CX-5 Fuel economy and range all over the place

[Mreed1988]

Hello.

Sadly the other day I discovered my battery dead in my mazda cx5. I jumped the car and had a sequence or error messages the first was about the parking brake and then about the battery management system failure and Istop. All these messages have cleared themselves but I am now finding the cars fuel economy to be shocking. Before this happened I was averaging around 42 mpg now I'm struggling with around 32/33. I have also noticed the fuel range to be very up and down having swings of 30 or 40 predicted miles.

What may have happened? Thanks.

 

[Gaspar]

I had this on my 2013 Touring. Since that number is an average it will 'settle down' as more miles get calculated.

 

[erhayes]

Disconnecting the battery probably reset all the sensor values to the default levels, your driving style will slowly return. Ed

 

[mutualcore]

How you are people getting these insane mileage numbers? I never got anything close to 30s, much less 40s on a full tank.

 

[itsdeekay]

How you are people getting these insane mileage numbers? I never got anything close to 30s, much less 40s on a full tank.

Consistently driving 35 mph everyday.

 

[dougal]

How you are people getting these insane mileage numbers? I never got anything close to 30s, much less 40s on a full tank.

On the highway, it is pretty simple. Set the speed to the speed limit plus 5 mph. In suburbia, don't accelerate to a red light or stop light. Accelerate quickly to the speed and back off the gas. And don't drive like you are in a S2000.

 

[yrwei52]

How you are people getting these insane mileage numbers? I never got anything close to 30s, much less 40s on a full tank.

OP has i-stop, he uses mpg, these means he could be in UK. His CX-5 could be a 2.2L diesel, averaging around 42 mpg is a possibility with bigger British gallon (1 Imperial Gallon = 1.201 US Liquid Gallons).

I simply can’t imagine OP can get 42 mpg averaging with a gasoline engine, even if he has a SkyAcyiv-G 2.0L and calculated with Imperial Gallon.

 

[bandanaman]

In the UK for this one - I filled up with petrol and 2 days later when I went to the car it was dead - the door would open (weirdly) but could not open boot or nothing on dash - I got a jump start and everything OK except radio memories wiped! - drove the car to ensure battery was ok - it took 20 mins for the range gauge to rise from 0 and it went all the way up to 506 miles (!!!!) - never shown anything higher than 435 miles - what could have caused this? - how reliable now?
When I switch engine off and restart the gauge shows a range of 506 miles ....
Car starts OK but I am wary - the key fob working OK - but it wouldn't before the jump start.
Not sure the battery was dead - it appears more that the 'systems' were dead which 'woke up' once the car started.
Ideas please

 

[Snorting2.5]

On the highway, it is pretty simple. Set the speed to the speed limit plus 5 mph. In suburbia, don't accelerate to a red light or stop light. Accelerate quickly to the speed and back off the gas. And don't drive like you are in a S2000.

You would think that being a sensible and efficient driver is the logical thing to do.

Majority of drivers on the road indicate otherwise.

 

[Charmer383]

I'll say it everytime I see a mpg thread. CX5 sucks for mpg. I won't recommend to anyone looking for a sensible SUV. My wifes 2022 Tuscon Limited gets better. I drive 66 miles for work daily. I rarely driver over 70mph. While the terrain is hilly I can't get any better then 25 overall. If I drive 55 max causing for a longer commute I see 27/28 on a trip.

 

[Snorting2.5]

I'll say it everytime I see a mpg thread. CX5 sucks for mpg. I won't recommend to anyone looking for a sensible SUV. My wifes 2022 Tuscon Limited gets better. I drive 66 miles for work daily. I rarely driver over 70mph. While the terrain is hilly I can't get any better then 25 overall. If I drive 55 max causing for a longer commute I see 27/28 on a trip.

My Mazda 6 with the same drivetrain, fully tuned, averages 40-45mpg.

44+ If I'm driving particularly conservative. Involves waiting for a downhill to speed up, otherwise just maintaining whatever momentum I have, coasting, gentle on the up hills.

