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Now that summer is here, the A/C is not an option after 11:30am here in So.FL. It would be nice if we all could put our heads together for the most FE possible while running the A/C. Since last year, I’ve learn a bit on how to push the FEH for mileage that I never thought possible, so my mileage should be much better with the A/C this summer.

The High Voltage (HV) Battery has now began to run the A/C compressor while ICE ON, so cabin A/C might as well run also. For the FEH, the ideal battery temp is 82F, the desired range is 77F - 100F and the trouble code range is below -40F and above 135F according to the shop manual. So like it or not, the compressor is coming on if the FEH is sitting in the sun for long and the temp is above the 82F range when the ICE is running. GPSman said the A/C runs at 92F and above, but I’ve notice condensation near the drivers side rear wheel at lower temps. Also, he says the ICE will start to run the compressor for cooling the HV battery, but I have not had that happen. Anyone that can confirm this either way, help us out here.

The tricks to hypermiling with the A/C should apply to all makes and models, so I think this thread should be in the general information forum.

This past week, I did some drafting between 55-60mph with short P&G behind this truck that was as tall as it was long. During the pulse back to a good draft, I was accelerating at around 28mpg and gliding in neutral at ~120mpg with the A/C on. This helped by average, but without the draft, I was averaging around 35-39mpg depending on my speed in a 70mph limit. It’s nice to go slow behind someone else for a change.

Around town, I was able to go EV with normal recirculating A/C and stay in the ~45mpg tank average, but it’s getting hotter every day. After parking for awhile, I would put the windows down till most of the build up heat cooled off. BTW, I would crack the windows while it was sitting. Planning on a trip to get my front windows tinted real soon.

Lets have some feedback on improving mileage with the A/C running. Tell us what you know!

GaryG

Don't forget to park in the shade.

Between this Feb and the start of June, I was without A/C. Turns out it was a rat this winter that was nibbiling on my bird feed, then the A/C cable.

Turns out that parking under the shade at work and the garage at home was enough to cope with the Texas heat. Keep in mind that although some days were 95F, it will stay that warm longer and get past 100F :eek: Since my workplace allows a golf shirt, it worked. Would not have held out this long if a shirt and tie was required.

I often toggle the A/C like it was the brakes. ;)

Don't forget to park in the shade.
I second that, as a blinding hot parked car requires so much extra cooling -- the seats etc before the driver feels comfortable.

I haven't really used the A/C much to see what effect it has on FE. But have tried it once or twice, dialing the desired temp up to the high '70s and found that seemed to cool me off well enough in 5 minutes. Then I turned the compressor off and drove the rest of the way with just fan blowing on my face, outside vent closed and windows rolled up, so recirculating the cooled air long as possible.

But didn't like that the next day A/C AND FAN were both OFF, and the vent is expelling rather unpleasant warmish air. So I had to turn it on, dial the temp back down to the '60s and turn everything off again to have things back to normal.

Trouble is for like me the parking lot has NO trees or covers, uggh. kevin

John, I should have said battery temp instead of refering to outside temp. Today, the ICE took awhile to shut down, and it appears to be because of the battery A/C running. I still am looking for a ICE start because of battery temp though.

From a cold start this morning till I reached my 20 mile commute, I averaged a little over 49mpg. Not sure how much the battery A/C ran, but that was with no cabin A/C. The return trip was hotter, and my average was 47-48mpg when I noticed the ICE not shutting down two times with all my tricks. It took about one minute of idle at a stop to shut down.

GaryG

Today, the ICE took awhile to shut down, and it appears to be because of the battery A/C running. I still am looking for a ICE start because of battery temp though.

I noticed the ICE not shutting down two times with all my tricks. It took about one minute of idle at a stop to shut down.

GaryG
To be honest with all of you – I have not noticed, with the AC running, that the ICE runs any more than normal. What I have noticed is the rear battery powered AC coming on while I am in EV or while the ICE is completely shut down. I guess since on the FEH the auxiliary battery AC unit must be powered by the battery (don’t know if it is the 12V or 330V) it does run for a while after shut-down – at least until I open the door and shut the system down. This afternoon I noticed that it came on when I turned the key on (not starting it yet). I got out to make sure it was the rear AC and was correct. Guess it takes the coolant and cools the battery – ICE on or not. At first I thought the noise was coming from say an electric radiator cooling fan.

