Just got a 2016.5 CX-5 - Tips, Tricks and MPG

[Irenicus]

Just clocked a whopping 18MPG on a tank in city driving.... never really imagined this thing would get such bad gas mileage. Good thing I really like it but my god it's basically on par with a lot of large trucks. I can't possibly drive any lighter or do anything to improve the MPG either. Ouch

 

[N7turbo]

Just clocked a whopping 18MPG on a tank in city driving.... never really imagined this thing would get such bad gas mileage. Good thing I really like it but my god it's basically on par with a lot of large trucks. I can't possibly drive any lighter or do anything to improve the MPG either. Ouch

Describe your city driving. Do you mean stop and go, speeds 35mph and below, for the entire tank?

 

[AL Cx5]

Just clocked a whopping 18MPG on a tank in city driving.... never really imagined this thing would get such bad gas mileage. Good thing I really like it but my god it's basically on par with a lot of large trucks. I can't possibly drive any lighter or do anything to improve the MPG either. Ouch

X2 @N7turbo. There are no silver bullets. Do this one simple thing and poof better FE. Rather an accumulation of small changes in behavior.

I get 2 to 3 MPG better than my wife. She doesn't have a lead foot either.

I call it conscious driving. It's not that important to her to get better FE. She is enjoying the music or conversation. I'm looking way down the road and see the light change and coast to the light and many other simple things. I've been doing it so long, now it's a habit.

At the lights, I'll put the trans in neutral. Not a legal maneuver. My digital dash on my truck shows the engine load drops from 14% to 3% when stopped, in gear vs. out of gear.

Tire pressure and alignment will eat into FE big time too. I just had 4 new tires mounted on the CX 5. When I got home, not 1 tire pressure matched the others. Some over inflated, others under inflated. I have a digital tire pressure gauge to check the tires. When there is a big drop in temp, I check the pressures and add air. Waiting for the idiot light is too late. Tire life suffers as well as FE.

I'll throw in tire balance as well. Like under pressure, this will eat into FE. Even worn suspension hurts FE. We upgraded our coilovers, sway bars, bushings and wheels the first 1000 miles. The car is tight, no slop or wiggle. It tracks like it's on rails. We drive it down the highway with 2 fingers on the wheel.

All the sensors on the car have to be in good working order. As the sensors age, they loose calibration and send inaccurate info to the ECU. The ECU trims the fuel and timing based on this info. On my 19 year old, 275K mile truck it's sensors have with less than 50K on them. I saw a 2 MPG increase in FE when changing to new engine management sensors.

Are your brake dragging? I've chased this issue before. With an infrared gun, shoot each dish after a soft stop.

In the end, to get good FE, everything on the car needs to be like new or better. It could be an accumulation of items.

Are you willing to make any simple, inexpensive mods to your car? And/or get it tuned? This is the first car I rushed to get all my FE mods in place the first 1000 miles. We're glad we did it and now we just drive it. These will pay for themselves many times over over the life of the car.

I notice a bump in FE with Stabil fuel additive. The car just plane runs better with this stuff and is more FE.

In city driving could be creeping along and stopping every block vs little to no traffic on an inner city 4 lane. We are about almost two tanks average intown and short trips, less than 40 miles on the interstate. My wife drives the car about 75% of the time. Our LOM is near 25.5 MPG. Many of our trips, the car never gets fully warmed up and FE suffers. We use the gas burner for short trips and try not to start the diesel unless it's a long enough trip to get it warmed up, this take up to 40 miles...

Try a 100 mile or more interstate drive. Stay 5 MPH under the speed limit in the right lane and if you have to, plan passes way in advance. Pass down hills and so forth. Conscious driving becomes a game for me. On another forum us FE nerds exchange mods and driving technics that apply to our CX 5s. You are right, my old technology, 4 spd auto, 2500, diesel pickup gets 18 in town and 22 to 23 highway with up to 4000 pounds in the bed. Hand calculated.

If your ride is not in the high 20 to low 30s on the above trip, it's time to start looking at some things.

The LOM on these cars is pretty accurate. I check it with hand calculations and it's within 1 MPG range most of the time. Have you checked your LOM vs hand calculated?

 

[N7turbo]

At the lights, I'll put the trans in neutral. Not a legal maneuver. My digital dash on my truck shows the engine load drops from 14% to 3% when stopped, in gear vs. out of gear.

You might see less of an improvement on a Mazda since they program the TCU with Neutral Idle Control.

Also: cool/cold engines are less efficient. It's one of the main reasons fuel economy drops during the winter months in the United States. Not much we can do about that.

 

[AL Cx5]

You might see less of an improvement on a Mazda since they program the TCU with Neutral Idle Control.

Also: cool/cold engines are less efficient. It's one of the main reasons fuel economy drops during the winter months in the United States. Not much we can do about that.

Agreed, 10% difference in gear vs out of gear is a big. I'll see if my Torque app has engine load PID for Mazda's and check. Even a 19 year old domestic dinosaur ECU adjusts for neutral vs in gear.

On that note, back to some of our other discussions, even though the Mazda has a lot of techno bells and whistles the engine efficiency is underwhelming. The HP/Ci ratio is much lower than modern domestic pushrod V8s. I STILL like the forged crank shaft and connecting rods on these engines. I'll have a look at Torque. If not, fire up Mazda Edit. Maybe your DD has an engine load PID too?

