Yes, sometimes it appears we just can't have enough of this topic:

Hybrids Can Still Give Good Mileage In the Heat


As many of us have found out (especially on HCH-II's & Priuses): Manage thy State of Charge wisely.




Cheers;

 

The TCH uses an electric compressor and I keep it in ECO mode all the time. A couple of times I performed a highly unscientific experiment. While on the highway with the A/C on I drove until the SOC was fairly high to eliminate any differences due to recharging the battery. I drove several more miles like that and then turned off the A/C. Judging by the instantaneous mpg gauge my mileage definitely takes a hit with the A/C on. Also, turning off the A/C I can stay in EV mode at a higher speed and my SOC does not drop nearly as quick.

With that said it was only an experiment. I'll suffer the loss of several mpg to stay comfortable.

 

I don't know for sure but I think the potency of the engine has something to do with it. In my insight, putting the a/c on is a deathblow for my mpg. However, in my HCH it doesn't make nearly as much of a difference. Thats anecdotal obviously but seems to make sense IMHO

 

I have to say that I will use the air conditioner when it is hot outside. I purchased the hybrid to save, or not have to spend as much on gas.



I recently took a trip from Virginia to New Jersey using the air conditioner (set at 78), drove at 73mph, which included bumper to bumper traffic 4 times during the round trip and still averaged 47.75mpg.



What I found to be a big benefit was running the A/C, staying comfortable while the car was in auto stop. (Engine shut off)

 

I would think you would run into problems driving 73 mph in bumper to bumper traffic.

 

This is a major point. An AC that uses up only 4% of the engine power on a normal vehicle may be more like 6-7% of total engine power on a scaled-down hybrid engine. The same amount of fuel consumption (say 0.2 gallons an hour to cool the car) would be a higher percentage on the more efficient hybrid -- the relevant figure is the gallons per hour of air conditioning (not miles -- more fuel will be spent running AC by driving slower), but few people will ever look at that.

Using the elecrtic however does offer the advantage of strategic load balancing -- running off the engine more on period of lower load, and running off the elecrtic motor when more engine power is needed. There are many automatic algorthims that could be implemented, even on the older belt-only AC systems, that would spread out the AC load based on engine load, but they have largely not been implemented.

 

True, it would be nice if we had some Speed Racer functions on our cars to avoid those type of situations and hard braking while reducing the speed from 73 to 0 didn’t help with the gas mileage either.

 

You can reduce the load induced by any belt-driven AC compressor by manually cycling it off while the engine is in a heavy load condition such as accelerating or climbing hills. Turn it on while at cruising speed, going downhill or slowing down and the MPG loss becomes manageable.

-Steve

 

First there was no A/C. Then it was a luxury on cars, then an option. Now it's pretty much standard across the board. What, oh what did people do before there was air conditioning? I guess the same thing I do - roll the windows down.

 

And my grandmother used to use a scrub board to do her laundry. But then something better came along. If anyone told their wife to do the same thing that was done before washing machines he'd be sleeping on the sofa for a long time.

Just because things used to be done a certain way, doesn't mean it's better. I'll give up 2 mpg to be comfortable. Aside from which opening the windows doesn't do much for the aerodynamics.