Hi Brian,
If it were only that simple!
What you have done is a common misunderstanding of the range number on the display.
Let us say that you have charged overnight and your car is 100% charged. It might read 45 miles EV range on the display. That 45 miles is an estimate of how far your current charge would take you if all the conditions were the same as when you last drove the car. The terrain, the temperature, the traffic conditions, the speed... everything. Of course each time you get in the car and drive the route is different or the traffic conditions are different or your speed is different. So that estimate can only be considered that... an estimate.
Now, when you drive around and that estimate drops it is because you are using power and also because the conditions on this drive are not as favourable as the last one. Of course, if on this drive traffic conditions etc allow you to do more regen then the estimate will drop more slowly, true, but you cannot say that the difference between what the estimate indicates and what you drive is from regen.
Drive the car hard for a few miles and that estimate drops. Then drive it more gently and it go up. In fact it is even more complex than that because it isn't just your last drive that it uses to calculate the estimate. It is a rolling 100-150 miles. So that might mean your last few drives. So drive it hard for 100 miles or so and all your estimates for the next 100 miles or so will be lower than you might expect.
There is no way to actually quantify how much benefit we are getting from regen.
What is also little understood is that using regen is not the best way to get maximum range. Regen converts some of the kinetic energy built up in the car through accelerating and while going down hills into chemical energy in the battery. That is great. Cars without regen (all normal ICEs) just loose that energy as heat when they brake wasting it. We can use regen and recover some of it and put it back into the battery.
However, it is a fact of physics that energy is lost when converting from one type to another (in this case kinetic to chemical) and so regen is not efficient at that conversion. By far the best way to conserve energy is either not build it up in the first place (drive more sedately and more slowly when appropriate and safe to do so) or, when slowing down not to use regen at all and to let the car slow down on its own. That way there is no conversion in the regen process and less energy is wasted.
What does this mean to us Ampera drivers? Well, for most people that really aren't concerned about getting the extra mile of range it means nothing. You can drive the car just like any other car and the regen system will allow you to recover much of the potentially wasted energy when you slow. Just use regen to slow the car through good driving habits and anticipation and you will get good range. However, if you really want to get more range then the technique is to try to avoid using regen OR the brakes. Accelerate sedately, keep speed down to 40-50 when safe to do so, anticipate slowing down well in advance and by leaving the car in D instead of L you will get less regen and less energy wasted.
So, I seem to have contradicted what Vauxhall and what most people say here haven't I? Vauxhall say L will give you more regen and so better range. I am saying for best range us D not L. Wierd eh? Well not really. We are both right in a way.
Remember, the car is designed for normal people doing normal driving... not geeks like me that want to get the extra mile of battery range. For the vast majority of people, people that don't want to use this "hypermiling" technique, they will get more range from using L than D. They will then be using more regen and be saving more energy instead of wasting it through using the mechanical brakes. However, the geeks amongst us (like me
) love to play with the technology and see what we can do with it and if you count yourself as one of those then to get the best range drive in D and drive with so much anticipation and care that you don't use regen and waste that last ounce of energy!
Of course, the great thing about the Ampera is no one needs to hypermile drive. With the petrol generator we just drive as and when we want to and if I get a mile or two of EV range more or less than you it doesn't matter a jot except financially and even then it is pennies at max. In the Nissan Leaf however hypermiling is a great skill to have as it could potentially make the difference of me arriving at my destination or not :shock: :shock:
Happy hypermiling.