in any case, i noticed something quirky, and wonder if anybody is getting this too... recently i noticed when i shifted to neurtral to coast, that my instantaneous mileage reading would be read 2.6, 3.7, 4.6, 3.8, etc... if i hit the break, then i would notice it slowly reduce to 0. likewise, i noticed when i was in "D" (automatic tranny) and it was just coasting (i.e. foot off the break), it would read numbers too. Sounds to me like i've got a sensor or programming issue...

I just brought it into service last week because i wanted to get various knick-knacks addressed (mileage issue included), but nothing showed up on their tests.

anyway, is anybody getting the same issue? or could they test this on their car and see if they are getting various mileage #s? when in theory it should read '0', as it does when the car is parked, or stopped at a light...

thanks!

I noticed the same thing with my CX5 and as someone explain to me when your in neutral the motor need fuel to keep on turning, when your in gear and coasting it show's zero because the drivetrain turn the motor so it doesnt need any fuel.
As for the consumption i get exactly the same thing then you, around 10.5/100km. I do 50/50 city/country road but i do really short distance, 13km to get to work. As long as the motor is not warm it's not effective as it should be. So half of my commute is on a cold engine and that's when it get the worst milleage.
I did a 450km roundtrip 2 week's ago going 115/125kmh, I average 8.2/100km hand calculated and 8.4/100km on computer after a reset. I also have a pretty lead foot coming out of a 2008 MazdaSpeed3 with roughly 300hp, that doesn't help either.
(drive2)

 

[Buger]

I would suggest to get an app to read the info from the CX-5 ECU to see what is happening. I have a CX-5 Sport with 6MT and use the android "Torque" app along with a OBD2 bluetooth adapter and can monitor all kinds of readings from the ECU. The app was about $5 and the adapter was about $15 on amazon. o2 sensor, a/f ratio, maf, throttle and timing advance readings could all be useful to see what is happening and the app can read all of these in real time and graph and log them also. The app can also check and clear any codes from the ECU.

I just got it a few days ago and have not had too much time to play with it as my wife normally uses the car. As an example though, when I'm in 6th gear with my foot not on the gas, I can see the air/fuel ratio go up to about 28:1 and the ECU reads about 255mpg (I think this is the highest ECU calculation). When I shift into neutral, I see the air/fuel ratio go back to about 14.x:1. I should put up a graph display of fuel usage per hour while doing both to compare later also. Of course the advantage of cruising in neutral at times is that you can cruise without slowing down as much due to pumping losses.

 

[Bcdad182]

Are you resetting your avg fuel economy gauge at each fill? It is very easy to get into the 10's around here, just get stuck in stop and go traffic on hwy1 or hasting street, followed by some aggressive driving (I've done it!) I've also noticed that there is a huge correlation between fuel economy and the number of traffic lights. The more lights you have to stop (and wait at) the poorer your economy will be. Still, 10 sounds a bit high unless you are heavy footed.

I've used fuelly on a previous vehicle and now on the CX5 and it helps determine if the car is lying to you. In my case I've graphed my first fills (I only have 4000KM on the car!) and undoubtedly will see a pattern start to emerge as the engine breaks in and I have more data points. I can say the the computer on the car, while not perfect does seem to consistently under-report, but not by a huge margin. Maybe add 2 or 3 points to whatever it says. I'll attach my graph, note the first fill, the CX5 reading is off as I accidentally reset it along the way so its not the whole tank. Also for the last two fills I didn't reset it either, so the CX5 reading is an average of the last two tanks instead of per tank.

I just filled up and drove 2KM home. My average economy for that trip is about 12KM/100L because its a short trip through a parking lot (lots of speed bumps) and then up a series of residential streets (all controlled with speed humps) but based on past experience it will start to come down as I put more KM's on. I hope to end up in the low 9s or high 8's. Personally I think getting 8.0 in the city (as advertised) will never happen, at least not in the BC Lower Mainland, our roads are just too congested for that!

