The mountain mode is rarely used. It acts to cause the range extender turn on at higher charge point of the battery. This allows a deeper battery reserve for use when travelling up a long steep grade. In nearly 2000 miles of driving I have never found the need to use it.
When the car is powered on it is in regular mode by default. This provides a standard accelerator experience. Pressing the drive mode button twice causes the car to shift into sports mode. Once engaged the driver will feel the car surge forward, and it becomes much more spirited in acceleration.
GM Volt director Tony Posawatz once mentioned that the car would get the same efficiency or EV range whether the driver was in sports mode or regular mode. Top power out put is the same 110 kw, and flooring the pedal produces the same response in both instances.
“On the various EPA federal test procedure cycles, the efficiencies are basically the same, says Posawatz.
It is true, though that driver behavior is a more prominent factor. Aggressive use of the accelerator in sports mode will lead to more range reduction than the same use of the accelerator in normal mode.
“Sport mode may cause you to have a bit more fun and if you fully realize the fun opportunities, you will be a bit less efficient,” says Posawatz.
In my experience driving the car, I tend to prefer sports mode, and use it all the time. Tony Posawatz also drives a captured test fleet Volt and uses it a bit differently.
“I have found that I use Sport mode and have fun when I know that I will make it to my charging station without using gas and with time to charge,” he said. “It is my guilty pleasure.”
“Similarly, I have changed my driving a bit to see if I can beat the “video game” and improve my numbers,” he added.
Braking is another issue.
When in D mode, the car softly coasts similarly to a conventional car when the foot is off the accelerator. L mode engages a strong regenerative drag when the foot is off the accelerator that allows the driver to simulate a downshift effect and get motor braking, sparing the disc brakes from wear.
It has been my preference to drive at speed in D mode, but when needing to slow or in stop and go traffic I use the L mode.
Posawatz explains that overall efficiency doesn’t differ much between these two settings either.
“Relative to D vs. L, there also is not a lot of difference in efficiency between the two,” he said. “Going down Pikes Peak, you want to be in L.”
“You want to use the coast of drive and then shift into L as you approach a stop, he added. “I use the L a lot because it is a more engaging drive, especially in Sport and on winding roads.”
This entry was posted on Monday, December 13th, 2010 at 8:01 am and is filed under Efficiency, Features, Performance. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.