Preparing for winter with a comprehensive strategy to improve MPGs including grille blocking & more

[milleron]

You're not alone. Today, with the outside temp at 30 and after the car interior had reached a comfortable 65, I had to turn off the Climate because it started blowing cold air in my face. It felt like the AC was on. It doesn't happen often, but it does happen.

[hybridbear]

Mmhh it's coming from the dash vents.

It did it today maybe 4 times on my way to Detroit. Every so often I noticed a rush of cold air getting into the cabin. It was actually so uncomfortable that I adjusted the left center vent so it wouldn't blow on my knee.

 

The climate was set to all auto at 69*F it's really odd.

You're not alone. Today, with the outside temp at 30 and after the car interior had reached a comfortable 65, I had to turn off the Climate because it started blowing cold air in my face. It felt like the AC was on. It doesn't happen often, but it does happen.

Perhaps the interior cabin temp is getting warm enough that the car is switching to blow cool air. I've found on long highway trips that even with outside temps less than 10F, the air coming out the vents is cool after about 20-30 minutes because the interior of the car warms up so much. Driving long distances on the highway causes a lot of engine heat to naturally seep into the cabin since the wind is blowing all that heat back toward the firewall. We've found that inside the glove box is very warm after driving long freeway distances even on sub-zero days because of this. The MFT screen, HVAC buttons, dash glass, etc are all also very warm. Perhaps this is what you were feeling?

[milleron]

I do agree that it's happening because the cabin warmed, but it shouldn't. I've never experienced this unpleasant phenomenon in any other vehicle. It's a design or programming flaw. I'm not raising heck with anyone because it remains infrequent, but it sure is annoying when it happens. Just wanted to let corncobs know that his experience isn't unique.

[ptjones]

I do agree that it's happening because the cabin warmed, but it shouldn't. I've never experienced this unpleasant phenomenon in any other vehicle. It's a design or programming flaw. I'm not raising heck with anyone because it remains infrequent, but it sure is annoying when it happens. Just wanted to let corncobs know that his experience isn't unique.

You could turn on recirculate and fix the problem, and save gas too. :)

 

Paul

[acdii]

If you are running on auto mode, this will happen. I just have mine set on windshield and floor and adjust blower speed, never got any cold air blasting this way, but have had it happen often when on Auto mode.

[milleron]

You could turn on recirculate and fix the problem, and save gas too. :)

 

Paul

Well, I'm always in recirculate mode in AC season, but in the winter, that leads to window fogging in short order, at least when it's as cold as it has been here in Nome, Ohio, this year. The only real use for recirculate this time of year is for heating the car when you first engage the Climate Control from a cold start, but even then you have to turn it off fairly soon after invoking it.

But if it were possible to use recirculate in the winter, how would that work to alleviate this problem?

[acdii]

It wont. The auto climate will try to regulate inside temps, and will do it either by bypassing recirculate or turning on the AC.

[ptjones]

It wont. The auto climate will try to regulate inside temps, and will do it either by bypassing recirculate or turning on the AC.

I usually use the manual mode with AC off with center and lower vents on with recirculate on to save gas. When windows fog I hit defrost for 30 sec. and then turn it off. Then back to lower and middle vents. I believe this is the most economical solution and you will never get cold air. IMO :)

 

Paul

[acdii]

Defrost and floor position does pretty good too.

[corncobs]

Thanks guys for confirmation I made it back safely and it happened more frequently today due to the warmer temps (45*F).

 

Btw I got 39.5 MPG in 340 miles in a little bit over 5.5 hours. I-290 was really a mess this afternoon so it took a bit longer to get home.

[KLH]

Just chiming in on the plexiglass grille cover, which I've been using for the last month or so. I have recently removed it "just to see" and yes - there is a significant difference.

Without:

* Takes about 7 minutes to get engine warm enough to generate heat

* Average mileage is ~38

With:

* Takes about 4 minutes to get engine warm enough to generate heat

* Average milease is ~41

FWIW, I've been driving in 8-10* weather and the cover's impact is immediately noticeable. Heat comes (much) faster and EV mode is available much faster as well. I think that the product does exactly what it's intended to do.

As always, YMMV. In this case, the only thing I don't recommend doing with a grille cover is to get a car wash! LOL!

[hybridbear]

Temps recently have been climbing above freezing here so I've been monitoring temps carefully to determine when to remove grille blocking. I have removed about half of the foam from the very bottom row of the lower grille at the bottom of the bumper and about half from the very top row of the top grille up near the hood.

 

On a ~40 mile freeway trip on Saturday with outside temps near 50 the coolant peaked at 213 F and mostly stayed between 195 & 205 F. The hybrid components mostly stayed in their normal ranges of 100-120 F. Yesterday with a temps between 30F in the morning and 60 F in the afternoon I found in short city trips (longest was under 12 miles) that the coolant temp barely reached 200 F. The hybrid components temps behaved exactly as at 20 F. I plan to make some changes before Wednesday and then monitor temps the upcoming week or so based on completely removing the foam from the lower grille.

[tr7driver]

I must have missed that you blocked both the lower and upper grills. I only did the upper. Did blocking the lower result in any significant improvement or danger?