I can't comment on why yours is appears to do funny readings, mine stays rock steady except for when I've recently reset it, which is understandable when the number of KM are low; the average moves more slowly as the km's get piled on. I've never tried coasting in Neutral as its not the best thing to do while driving, I prefer my car to stay in gear in case I need to accelerate quickly to avoid something.

Try fuelly for a few tanks, if you are still getting weird readings, then definitely take it into the dealer. You can even print the fuelly page as a record of what's happening fuel wise - it can't hurt.

 

[xtrailman]

By using a average of the 9 readings, if i have calculated correctly, the on board average reads out by 1.33 mpg.(F=9.5777 Comp=9.1666) 29.49/30.82mpg.

Which is pretty good, last time i checked using brim to brim calculations, against the on board average, the difference was about 1mpg.
That was a Audi A4, since then i never bother with the brim to brim method, just use the onboard average, and except that it might be reading out by 2mpg.

 

[Bcdad182]

My wife drove my car a couple of times and we had some snow/ice issues this week (took me an hour to go 12 KM) and now my average reading for my current tank is 10.3 L/100 Boo! Well that will kill the average. My point is, its easy to get poor mileage, but really hard to get the advertised one! Lol !

 

[MikeM.]

My wife drove my car a couple of times and we had some snow/ice issues this week (took me an hour to go 12 KM) and now my average reading for my current tank is 10.3 L/100 Boo! Well that will kill the average. My point is, its easy to get poor mileage, but really hard to get the advertised one! Lol !

In my AWD 2.0L auto transmission CX-5 I'm finding it easy to BETTER the EPA ratings of 25 city 31 hwy and 28 mpg combined. Even with extensive driving up snowy mountain passes in winter weather.

My 4000 mile mpg average is still over 31 mpg.

 

[Lando]

My mileage has been dropping since I put on the Blizzak winter tires. The average has dropped from 32.4 down to 32.2 mpg. Two of my last four fill-ups were less than 30mpg which has been a rare occurance over the past 8000 miles. I know these tires have a 1.8% longer circumference, which means I am travelling 1.8% farther than my trip odometer says, but the mileage drop seems bigger than that. I am thinking the Blizzaks must have a much higher rolling resistance, but that's a good trade off for the improved grip in the wet and icy conditions.

 

[MikeM.]

My mileage has been dropping since I put on the Blizzak winter tires.

My mpg's experienced a smaller drop when I installed Goodyear ICE snow tires at 35 psi. This morning (before I drove the car) I measured tire pressures and saw they had decreased to around 34 psi (some a little more others a little less). I had a 200 mile round trip planned on the freeway so I aired them up to 37 psi and filled the tank nearby and reset the average mpg on the trip computer. I was surprised to see the average mpg's climb to over 36 mpg by the mid-point of the trip and when I got home it was also over 36 mpg. I haven't filled the tank yet but on all previous tanks the trip computer only reads around .5 to 1 mpg high. These are the best numbers returned since the car was new and I'm not sure if the large difference is due to changing over from Shell (previous fills were Chevron) to Union 76 or the additional air in the tires.

It was 41 degrees F and trip speeds were 50-65 mph (mostly 55-60 mph).

This change in mpg's reported by the trip computer was so drastic I'm beginning to think that keeping all tires at exactly the same pressure reduces rolling resistance quite dramatically. Said another way, maybe if all tires are not the same diameter the AWD system experiences a little binding that causes drag.

 

[zoomzoom1587]

Still only averaging 24-25 mpg with the majority being highway driving. Hopefully these numbers will change after the break in period. This is with the AWD Automatic.

 

[NinjaNoises]

Still only averaging 24-25 mpg with the majority being highway driving. Hopefully these numbers will change after the break in period. This is with the AWD Automatic.

Same with me...

 

[mongo2004]

Check you tires air pressures. Bump them up to the maximum recommended by Mazda. I personally run higher though. Also, One thing that is really hurting gas mileage is that we are in winter blend on fuel. Gas mileage definitely goes down in winter