2021 CX-5 GT FWD with Low MPG

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MAZDA CX-5 Touring
Hello guys, I just got a 2021 CX-5 GT FWD and love it. Not my first CX-5 and I was getting nearly 31 MPG on my last one. Now, same driving I'm only getting about 26 MPG, Hwy and in the city I've seen even lower numbers 18-20. No bumper to bumper driving and I babied my vehicles.

I've seen some drivers here with low numbers on their CX-5 having poor fuel efficiency (Carbon Clogged Intake Valves).

My 2021 only had 7 miles when I bought it but was sitting in the lot since December.

Question, do you guys think that because the vehicle has been sitting for that long, it explains the low MPG? What should I do, floor it on the Hwy, run the tank empty so I can get rid of that gas that might be old?
 
I have exactly the same CX-5 as you. It was manufactured in Nov. 2020. I purchased it with 3 miles on the odometer in late Jan. 2021. It now has 2052 miles.

The trip computer says it has gotten 26.6 mpg over those 2052 miles. When I calculate it’s mpg over those same miles, it’s getting 25.4 mpg, so the car’s computer is off by 1.2 mpg. I live in Illinois, so flat terrain. I drive my car very easy. I’ve only floored it once or twice since I test drove at the time of purchase (why I don’t need the turbo version). My mix of driving is about 60% highway and 40% city, with no bumper-to-bumper driving.

According to Fuelly.com, the mpg average for all 2020 GT models was 25.6 mpg over the course of 57,870 miles. The average for all 2021 GT models was 24.2 mpg over the course of 7097 miles.

So it looks like the mpg you are getting is comparable to my car and a bit better than the averages reported on Fuelly.com. Like you, I was hoping my CX-5 would do better mpg-wise, but it is what it is. I doubt it will improve much, unless I take it on a long trip where the mpg will certainly increase.

I would highly doubt your car’s sitting on the new car lot for a few months has anything to do with its gas mileage. Same with the gas that’s in it. The gas mileage may improve a bit as it gets broken in, but mine didn’t. I wouldn’t expect more than 1-2 mpg improvement, if that.

You didn’t state how many miles your car has, nor if the mpg you are seeing is based on the car’s total miles, last tank, instant readout, whether you did the math to get the mpg or if you are reporting it’s mpg from the car‘s computer. Plus, your mileage calculations can vary by 3-4 mpg based on how full you get the tank. There are many, many variables. Until you can get a calculated mpg average over a few thousand miles, I wouldn’t get too excited that it now appears to just be getting 26 mpg. That’s far better than the 14-15 mpg I was getting on my old Tahoe. It’s not that far off from the 28-30 mpg I’m getting on my 2009 Honda Civic with 140,000 that I’ve owned since new and drive like the old man that I am.
 
@P-51 Lover I have less than 500 miles so I think it'll be fair to drive a couple hundred more miles to get a better fuel efficiency reading.

And yes, I do have a hitch installed but the Rav4 I traded in had one too. The Rav4 had a horrible aerodynamics underneath, specially near the hitch and rear bumper.
The MPG on the Rav4 didn't change much with the hitchinstalled.
I drive solo most of the time.

Again, I gotta give it a couple hundred more miles and see if it gets better. And like I mentioned before my prior CX5 was getting about 30 MPG on a Hwy (70-75 MPH).
 
⋯ Again, I gotta give it a couple hundred more miles and see if it gets better. And like I mentioned before my prior CX5 was getting about 30 MPG on a Hwy (70-75 MPH).
I’d agree with @P-51 Lover that it is what it is and I doubt the gas mileage will improve much on your new 2021 CX-5 GT FWD even after the break-in period like many have believed.
 
Let the engine break in a bit more. Too, how is the OP “calculating” the mpg? Is he using the values shown on the trip computer - or hand calculated? If the former forget it, different brands/years may use different calculations for mpg. If the OP actually cares about his mpg he will hand calculate it over at least 1000 miles. Anything else is just BS.
 
Hello guys, I just got a 2021 CX-5 GT FWD and love it. Not my first CX-5 and I was getting nearly 31 MPG on my last one. Now, same driving I'm only getting about 26 MPG, Hwy and in the city I've seen even lower numbers 18-20. No bumper to bumper driving and I babied my vehicles.

I've seen some drivers here with low numbers on their CX-5 having poor fuel efficiency (Carbon Clogged Intake Valves).

My 2021 only had 7 miles when I bought it but was sitting in the lot since December.

Question, do you guys think that because the vehicle has been sitting for that long, it explains the low MPG? What should I do, floor it on the Hwy, run the tank empty so I can get rid of that gas that might be old?
Here's my comparison in a 2020 Touring, essentially the same vehicle for these purposes, except I have AWD.

26 highway and city is plausible depending how much city and what kind of city is mixed in. At an extreme, driving in Manhattan where the numbered streets average about 1/20 of a mile apart and the Avenues average about 1/7 mile apart I wouldn't expect to get out of the teens, maybe mid-teens.