I’m with Gary on the not seeing the ICE come on for battery cooling. As said – if that is going to be the case, might as well just cut the thing on and keep me cool also. I see the coolant lines coming from the front and have noticed one line to be cooler, so that had to have come from the front AC unit (which is run off the ICE). So I guess the AC could have come on while in one of my short stints of the ICE running – but then the battery powered rear unit would have to be running the rest of the time. Think about it – if it is used to cool the battery during charging (heat build-up) and the main AC had to do all the work then the ICE would never shut down, but it does and the other takes over. I would also think that as long as that unit can do the job that is all that is necessary to keep the battery cool.

Don’t know if any of this makes sense but at least it is a shot in the dark. :)

Update –

OK this morning on my way to work I decided to see if I could tell if the A/C came on and ran - even though I had not turned it on.

When I parked at work I popped the hood and sure enough the high-pressure side coming out of the ICE A/C was cool and had condensation on it. Went to the rear to check the high-pressure line coming from the front to the auxiliary battery air conditioning cooling module (http://www.visteon.com/products/automotive/battery_cooling.shtml) - same thing.

So at some point the ICE A/C DID come on to assist in cooling the battery. So I guess our deduction that we might as well cool the cabin – and us – as long as the ICE A/C is going to be coming on anyway is correct. The MPG is going to take a hit anyway you go.

So I guess we are caught between a rock and a hard place.

In the winter we have to wait till all things heat-up to a point where we can go to EV and even then the ICE A/C also comes on to keep HV battery at its optimum temp.

In Summer, generally, it is going to be to hot for the HV battery – so keeping the cabin cool should keep the temp down and help the auxiliary unit. . If I am correct, and from other post, even parking in the shade with the outside temp over 77°F (the desired range is 77F - 100F), the A/C will turn on no matter what.

Wonder if taking off the carpet cover and letting the cool cabin air be in direct contact with the metal HV enclosure would help? The cover could be acting as a blanket and interrupting the dissipation of heat.

Hey Phillip

Looking in the manual, the TBCM can send a message to the PCM to enable the A/C compressor. At what temp of the battery, if any, can the PCM start the ICE from EV mode to cool the battery is the question. There is no question that the PCM will never start the ICE in the Key-OFF position. My thinking is, if the battery temp is controlling the A/C compressor during ICE-ON because the outside temp will not provide any cooling effect, you might as well have the cabin A/C on normal recirc.

The TBCM determines if the outside vent door should close, and if the two battery fans should recirc air through the condenser to the battery compartment. There should not be much cooling effect to the battery without the compressor turning by the ICE. At best, the residual cool air may last a short time till the heat of the battery has warmed that air. This may be the point that the TBCM reopens the outside vent door till the ICE restarts.

It does appear that the addition of the cabin A/C on top of the battery A/C, does drop my mileage more in hot weather. This maybe because the PCM can automatically disengages the compressor clutch during battery cooling only. The A/C is manual in the cabin, so the compressor stays on as long the ICE is running. A light when the battery is cooled by the compressor would be nice and something to think about as a MOD.

GaryG

Hey Phillip

A light when the battery is cooled by the compressor would be nice and something to think about as a MOD.

GaryG Funny - I was just thinking about that same thing - say putting an LED inline so when the compressor is on for HV battery cooling you could turn on the cabin air, but as you stated - you would need to know that the PCM is calling for the compressor to come on - otherwise the LED would stay on because you are requesting the A/C to be on.

Does the ScanGuage read this type code being sent?

It would be nice to be able to have it set on 'standard – no A/C air flow' and when the PCM calls for the compressor for battery cooling, the air is circulated thru the cabin condenser for cooling at that time only, then the PCM is also controlling the cabin temp.

Phillip, I was thinking of just monitoring when the compressor goes on and off for battery cooling. Knowing the outside temp, and how the amount of EV and battery recharge is effecting the use of the compressor, will determine if running the cabin A/C will make little difference. The SG does not give the compressor or battery info.

