4 Gas Saving Myths

Wow, Three whole dollars per tank to be comfortable? It is is certainly a question of priorities and my comfort is worth $3 every tank of the year.

 

If you have the windows down while driving and drawing in cooler air, woudn't that create a good cooling effect for the for the traction battery? I have read posts about having the AC on as a beneficial effect for the traction battery. I would think drawing in air flow into the cabin while the windows are open would also work in the same manner. Thought!!!

 

No such thing as "cooler air" in S FL. It's 80 deg at 6:30 AM It only goes up until the afternoon rain or steam bath evaporates and keeps it in check around 90 deg.

 

The Prius AC runs on electricity and is not driven by a belt that the engine powers. I have sat in 85 degree weather parked with the AC on low on batery power for several minutes before the engine came back on and then it was on for only a minute or so. Bottom line is that if you use the A/C on moderate to low the impact on mileage is hardly noticeable, especially if the car is moving. But I would not shut it off at stop lights the engine will still shut down while the A/C runs on battery power for a few minutes.

 

Ah yes, somehow I managed to skip over that comment from Delta Flyer while reading through this thread.

As cnschult points out, shutting off the A/C while accelerating and on while decelerating doesn't make sense in a Prius. There is typically no change in available HP whether the A/C is running or not. However, when decelerating (especially while braking), the Internal Combustion Engine (ICE) frequently will turn off to save fuel. If you turn the A/C on, the additional electric load might convince the car to keep the ICE running, thereby using more fuel.

If you are going to shut the A/C off and on with changes in speed, you should do it the other way around. Turn it on when accelerating since the ICE will be on anyhow, and turn it off when decelerating so the vehicle can shut the ICE off if it wants to.

 

I am an A/C Nazi, but in the dead heat of the summer I will turn it on because there is nothing more that I hate than arriving to my destination with a wet back of my t-shirt. Especially now that I must think about the battery I will keep the cabin cooler. I do like to drive with the windows down but that is on back country roads not highways. I can't hear my music if I have them down on the highway.

 

What makes you think there is no freon in the Prius? It uses one of the freons (non-CFC type). Or is this a joke I don't get?

 

Keep in mind that the article is for general automobiles and doesn't target the Prius. Consider how often when the ICE is running that it is not only powering the drivetrain, but also charging the batter or powering the electric moter or both!

Seems in a regular gas vehicle that there is probabl a lot of wasted energy which would easily go to power the A/C. So while A/C usage might be a "gas saving myth" on regular cars, its not the same on hybrids, specifically when they are running on electric.

 

All the real Freons are CFC. Freon is a DuPont trade name for its CFC refrigerants.

The Prius uses R-134a refrigerant, a tetrafluoroethane. This is non-CFC and as such is not a Freon. It has, however, at times been inaccurately referred to as "Freon 134a"