Oman Posted June 26, 2009 Share Posted June 26, 2009 I have been taking mileage measurements on two 34 mile legs of my commute. The mileage varies on each direction so they have been compared separately. The legs consist of 70% (mileage wise) 70Mph HWY and 30% 40-55Mhp county roads. The average mileage with no A/C and windows completely closed (average temperature 72degree for the sample period) - 37.2 MPG The average mileage with driver and passenger windows partially open (about 1-2 inches, 75degree average for the sample period) - 36.1 MPG The average mileage with A/C keeping the cabin at 74degrees (92 degree average temperature) - 34.1 MPG I did get one leg at 31MPG! The outside temp was 98degrees and the car starting temp was 108degrees. It was very humid too. I think the fan stayed at max the whole time. When I stopped in the garage the car dumped about 2 gallons of water on the ground from the evaporator drains. I have noticed that unlike the standard mechanically linked compressors, the FFH appears to be able to vary the power sent to the compressor. Most vehicles have a clutch that continuously engages and disengages the compressor. In the FFH it seems that the current draw with the A/C on will vary from about 15% of the power graph to nearly 75% of the power graph. I would expect some difference as the evaporator and condenser fans vary their speed but the significant change in current seems to me to mean that the compressor itself can vary its power demands. I have found that rolling down the windows all the way for the first couple of miles (letting the cabin cool as much as it can) and then closing them with the A/C set at around 75 and setting recirculated air provides good comfort and good mileage. In my truck running the A/C did not make any measurable difference in mileage. That's what happens when you only get 14-15 MPG to start with. Jon 0 Quote Link to comment Share on other sites More sharing options...
lrymal Posted June 26, 2009 Share Posted June 26, 2009 I live in East Texas, hot humid East Texas (85% humidity at 100 degrees). I will happily trade 4 - 5 MPG to stay cool, if it is even that much. I think the FFH does a marvelous job at balancing this stuff and am happy to no longer be at the mercy of a belt-powered compressor clutch. I was surprised, though, when sitting in construction with this humidity/temperature, that the car's interior was very cool, and I was on battery for the entire stoppage. ICE never kicked in. 0 Quote Link to comment Share on other sites More sharing options...
tonifan Posted July 6, 2009 Share Posted July 6, 2009 Oman: Remember that the 2010 FFH does not have a separate air conditioner for the battery, unlike most all other hybrids. The battery generates heat on all hybrids, regardless whether they're true hybrids or half-hybrids. The 2010 FFH cools its battery with the cabin air, keeping the battery cool. This means less weight because of not having the extra air conditioner and thus better gas mileage. This might explain the difference between the 41 city rating for the 2010 FFH and the 38 city rating for the Toyota Camry. Hope this info helps. I'm fairly certain of the mileage numbers, but you may want to check for yourself. I just got my 2010 FFH on July 4 (what a celebration!) and by the time I got home, the little bush indicator on the dash was smothered in green leaves, and my combined mileage (city and highway) was exactly 40.0! 0 Quote Link to comment Share on other sites More sharing options...
akirby Posted July 7, 2009 Share Posted July 7, 2009 This might explain the difference between the 41 city rating for the 2010 FFH and the 38 city rating for the Toyota Camry. The Camry is rated 33 in the city, not 38. 0 Quote Link to comment Share on other sites More sharing options...
rfruth Posted July 7, 2009 Share Posted July 7, 2009 According to cars.com the 2010 Camry hybrid gets 33/34/34 - does the traction battery have it's own a/c or like the Prius & FFH a fan that uses the cabin air to cool the battery ? 0 Quote Link to comment Share on other sites More sharing options...
tonifan Posted July 13, 2009 Share Posted July 13, 2009 Remember, with the Ford Fusion Hybrid, the cabin temperature is what regulates how cool or warm the battery is. In most all other manufacturers' hybrids, both full- and half-hybrids, the battery pack actually has a SEPARATE air conditioner, or cooling unit, just for the battery. Ford's version uses the ambient passenger compartment temperature to keep the battery cool. So, the warmer the cabin temperature, the warmer the battery will run, and perhaps, at higher temparatures, would make the city-highway mileage suffer. Any thoughts? 0 Quote Link to comment Share on other sites More sharing options...
Oman Posted July 14, 2009 Author Share Posted July 14, 2009 They actually designed the cells in the pack to be able to withstand higher temperatures which is why it doesn't need separate A/C. Higher temperatures actually increase the batteries ability to store and release a charge, that is until the chemistry starts to break down. Considering the cost of the battery pack and the fact that it has a substantial warranty seems to indicate to me that Ford has tested the cells well passed the point where you and I would be keeling over in the cabin before the cells would be damaged at the same temperature. There is a pretty hefty fan under the back seats (seems to be variable speed) that moves cabin air over the pack. What I am more curious about is how much our mileage will go down in the Winter. Cold cells can't charge as effectively so much of the reclaimed energy will be lost until the pack warms up. I think this is where the FFH will also vary quite a bit from the Prius... Since the cabin air is used to cool/heat the pack there is an advantage to using the ICE to heat the cabin. With the Prius there was only a mileage disadvantage to using cabin heat so some folks would not use the cabin heat (I don't care THAT much about mileage - it gets darn cold in Minnesota and I purchased an FFH to be comfortable on my commute) I wonder if in the Winter the FFH might actually beat the Prius? The two Prius owners here at the office both have stated that Winter mileage can go down below 40MPH. Jon Remember, with the Ford Fusion Hybrid, the cabin temperature is what regulates how cool or warm the battery is. In most all other manufacturers' hybrids, both full- and half-hybrids, the battery pack actually has a SEPARATE air conditioner, or cooling unit, just for the battery. Ford's version uses the ambient passenger compartment temperature to keep the battery cool. So, the warmer the cabin temperature, the warmer the battery will run, and perhaps, at higher temparatures, would make the city-highway mileage suffer. Any thoughts? 0 Quote Link to comment Share on other sites More sharing options...
svjim Posted July 16, 2009 Share Posted July 16, 2009 I wonder if in the Winter the FFH might actually beat the Prius? The two Prius owners here at the office both have stated that Winter mileage can go down below 40MPH. Jon Not only does the mileage go down in the winter, the Prius has some sort of rubber bladder in the gas tank that stiffens in the winter and it cannot hold a full tank. I lived in Minneapolis for about 4 years, so I know what the winters are like. I would look at some of the early blogs on the FFH. It seemed like most of them were from the midwest and they test drove the FFH in Feb and March and were not overly impressed with the MPG. They all sort of noted that it was winter time and thought that winter may effect the mileage but didn't say much more then that. Jim 0 Quote Link to comment Share on other sites More sharing options...
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