It sounds like you have concluded as I have, max EV will yield the best FE. My technique of keeping the battery near the bottom of the SoC and using two fake shifts to bring it back to EV for the P&G, seems to hold my tank average between 45-46mpg in the heat so far. After all, the ICE is only running a few blocks at a time. When I’m on roads that I can use this mode, the cabin A/C does not hurt that average much. It’s when I must stop long for lights (get’s to hot in the cabin) or travel speeds above EV that I’m starting to get mpg hits below 45mpg. High speed P&G with the A/C and ICE on is not that bad also.

Last summer, I found that keeping the fan speed on “1" kepts cool air blowing on the front passengers the longest when going EV in the normal recirc A/C mode. I used the “2" fan speed as a max speed. Also, thinking about using light weight blow up rafts or air mattresses (the wife wouldn’t want me using Dolls and a air mattress) to reduce the air volume to be cooled in the lower half of the rear seats and cargo area. Maybe fold the seats down and stack the rafts just so you can see traffic through the back window. If I needed to make room for someone or something, just pull the plugs. Any thoughts or ideas?

GaryG

Yesterday, I went to get my front windows tinted to better prepare for the hot weather. The place I go gives a lifetime warranty and uses the best materials. Never had a problem so far with returns. They told me to keep my windows up for three days, so the A/C goes on as soon as I get rolling. Of course, I left the battery drained when I parked when I got there, so starting on my return trip home was going to be a challenge in the FE department. The outside temp was 92F.

Notice right away the tinting had a big effect on the A/C cooling faster and lasting longer in EV mode. It was hard raising my SG mpg current trip starting back home 20 miles away, but I wanted to put the FEH to a challenge while staying cool. The roads I took (Military Trail) had medium traffic with stop lights about every 1-2 miles and the speed limit was 45mph till I got close to home. I did a lot of pulses to 50mph and gliding down to ~42mph in neutral with the A/C running and cooling nicely. Of course the battery got on the half to full SoC many times, and when traffic permitted, I drop to 40mph and went EV and maintained 35mph till traffic would cause an increase in my speed. The A/C maintained a nice cool cabin and battery temp for going EV with no problems. After ~10 miles, the current SG average had broke 40mpg and was rising just fine. The MPG ranged between the high 44's to the high 45's after 15 miles and finish with 45.6 in my driveway.

This represents about a 10mpg increase over last summer running the A/C. Last year I would have taken I-95 and jumped a draft to run the A/C. Monday, I have to take my Mother to So. Miami (100 miles one way) for some medical test and I'll post a comparison of highway driving with the A/C.

GaryG

The trip to Miami monday taking Florida's Turpike down and I-95 back ranged between 38.2 - 39mpg with the A/C on. Drafting was at speeds above 70mph, so I did alot of high speed P&G and found that to be the trick to stay around 70mph and hold that MPG. On the way back, I was in a hurry to get to the WPB Court House to pick up some work before they closed. Still pulled into my driveway at 39mpg for the 208 mile trip of mostly highway speeds of 70+ mph and A/C on the entire trip. Neutral gliding was the key if your in a hurry and also helped with Tropical Storm Alberto in the Gulf causing wind and rain here in So FL.

All and all, the mpg was not bad considering the speed and conditions. Miami is no place for me with those crazy drivers in that traffic. Took me a day to get calmed down, and now I must work on this tank average. Never thought I would love city driving so much better. A nice long drive along the beach will get me back in the saddle I think.

GaryG

40-ish MPG is pretty incredible considering those speeds and A/C use! That's similar to what the Accord can do, but I have to be extremely selective about when the compressor is allowed to run. Up-hill or accelerating, no way. I only let it take the hit on down-hill or very flat sections of road, and only just long enough to get some cooler air circulating before it gets shut down again. The target highway speed was about 60mph, too.

Between this Feb and the start of June, I was without A/C. Turns out it was a rat this winter that was nibbiling on my bird feed, then the A/C cable.

Turns out that parking under the shade at work and the garage at home was enough to cope with the Texas heat. Keep in mind that although some days were 95F, it will stay that warm longer and get past 100F :eek: Since my workplace allows a golf shirt, it worked. Would not have held out this long if a shirt and tie was required.