[ptjones]

Temps recently have been climbing above freezing here so I've been monitoring temps carefully to determine when to remove grille blocking. I have removed about half of the foam from the very bottom row of the lower grille at the bottom of the bumper and about half from the very top row of the top grille up near the hood.

 

On a ~40 mile freeway trip on Saturday with outside temps near 50 the coolant peaked at 213 F and mostly stayed between 195 & 205 F. The hybrid components mostly stayed in their normal ranges of 100-120 F. Yesterday with a temps between 30F in the morning and 60 F in the afternoon I found in short city trips (longest was under 12 miles) that the coolant temp barely reached 200 F. The hybrid components temps behaved exactly as at 20 F. I plan to make some changes before Wednesday and then monitor temps the upcoming week or so based on completely removing the foam from the lower grille.

Just a reminder that at slow speeds shutters open at 210*F and FWY speeds they open at 215*F Removing bottom cover lowers WT about 5*F when I was testing 2014 FFH. :)

 

Paul

Edited April 19, 2014 by ptjones

[hybridbear]

I must have missed that you blocked both the lower and upper grills. I only did the upper. Did blocking the lower result in any significant improvement or danger?

Not sure. I'd like to believe that it helps raise our temps even more in the frigid winter. I have not had the opportunity to test with the lower grille completely open to see how it performs.

[tr7driver]

I'm headed to New Jersey this week, so I pulled the insulation out last night. I'll be interested to see what the MPG is over the next couple of days. We have been seeing trips on the upper 40 mpg last week and my lifetime avg has jumped from 33.4 to 39.1 in the past 2 weeks. This will be our first road trip with the car, so it will be interesting to see how it travels. We only have 2,200 miles on it so far.

[hybridbear]

Grille covers update:

Last night I took off the plastic clear lower grille cover from acdii and replaced it with foam. I didn't put foam in the small area around the driver's side of the license plate. This area is open for venting. All of the top grille is blocked and the very bottom lip of the bumper is also blocked. Today we've been on the road driving to Winnipeg and I've been monitoring the temps. Ambient temps have been 40-45F.

 

Here are some notes:

The sun makes a big difference. When the sun was out the coolant temp was consistently 220-230F. This is still completely within the middle zone of the temp gauge. There is no visible difference on the MyView temp gauge at 230F compared to 190F. The intake temps were consistently 84F at this time. Driving at 65 MPH with adaptive cruise we've seen MPGs of 38.5 so far according to the car. MPGs have been very consistent.

 

Once the sun went down the temps dropped. The coolant temp dropped to 190-197F and the intake temp dropped to 68F.

 

The motor inverter temp was consistently 90-110F and the generator inverter temp was consistently 105-125F. This leaves me very content with the grille blocking with the foam.

 

When we come home next week the ambient temp is supposed to be in the mid-30s when we leave Winnipeg in the morning and close to 70F in Minneapolis. I plan to remove some foam from the lower grille before we leave Winnipeg and then I'll monitor the trip home at higher ambient temps to see what happens.

 

Check out the pic below of the old grille blocking with the clear plastic from acdii.

Edited April 18, 2014 by hybridbear

[hybridbear]

Ambient temps have now dropped to 35F and the coolant temp has dropped to 185F and the intake temp is down to 65F. I'm very comfortable with this full grille blocking.

[hybridbear]

After we turned off the car and restarted then the coolant temps went back up to 220-225F. The intake temp was 68F all the way from the border to Winnipeg. My theory is that before we reached the border the grille shutters were open and they didn't close with the dropping temps and thus the coolant temp dropped. When we turned off the car the grille shutters must have closed which led to coolant temps of 220-225 with ambient temps as low as 20F.

[ptjones]

After we turned off the car and restarted then the coolant temps went back up to 220-225F. The intake temp was 68F all the way from the border to Winnipeg. My theory is that before we reached the border the grille shutters were open and they didn't close with the dropping temps and thus the coolant temp dropped. When we turned off the car the grille shutters must have closed which led to coolant temps of 220-225 with ambient temps as low as 20F.

It has been my experience that the Shutters open when you stop and you can hear them open. When you put the car in gear and start moving the shutters close if WT is below 210*F. Shutters are always open above 215*F. Generally WT goes up with increased speed and when gaining elevation. :)

 

Paul

[acdii]

Did you take into account heat soaking?

[ptjones]

Did you take into account heat soaking?

I'm not sure what you are referring to. The Shutters are always open when you stop the car. :)

 

Paul

[hybridbear]

Did you take into account heat soaking?

The temps I'm talking about are the coolant temps while driving on the freeway at a sustained 65 MPH. The ICE doesn't turn off at those speeds on the perfectly flat prairie roads so there's no variation in coolant temp with EV Mode. There's also no variation due to hills, just flat prairies and consistent temps for hours at a time.

[acdii]

You mentioned turning it off and back on and the temps were higher after turning it back on, which leads me to believe it was due to heat soaking. On the BD when I ran the SG on it, I always saw the temps rise when I came to a stop and the ICE shut off for a bit due to heat soaking.

[ptjones]

I also see the same temp rise on the HWY when the car goes to EV for a while. Interesting for me I still go to EV on flat land, maybe some P&G going on. :)

 

Paul