 

[erhayes]

I have been averaging 25.6 mpg here in Cape Coral FL. I'm not a hyper miler but, just drive normally to go with the traffic flow in my city.

 

[Towser]

How old is the air filter? Changing it improved my CX-5 mileage.

 

[Charmer383]

How old is the air filter? Changing it improved my CX-5 mileage.

If your talking to me I have 7800 miles on it. From the gate it has sucked on mpg. I thought after a few thousand miles and oil change it would increase but it hasn't. To me it is the main flaw and will be the reason I don't stay with Mazda.

 

[Snorting2.5]

If your talking to me I have 7800 miles on it. From the gate it has sucked on mpg. I thought after a few thousand miles and oil change it would increase but it hasn't. To me it is the main flaw and will be the reason I don't stay with Mazda.

I don't see other crossovers Significantly more efficient.

Buy a smaller car, not a jacked up crossover.

 

[bandanaman]

I'll say it everytime I see a mpg thread. CX5 sucks for mpg. I won't recommend to anyone looking for a sensible SUV. My wifes 2022 Tuscon Limited gets better. I drive 66 miles for work daily. I rarely driver over 70mph. While the terrain is hilly I can't get any better then 25 overall. If I drive 55 max causing for a longer commute I see 27/28 on a trip.

How you are people getting these insane mileage numbers? I never got anything close to 30s, much less 40s on a full tank.

I get an average of 36 mpg - I drive like a 'bat outta hell' - coast at 77 mph on the motorways - WHEN I ONCE restricted my speed to a top speed of 60mph on a 400 mile trip I returned 44 mpg - this goes to show that IF you restricted speed to 56 mph max then 50 mpg is achievable .... (but a boring way to travel ....!)
This is in the UK, where roads are narrow, and driving is aggressive - generally.

 

[SimpleCanuck]

I get an average of 36 mpg - I drive like a 'bat outta hell' - coast at 77 mph on the motorways - WHEN I ONCE restricted my speed to a top speed of 60mph on a 400 mile trip I returned 44 mpg - this goes to show that IF you restricted speed to 56 mph max then 50 mpg is achievable .... (but a boring way to travel ....!)
This is in the UK, where roads are narrow, and driving is aggressive - generally.

Since you are in the UK, I am assuming you are measuring in Imperial gallons and not US gallons. The mpg figures are lower when measuring in US gallons.

With that said, my non-turbo CX-5 did 33mpg (US) on its longest trip which was mostly on 2-lane highways. That would be in the high 30s in mpg (Imperial).

 

[Conrad 16.5]

I get an average of 36 mpg - I drive like a 'bat outta hell' - coast at 77 mph on the motorways - WHEN I ONCE restricted my speed to a top speed of 60mph on a 400 mile trip I returned 44 mpg - this goes to show that IF you restricted speed to 56 mph max then 50 mpg is achievable .... (but a boring way to travel ....!)
This is in the UK, where roads are narrow, and driving is aggressive - generally.

Since you are in the UK, I am assuming you are measuring in Imperial gallons and not US gallons. The mpg figures are lower when measuring in US gallons.

With that said, my non-turbo CX-5 did 33mpg (US) on its longest trip which was mostly on 2-lane highways. That would be in the high 30s in mpg (Imperial).

The imperial gallon is 20% larger than a US gallon, plus the OP has a 2.0-liter motor while most of us have the 2.5.

 

[Charmer383]

We go to OBX in July. Western PA to Avon, NC. Can't wait to see what I get down and back. I'm gonna try to drive slow and air up the tires some. I hope for 30mpg.

 

[Charmer383]

I don't see other crossovers Significantly more efficient.

Buy a smaller car, not a jacked up crossover.

I had a chevy cruze prior to this. Great mpg but the miles starting getting high and along came the issues so I sold it. It was a 2013 with a auto 6 spd. Jump forward 10 years to this 2023 cx5 and it has a 6 spd while others are 7/8/9 speeds. Gearing and a transmission for mpg would help. My wife has a 23' Tucson and gets better mpg. Any guess why?