I often toggle the A/C like it was the brakes. ;)On your last comment, a hearty "Me too!" especially if I have passengers in the vehicle with me. Most often, my passengers are my parents or mother- and father-in-law. If it's "just" me and my hubby, he's learned to tolerate whatever temperature ranges I put him through; I'm usually the one to wimp out first, anyway. I don't tolerate temperature extremes well, especially not on the high end of the thermometer.

Parking in shade makes worlds of difference. We secured a primo parking spot last weekend at the movie theatre (to see {CARS} -- loved it!) and between the shade of a large tree and the windshield sun shade I use anytime the vehicle's parked outside, it was no hotter inside than if the vehicle had been sitting in our west-facing garage during the heat of the day.

Parking at my parents house, however, is a nightmare -- no shade available (unless I were to park in their yard ;)) and it takes quite awhile to vent the heat even with the sunroof and windows open. I spent a good 7 minutes or more of my drive just trying to get the air to a breathable temperature.

Yesterday, I went to get my front windows tinted to better prepare for the hot weather. The place I go gives a lifetime warranty and uses the best materials. Never had a problem so far with returns. They told me to keep my windows up for three days, so the A/C goes on as soon as I get rolling. Of course, I left the battery drained when I parked when I got there, so starting on my return trip home was going to be a challenge in the FE department. The outside temp was 92F.
[...]
GaryGHow does the aftermarket tinting you had applied to your front windows compare to the factory tint on the rear windows and liftgate window? Is it a match, a close match, or an entirely different shade/color? I've been mulling over getting tint applied professionally to my front windows but don't want it to look strange compared to the factory tint.

Once the HV battery is fully recharged on the highway, the A/C load when gliding in neutral only drops the instant MPG a small amount to about 135mpg. I use the down side of a overpass to pick up speed to 75mph and glide down to 65mph depending on traffic, but 60mph was the slowest and 80 was the fastest. Also, the truckers seemed to be in a big hurry (maybe that's why they choose to pay for the Turpike), so I would take advantage and jump behind them to increase my speed to 75-80mph for a good glide. The drafts at those speeds with the wind, would lower my average overall, but accelerating was better behind them. The RPM's was the thing to hold down as much as possible. Holding my speed with the least amount of pedal and perhapes reducing speed a little till I got the oportunity to pulse back up also helped. The key for me is to take advantage of everything you can.

GaryG

Shannon, they matched my other windows perfect. The cost was $89.00 and it makes a big difference to the driver and front passenger. You need it more than I do, and I'm sorry I waited this long to get it done. So will you be sorry if you go another day without it. The stuff they used on my FEH was Formulaone AM-30 to get a match.

GaryG

Shannon, they matched my other windows perfect. The cost was $89.00 and it makes a big difference to the driver and front passenger. You need it more than I do, and I'm sorry I waited this long to get it done. So will you be sorry if you go another day without it. The stuff they used on my FEH was Formulaone AM-30 to get a match.

GaryGWho'd you have do it? A local body shop? Ford service? Pep Boys? Just curious. We have a chain called "Mother's Window Tint" that I think did the tint job on my husband's 2001 Ford F-150 and it's held up wonderfully. I definitely think it's worth the cost and with less fear of a bad match with the existing tint I have nothing standing in my way. I'll see if I can't get that done soon as it's gearing up to be a typical HOT Texas summer (last couple summers were comparably mild and spoiled us down here.)

PS: Do you know which of the Formula One products exactly? Their site (http://www.formulaone.com/) shows the following, each of which have a Formula One 50 product -- Classic, Comfort, Premier, Ultimate, Pinnacle and UV Shield -- are the variants listed on their site.

The company that installs all of the tinting for my friends and family is called TinT King. They do work for the high end car dealers here in Palm Beach County, but I think they are only located here, NY and ME.

As far as I know, the AM-30 was the only thing on my receipt and I left it up to them to match the other windows. I'm sure there were higher quality films, but I wasn't going to request a material that would not match. Their website is http://www.tintking.com/ . You can contact them for help I'm sure. They may can give you more info on the AM-30 or anything else.