I can't find a recent description of how the EPA currently tests city driving, but a 2009 C&D description of the EPA's 11 mile dynamometer simulation (see link to follow) included stops about every 1/2 mile among other parameters and a top speed of 56 mph. If that has not changed much "city" would more closely approximate what many people experience in the suburbs, or even much worse than "city" in suburban rush hour congestion. The devil really is in the details. Among my top 100 life lessons is that's where you'll typically find Old Scratch, but I digress.


On my most recent 240 mile fill-up (AWD, 7500 mi. on the OD), most of the miles on two-lanes with stops 1 - 3 miles apart, with several 1 mile each way hops to the golf course, a couple 4 miles each way to and through the village with multiple stops, and a couple 5 miles each way of suburban driving on the way to a shopping district, the vehicle showed 27.4 while my controlled manual measure was 26.4. That's in normal mode, mostly flat land driving except for a few 300 foot climbs up the Niagara Escarpment, with fairly aggressive gas into third gear to avoid the low gear lugging I've commented on ad nauseum.

The only pure highway driving I've done was the day I bought it with 4,000 miles on the OD. Started with a full tank, hopped right on the expressway, drove 200 miles with no stops or snags, free sailing at 70-75 except 55 through downtown Buffalo. It was flat land driving downwind but my wife was in the vehicle and my AWD is hauling about 140 more pounds of curb weight than your FWD. At one point the vehicle's mpg reading touched 33 and finished in the upper 32s for that trip according to the vehicle's reading. Subtract 1 mpg for vehicle overstatement and that puts the trip in the upper 31s. Had I been driving upwind with some 20-30 mph difference in wind resistance (10-15 mph in each direction) results would have been somewhat lower.

I reckon my vehicle is right about where it is supposed to be with a 25 City/31 Highway rating given the 25 is somewhere between optimal city conditions and fanciful.

Situational details could account for what you said, except 26 mpg in true highway driving, free flowing expressway with no stops or snags, is meaningfully lower than my experience.
 
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The trip computer says it has gotten 26.6 mpg over those 2052 miles. When I calculate it’s mpg over those same miles, it’s getting 25.4 mpg, so the car’s computer is off by 1.2 mpg.
That is consistent with a couple of controlled spot checks I've done. For example, here's the steps of my top off test done today:
  1. Filled the tank to auto shut off on the previous fill-up. No over-pumping.
  2. Zeroed out the trip mpg readout.
  3. Drove 238.1 miles per the trip meter.
  4. Filled up at the same pump as prior up to auto shut off. No over pumping
  5. The pump read 9.002 gallons.
That's 26.4 mpg. The vehicle read 27.4.

Now it's possible the pump is inaccurate, having pumped 8.7 gallons in fact which would match the 27.4 vehicle reading. I've gotten a similar 1 mpg difference on another spot check at a different pump at the same station. It's not likely the station is intentionally skimming at every pump since an inspection might draw a fine or loss of business license. Since this is the most convenient Top Tier station near home (Exxon, 87 octane, 10% ethanol, for what that's worth), I suppose I'll check at another station when the opportunity arises, but I wouldn't expect anything different.

In my other three most recent vehicles, two Toyotas and a Honda, the speedometer would read 1-2 mph faster than my Garmin GPS. I suspected but didn't jump through hoops to try to figure out if those vehicles were overstating miles driven and mpgs. I'm pleased to report my CX-5 odometer reads spot on with the Garmin.
 
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Not my first CX-5 and I was getting nearly 31 MPG on my last one.
It dawns on me now that you didn't mention which previous CX-5 you had. The 2013, for example, had a 155 hp 2.0L, was pulling meaningfully lower curb weight, and as one might expect had a higher EPA rating--26 city/35 highway. Are you comparing apples to apples?
 
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I dawns on me now that you didn't mention which previous CX-5 you had. The 2013, for example, had a 155 hp 2.0L, was pulling meaningfully lower curb weight, and as one might expect had a higher EPA rating--26 city/35 highway. Are you comparing apples to apples?
2019 Touring
 
2019 Touring
Then it stands to reason since your current GT is essentially the same vehicle mechanically as the previous you should get similar gas mileage with the same driving style and traffic conditions, right? After doing a couple of manual mpg checks to confirm, I think you'd have something to address with dealer service.
 
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Having dead weight such as a hitch will decrease your overall mpg but not 5 like you're experiencing now. Definitely drive a bit more because you've only burned thru 2 tanks of gas.
 
@P-51 Lover I have less than 500 miles so I think it'll be fair ....

Again, I gotta give it a couple hundred more miles and see if it gets better. And like I mentioned before my prior CX5 was getting about 30 MPG on a Hwy (70-75 MPH).
More like a couple of thousand miles. At 500 miles you haven't driven it through the second tank full even. It's time to start stressing the engine with RPM and cylinder pressure (more throttle) to get a good break-in. My average mileage improved, slightly, through 5000 miles, but as stated, the improvement was on the order of 2 mpg, max.

Seasonal/regional reformulation and ethanol contamination all will reduce fuel mileage. In the cars I've had recently, 10% ethanol reduced mileage 8 - 10%.
 
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