Agreed, winter reduces FE. I guess unless it's a gov mandate, the car manufactures won't take any further steps to help FE or pollution on cold engines. They could have coolant and oil heaters standard on all vehicles and easy to plug into a 110 outlet.

I put grill covers and winter cover over the cooling stack on my truck in the winter. After it warms up, FE is on par with in the summer. For those FE nerds, an inexpensive magnetic heater on the oil pan helps warm up time and the engine will likes it. I have two on the 3 gal diesel oil pan. On the Mazda, even though the ECT is above the blue, I suspect the oil temp is still low and the oil viscosity is high hurting FE. As we all know, a cold start is where most engine wear occurs. Maybe it's by design to help wear out the engine and we buy a new car....

I bought a block heater for the Mazda but have not installed it. It's pretty far down on my list. The CX 5 is a garage queen, we live in the south and don't have sever winters. Lastly, I don't want to over complicate this car for my wife. I DO see a nice bump in FE preheating coolant and oil on the diesel and would have these features on the Mazda if I was the only driver.

 

[Lazy2.5]

@AL Cx5 I also put my car in neutral at the lights. Anything to note when doing this?

 

[a69mach1377]

@AL Cx5 I also put my car in neutral at the lights. Anything to note when doing this?

Yes...don't forget it's in neutral, lol
Don't ask how I know...

 

[stickerbush]

What is the thinking behind a putting car in neutral at stops?

 

[Lazy2.5]

What is the thinking behind a putting car in neutral at stops?

so i don't have to press my brakes that much harder. Doesn't make sense to fight the transmission when i'm not yet taking off. Also, reduction in engine load like @AL Cx5 mentioned.

 

[AL Cx5]

so i don't have to press my brakes that much harder. Doesn't make sense to fight the transmission when i'm not yet taking off. Also, reduction in engine load like @AL Cx5 mentioned.

As noted in my LONG post, I've see over 10% engine load just to turn the transmission at idle. Engine load dropped to 2% when in neutral. This was in another platform and I'll work on confirming the load on our 24 CX 5 soon.

I've also noticed the trans runs cooler in stop and go traffic on the OTHER platform. Spinning the torque converter builds up heat.

 

[AL Cx5]

Here are screen shots with the trans in D or N using Mazda PIDs on a Torque app.

Car had been parked in the garage, not warmed up. One could make this a research project and graph the differences as fluid temps change. If you are so inclined, Id love to see it.

Warmed up fluids should be less but you get the drift it costs more to let the engine idle in gear. Ambient, 61F. The Ecu picked the idle rpm. It's not clear why it idles higher in N

NOW I want to check the AC power draw when it gets warm again.

Percent differentence engine load is 31% and 35% different Actual torque, Netrual vs. Drive. Wow.

I'm not surprised it's greater than a big, heavy rotating assembly, torquey 5.9 diesel. But it was a surprise to see the engine under this much load to pump trans fluid and spin a torque converter....

So it makes FE since to slip it into neutral when stopped if you are a FE nerd!

 

[Moonlighter]

As noted in my LONG post, I've see over 10% engine load just to turn the transmission at idle. Engine load dropped to 2% when in neutral. This was in another platform and I'll work on confirming the load on our 24 CX 5 soon.

I've also noticed the trans runs cooler in stop and go traffic on the OTHER platform. Spinning the torque converter builds up heat.

iStop takes care of all of that…..

 

[AL Cx5]

iStop takes care of all of that…..

For sure.

Thankfully I don't have this "feature".....

 

[Moonlighter]

For sure.

Thankfully I don't have this "feature".....

It works just fine.

 

[Kedis82ZE8]

@AL Cx5 I also put my car in neutral at the lights. Anything to note when doing this?

I don’t know if this applies to ATs in our Mazdas but I was always told this was a big no-no with some transmissions as it disrupted AT coolant flow cooling.

Particularly vehicles that had been under significant load and AT fluid that was heated up fairly high. Something easy to do on hills and city driving.

 

[Mazdiod2]

Shutting off the engine while it's hot can cause gurgling. I've experienced it in my old Mazda 626. I thought there was some kind of little critter under the hood making noise but it was the coolant making noise in the heater core.

 

[AL Cx5]

I don’t know if this applies to ATs in our Mazdas but I was always told this was a big no-no with some transmissions as it disrupted AT coolant flow cooling.

Particularly vehicles that had been under significant load and AT fluid that was heated up fairly high. Something easy to do on hills and city driving.

Interesting. I have a trans temp PID on a digital dash in my 2500 truck. I've witness the opposite. The trans runs cooler.

Your point is worth investigating on the Mazda. I'll see if there is a trans temp PID for my app.

On domestic vehicles they have a screen with items like trans and oil temp. It's very helpful to know when to back off when towing, trucks or road racing, cars. Mazda is your ai listening???

 

[Lazy2.5]

iStop takes care of all of that…..

Unfortunately north american vehicles did not get it. Another reason to put in neutral would be to shut the engine off at longer lights.

 

[stickerbush]

so i don't have to press my brakes that much harder. Doesn't make sense to fight the transmission when i'm not yet taking off.

My CX5 has a feature (forget exactly what it's called) where it will hold brakes on when stopped and you can take your foot off the pedal. It's enabled with a button in the console, must be enabled whenever you start the car, setting is not remembered when engine is switched off.

 

[7eregrine]

It's called "AUTO HOLD".