GaryG

Gary,

Thanks for all the tint-related information. My husband corrected me -- his F-150's tint was actually done by our local Ford dealership shortly after he took delivery of it. So, I've got a message in to the dealership explaining my needs and feeling them out in terms of price and availability. It's getting to the point where I either need to buy a whole 'nother sunshade and cut it to fit both the driver's and front passenger's window, or get the tint done ASAP. Hot, hot, sunny, and hot. We got a little rain but in the overnight hours; even with thunderstorms our days are in the unbearably hot and sunny realm now.

If I proceed with this and have good results, I'll post photos. Do you have any photos of your FEH, post-tinting, anywhere? I'd be interested in seeing the overall look it gives the vehicle, even though keeping heat and UV down inside the vehicle (and helping what cool air is inside stay cool longer) is my primary motivation.

Now that I’ve had the challenge of keeping my MPG up and testing the cabin A/C mode, here’s what I’ve found. It is important to keep the battery as cool as I need to be. Driving without cabin A/C and the windows down still puts the battery in a poor operating heat range while trying to max MPG with EV mode. It was hard maintaining 45mpg on my 40 mile commute with the windows down and no cabin A/C. When I used the normal recirc A/C with the windows up, the battery performed better in EV mode which raised my MPG to 47mpg on my commute.

The problem was long stop lights where the ICE was off. At times I needed to use Max A/C which started the ICE to keep the cabin acceptable. Making some adjustments to roads with fewer stops and higher speeds seems to be an answer to parts of my route. A slow acceleration to 43mph allows time the A/C compressor needs to cool the cabin. I play it depending on the cabin temp, how slow of a speed to glide to in EV. Instead of pulsing in EV as much, I’m letting the battery build more of a charge now by kicking on the ICE for the pulse with AC as needed.

The bottom line is, if you want to get the best MPG using EV mode in hot weather, stay cool yourself. The battery will use the A/C compressor even though you don’t. Running the cabin A/C to stay cool, also aids the battery’s performance.

Shannon, I have not taken any pics of my tint job yet. Nothing has ever been used to prevent scratching on any of my vehicle. My GPS did act up two times on my trip to Miami and ask me to make wrong U turns on the freeway. It said I was off road when I wasn’t. It may have been the tint, I just don’t know.

GaryG

Thanks for the update, Gary. Appreciate it! I need to try driving with A/C and windows up more on my daily drives. I've been idly wondering what you've just tested and commented on re: A/C vs. no A/C in our summer heat. I'll do some of my own runs and see if I experience similar results. I'd been driving windows down most of the time but your explanation re: battery optimal operating temp requiring A/C anyway (so why not enjoy it as the driver) makes sense.

Shannan, not running the cabin A/C in 90+ degree weather must be hard on the battery. The Traction Battery Control Module (TBCM) is conservative in demanding the A/C compressor when the cabin A/C is not on. It seems the TBCM or PCM triggers the vent door to be close to the outside if the A/C switch is on in the cabin. This is the only way I can explain why the battery performs better when it's cooler.

Today, from a cold start, I was at 50mpg on my scangauge 20 miles into my commute to downtown WPB. It was 11am when I left so the A/C was on from the beginning. This was not my best for that trip, but keeping that battery cooler when pushing EV really helped. BTW, the battery was at the bottom when I left and 3/4 at the 20 mile drive. Fake shifts were very limited also because most of the time I would pulse up to 43mph, shift to "L" for EV and back to "N" for the glide to ~30mph and hold for a rather short time, and repeat. Since I was not draining the battery completely, I got better MPG during the pulse to 43mph.

Now that I've solve the heat problem and poor battery performance, I'm going to to see if I can match my 70.3mpg RT on Jupiter Island with the A/C on the entire route. Who knows, the battery may perform better during the winter with the cabin A/C on because of how hard and hot it works when pushing EV mode. It could be possible the internal fans don't cool that well pulling outside air from the vents.

Running the A/C like I did today would not be good enough for someone in the back seat. Keeping the fan speed on low helps the condensor stay cool longer while in EV. The cool air goes away fast the higher the fan speed in EV.

Get those window's tinted ASAP!

