cold start winter warm up

[Dan PA]

In my area, we've had average temps of -20C dipping down with wind chills of -40C. my 2.0L 2013 CX-5 takes a while (say 5 to 10 minutes) to idle down, better if its been plugged in for at least 4 hours (and I do have my grill covered). DO the newer 2.5L versions warm up faster?

The colder it is outside the more horrid my fuel economy, I wonder if the larger displacement engine has better fuel economy.
Thoughts?

 

[paris1]

In my area, we've had average temps of -20C dipping down with wind chills of -40C. my 2.0L 2013 CX-5 takes a while (say 5 to 10 minutes) to idle down, better if its been plugged in for at least 4 hours (and I do have my grill covered). DO the newer 2.5L versions warm up faster?

The colder it is outside the more horrid my fuel economy, I wonder if the larger displacement engine has better fuel economy.

Isn't that rather counter-intuitive?

 

[dougal]

I have found that cold temps and warm up time absolutely kill the MPG. In fact, a 10 minute warm up time, on a half tank of gas, drops my MPG by 0.7. When the temps drop into the 20's my MPG is around 22. When it is really cold (sub 20's) closer to 20 PMG. However, once it gets closer to 40, my MPG is closer to 24. This is all city driving with only short trips (less than 20 minutes). This is all on a 2.5 2014 GT.

 

[V8toilet]

I've had the 2.0 sky cx5 and now the 2.5 and honestly I don't know if the 2.5 warms up any quicker. When its 5 degrees out I have to drive it about 2 miles on the highway + about a mile to get to the highway to get the cold indicator light to go out. The gas mileage is definitely worse with the 2.5. I average 2 mpg worse than I did with the 2.0 right now. The cold temperatures have caused me to lose about 15% in MPG. The 2.0 is a good engine for efficiency, I used to get a consistent 35+ mpg on the highway with that engine in automatic form and it did 0-60 mpg in 8.37-8.6 seconds measured with my G-tech, the 2.5 a traction limited 7.5 seconds.

 

[pjensen641]

In my area, we've had average temps of -20C dipping down with wind chills of -40C. my 2.0L 2013 CX-5 takes a while (say 5 to 10 minutes) to idle down, better if its been plugged in for at least 4 hours (and I do have my grill covered). DO the newer 2.5L versions warm up faster?

The colder it is outside the more horrid my fuel economy, I wonder if the larger displacement engine has better fuel economy.
Thoughts?

Are you allowing it to warm up for an extended period before driving? I would suggest against letting the engine warm up for more than a minute or two. It isn't very efficient to let it warm up with no load. The engine just doesn't create heat until you are driving under a load. Also, the transmission needs to warm up and that is best done by driving very conservatively for a few minutes.

I think the ideal warm up time is only long enough for the high idle "buzz" to go away. Maybe 30 seconds or so. Then drive 20-30 mph for a few minutes if possible. Try not to use your cabin heat until several minutes after the blue light goes away.

I have been able to raise my winter fuel economy 2-3 mpg by covering the grill and not using the cabin heat until the engine reaches 170F (which is about 2X as long as it takes for the blue light to go out.)

 

[Dan PA]

Are you allowing it to warm up for an extended period before driving? I would suggest against letting the engine warm up for more than a minute or two. It isn't very efficient to let it warm up with no load. The engine just doesn't create heat until you are driving under a load. Also, the transmission needs to warm up and that is best done by driving very conservatively for a few minutes.

I think the ideal warm up time is only long enough for the high idle "buzz" to go away. Maybe 30 seconds or so. Then drive 20-30 mph for a few minutes if possible. Try not to use your cabin heat until several minutes after the blue light goes away.

I have been able to raise my winter fuel economy 2-3 mpg by covering the grill and not using the cabin heat until the engine reaches 170F (which is about 2X as long as it takes for the blue light to go out.)

I don't know where you live, but if I did that, the engine in my vehicle would physically vibrate until it warmed up while driving. For instance the windchill this morning was -38C, -30C in the afternoon. I cannot plug in my vehicle at work, so I have to let it warm up for at least 5 minutes, once I start driving around the blue light will go out. If I don't let it idle down before I drive, the "instant" fuel usage gauge is atrocious and like I said before, the car physically vibrates.

 

[pjensen641]

I don't know where you live, but if I did that, the engine in my vehicle would physically vibrate until it warmed up while driving. For instance the windchill this morning was -38C, -30C in the afternoon. I cannot plug in my vehicle at work, so I have to let it warm up for at least 5 minutes, once I start driving around the blue light will go out. If I don't let it idle down before I drive, the "instant" fuel usage gauge is atrocious and like I said before, the car physically vibrates.

I've been doing this method down to -30C without the vehicle plugged in. It does sleep in an unheated garage which keeps the temps 5-10 above ambient.

Your claim that the instant MPG is bad if you don't let it warm up is probably true....its much worse if you let it warm up. Think about it, even 5mpg is better than 0mpg!! You are still burning that fuel. Its just that you aren't getting any distance out of it when it sits around warming up.

