Hybrid MPG vs. AZ Heat
 

My wife and I were looking to buy a FEH in the next few weeks, but a question came up about the A/C that I was hoping someone could shed some light on. We have read that the A/C is run on by the engine, and not the battery, which in turn, drops the MPG. Here in Arizona, it isn't an option to leave the AC off. If the MPG for the hybrid drops to the mid to high 20's while running the AC, then what is the benefit as opposed to buying a non-hybrid Ford Escape? Any info or opinions would be greatly appreciated. Thanks!

Re: Hybrid MPG vs. AZ Heat
 

There is a recirculating A/C mode that I use when I need to be cooled. When the engine is running, the A/C compressor runs and generates cold air. When the vehicle cuts off the engine to go to electric power, the compressor shuts down and the fans continue to circulate the cooled air through the cabin. If you are in electric mode for a long period of time, or at a long stoplight, the cabin may get uncomfortably warm (in AZ I'm sure you can count on that). In that case, you can turn the climate control knob to the setting that forces the engine to run so that the compressor keeps generating cold air. Most drivers spend most of their driving time with the engine running, so this is not a big deal. Remember that most vehicles, hybrid or not, suffer some efficiency loss with A/C use.

Let's take the most extreme pessimistic example, where your driving style and environment absolutely demand the A/C is always running, and you are never able to drive in strictly EV mode. The electric motor still assists the gas engine at all speeds, which increases efficiency. Plus, you are recapturing braking energy through the regenerative brakes.

The FEH's 4 cylinder engine uses the Atkinson cycle, which is more efficient than the Otto found in most other engines. Also, the FEH is a very clean vehicle according to the EPA.

Another benefit is that the electric motor can really help you get going quickly. I have never driven a regular four cylinder Escape but I've heard the four cylinder Hybrid more often compared to the V6.

Re: Hybrid MPG vs. AZ Heat
 

I just read my post and thought I should add that the climate controls in the 2008's might be somewhat different than my 2007.

Also, if you were to expect a dip in your MPG during the blazing hot Arizona summer, you can probably expect a MPG boost during the (somewhat) milder winter. Here in Chicago I have the opposite problem- my MPG is much lower in the cold weather than in the warm.

Re: Hybrid MPG vs. AZ Heat
 

I suggest that the 'fuel cost' of operating a vehicle air conditioner in any (good) hybrid will be less than in its conventional counterpart, because its engine is typically operating more efficiently.

And I embrace the FEH as a good hybrid, because its design is very similar to the 2001 Prius I drive :)

DAS

Re: Hybrid MPG vs. AZ Heat
 

Thank you both for your responses. The articles that I have read though, all say that the AC does not impact your MPG in a "normal" gas powered car. I guess that's where my confusion comes from. I honestly haven't seen a difference in my MPG during the summers vs. winters here in AZ, so the report that I read that found with hybrids, the AC running does actually affect the MPG made me a little nervous about my purchase. Thanks again for your responses!

Tim

Re: Hybrid MPG vs. AZ Heat
 

Actually, in almost EVERY car with a belt-driven compressor, using the A/C impacts MPG to some degree.

From ask.com:

On a traditional system, the air conditioning compressor runs off the engine’s accessory belt and draws on the engine; this is why gas mileage drops, because the engine is using additional power to turn another accessory, the A/C.
Cars like 2004 and newer Toyota Prius hybrids use an air conditioning compressor that’s driven by an electric motor rather than the engine’s belt. This eliminates the bad gas mileage factor and any ill effects an engine-driven compressor would have.



I know for a fact that in both my hybrids I have owned (2004 HCH and 2007 TCH) the air conditioner brings down the MPG at least by 1-2 MPG.

Re: Hybrid MPG vs. AZ Heat
 

Actually, in every car, (not almost), using the A/C lowers mpg. The process of running the A/C uses energy which even in a hybrid ultimately comes from the fuel burned. The energy used to run the A/C is not used to move the vehicle. Therefore, all other things being equal, the mpg goes down.

However, the complex situation of windows up/windows down, differences in temperature, driving habits, vehicle size and horsepower, speed travelled, sunlight, on and on and on make understanding the best solution for maximum efficiency in every case very difficult.

If I lived in AZ my A/C would be on most of the year. Being hot and miserable is not worth the usually modest efficiency lost to me.