GaryG

Shannan, not running the cabin A/C in 90+ degree weather must be hard on the battery. The Traction Battery Control Module (TBCM) is conservative in demanding the A/C compressor when the cabin A/C is not on. It seems the TBCM or PCM triggers the vent door to be close to the outside if the A/C switch is on in the cabin. This is the only way I can explain why the battery performs better when it's cooler.I should have noted much of my driving is done in the early morning or late evening hours, so that's how I'm getting away with driving sans A/C on much of the miles I'm driving. When I'm out and about midday or getting into a hot FEH that's been sitting out in sun, I have to run the A/C or I'll spontaneously combust!

I ran my A/C during my drive home yesterday night (9:30 PM) and saw no MPG hit during my 30 minute drive, so I don't know what I've been waiting for! I am usually solo in the vehicle; if I have passengers, I do run A/C and occasionally tick it on to Max. A/C (esp. in bad stop and go traffic). I don't want folks thinking my hybrid can't keep 'em cool, when it's just me being a geek. ;)

I admit being wierd. I bring a bucket of ice water and a dabbing cloth when solo.

Today it is 99 degreese out and +90% humidity. I'd have died (or ran my AC) if I didn't have the ice! :rolleyes:

I usually have an ice cold bottle of water with me when I'm driving around solo during the day. If I know I'll be driving in the heat, I'll swap that for an iced water in an insulated cup.

One other factor I forgot to mention was, I did crank the TP to 55 after reading xcel post. It wasn't much help without the cabin A/C, but it may have played a part in todays commute. So much to learn...

GaryG

Hi All –

This might not be exactly inline with this thread – but as close as I can see without starting a new one.

I don’t know if this anomaly has anything to do with switching to running the A/C, temp change or what. Just wondering if anyone else other than Gary has had the same thing happen?

During a discussion with Gary we were both having the same thing happen – the ICE would not shut down as normal, double-tap, coasting down in L, even coming to a complete stop and – Waiting and Waiting.

I can’t really say that it only happens when running the A/C or even just under normal conditions with the temps going up. I can switch over to the ‘Energy Flow’ screen and there is almost a constant charge to the HV battery – pushing the icon level higher than normal. Also the auxiliary HV battery A/C is running at Max – at least the noise level from the fan/fans is a lot higher. The increase in that level of noise could be contributed to what Gary pointed out, that with the A/C on the air is being pulled from the interior, therefore it would seem to be working harder than usual, because generally that intake sound would be on the outside with the vent door being open to the outside. Kind of like more noise when using outside A/C air and Cabin Recir.

The only solution I have come up with to get the ICE to shut down is to shift to ‘N’ and either using light brake pressure, if at ~40 MPH, or a double-tap if I am going slower, to force the ICE to shut down – but it will shut down in ‘N’.

Anyone else having this problem - any answers as to why or solutions?

Hi Phillip

Let me clarify some things after reviewing the shop manuals.

First, I don't think the HV battery A/C mixes air from the cabin. The Traction Battery Control Module (TBCM) controls an air flow door to the outside. When the Aux A/C for the battery is needed, this door is closed and the system becomes a closed system like the recirc system for the cabin.

The noise you most likely hear is the two fans located within the battery. These fans are variable speed that run 40-100%. When the battery temp is high, the fans work harder and make more noise. The fans can run up to 15 min. after the key is turned off, but will not restart till the key is turned on again. BTW, if the fans go bad, it time for a completely new HV battery unit.

It is vary common for me that the traction motor gets to hot during regen in "L" and will not allow the ICE to shut down with the double-tap in "L" or "D". When this happens, I shift to "N" where there is no regen and tap the brake. This shuts down the ICE most of the time.

The problem I was talking to you on the phone about, was with the battery A/C keeping the ICE running when using the cabin A/C on normal recirc.. I had just put a fast charge in the battery and it was also hot outside. The shift to "N" and tapping the brake had no effect when this happen. Even turning off the cabin A/C, tapping the brakes and using "L" would not allow the ICE to shut down. It appears once the battery needs the A/C, it will not start the ICE, but if the ICE starts for some other reason, it will not let you shut down the ICE till it's cool or you turn the key off. There may be a battery temp that is so high, it does start the ICE if the key is on, but it has not happen to me yet.

Thought that I should repeat what was posted on GH.

GaryG