 

[V8toilet]

I have been able to raise my winter fuel economy 2-3 mpg by covering the grill and not using the cabin heat until the engine reaches 170F (which is about 2X as long as it takes for the blue light to go out.)

I'm curious what you used to cover the grill with?

 

[CXVille]

I don't know where you live, but if I did that, the engine in my vehicle would physically vibrate until it warmed up while driving. For instance the windchill this morning was -38C, -30C in the afternoon. I cannot plug in my vehicle at work, so I have to let it warm up for at least 5 minutes, once I start driving around the blue light will go out. If I don't let it idle down before I drive, the "instant" fuel usage gauge is atrocious and like I said before, the car physically vibrates.

the mileage while idling is worse. It is zero. The vibration is because the engine is in a different mode with different cam timing, I forget the details. It will warm up much faster driving than idling. The blue light goes out when the water temperature reaches about 130 F or 54C. The efficiency of the engine means that it does not produce much heat at idle and so it takes a loooooooong time to warm up at idle.

 

[pjensen641]

I'm curious what you used to cover the grill with?

I covered the entire lower grill and about 2/3rds of the upper grill with black Coroplast. Coroplast is the corrugated plastic that is used for things like small campaign signs people stick in their yard. I have it zip-ted to the front of the grill. with black zip ties. It looks better than it sounds, I'll have to snap a couple pics. I got the Coroplast from a local sign shop for like $8

I used some cardboard to cut a pattern to fit tight against the upper chrome trim of the upper grill, and tight around the Mazda emblem. I trimmed the lower half to match the curvature of the bottom of the upper grill, but trimmed enough to leave one line of grill holes exposed. Then I just traced it over to the Coroplast.

I use Dashcommand to monitor temps, and even with the grill blocked about 80%, my engine temp runs right around the thermostat opening temp of 175F. When it gets above 40F, I sometimes see it climb up close to 190F around town after a long highway stint. This is only for a few minutes though, and then its back down. When it gets up consistently in to the 50's, I'll probably throw a side cutters in the glove box to remove the lower block if needed.

This summer I plan to look in to adding custom grill shutters behind the grill. I may use an Arduino to control a servomotor based on Rad temp. Mazda should have done this from the start like all the new Fords and Chevy Cruze do!

 

[GAXIBM]

The new 3 GT with tech has active shutters...

 

[dougal]

The new 3 GT with tech has active shutters...

Yup and a bunch of other things that would be great in the CX-5, like a better head unit and i-Loop. If the 2016 CX-5 incorporates all the stuff from the 2014 3 and offers a Manual in the 2.5, that car is going to be an absolute killer!

 

[OctSK]

I don't know where you live, but if I did that, the engine in my vehicle would physically vibrate until it warmed up while driving. For instance the windchill this morning was -38C, -30C in the afternoon. I cannot plug in my vehicle at work, so I have to let it warm up for at least 5 minutes, once I start driving around the blue light will go out. If I don't let it idle down before I drive, the "instant" fuel usage gauge is atrocious and like I said before, the car physically vibrates.

I totally understand where you are coming from, given that I live 200km south of where you live. I park my 2.5 GS in a garage, I never let it warm up, I just hop in and go.
Over the summer, I averaged 8.0-8.3l/100km with the blue light going off after 1-2 minutes of light city driving.
Over the winter, I average 10-11l/100km with the blue light going off after 3-5 minutes of light city driving. If I race to time a traffic light, it goes out even quicker.
I do plug it all day at work; I also have another portable heater that I connected to the extension cord..so every time I get in the car after work, it is toasty warm and I don't crank up the car's heating at all. Didn't do my grill as you did but will do it as soon as I have a moment.
I did notice a drop in l/100km with the temperatures..worse at -30, less worse at -20, OKish at 0 to -10, perfect at 20-30 Celsius.

 

[Dan PA]

Sigh, no garage at home, no plug-in at work. My city has had about 30 days of -30C weather this winter season.
It's surprising the number of people who don't cover their grill on their vehicles.

 

[pjensen641]

I'm curious what you used to cover the grill with?

Here is my grill cover. I guess there is more than 1 row of holes open. Honestly wish I had kept a little more covered, but this helps a lot. Blocking out front and leaving a small slot of holes in the middle still allows air to flow through and distribute to the whole radiator. The old cardboard right on the radiator trick seems like it would create hot spots.

 

[V8toilet]

Here is my grill cover. I guess there is more than 1 row of holes open. Honestly wish I had kept a little more covered, but this helps a lot. Blocking out front and leaving a small slot of holes in the middle still allows air to flow through and distribute to the whole radiator. The old cardboard right on the radiator trick seems like it would create hot spots.

I like it, (thumb) I may have to try that! Thanks for taking the time to post those.

 

[Dan PA]

I have the top part of the grill covered, bottom is open.