I had to explain something to my wife, and decided to post my explanation here as well. To many here this is very basic, but there may be some that might find some benefit out of it. Even if it just to show to the wife so they understand.
What happened was this:
When we bought our 320d, I found that when I was using the car, I got around 5,5 – 5,7 l/100km. My wife has a brand new ix35 which she loves, so she only drives the beemer once a week or so. But, as soon as the Mrs. “borrowed” the car, the economy figures would get alarmingly worse. It would go to 6,3 -6,8 in short order.
My first reaction was: “Wow..... she must be driving like a maniac”. Then I started paying closer attention to her driving habits. Yes, she was driving very briskly, obviously exited by the car’s available power. So I thought: “Give it some time, she will get used to it and calm down a bit.” And she did. But, the economy was not much better. Now tends to be around 6,0 – 6,5 l/100km when she is behind the wheel. Yet, on the highway, she sticks to a sedate speed close to the speed-limit (Not at first, but she does now). So, she is obviously not losing it on the highway.
The difference must be in our “in town” driving style. So I focussed more on that aspect. And it quickly became apparent what was happening. She was just not driving efficiently.
The first thing was the most obvious. She was heavy on the foot when accelerating, especially pulling away from stand-still. Next thing is that she does not pay much attention to how she uses the gears. I can sort of understand that, as the diesel's power delivery is so smooth, constant and linear, that the availability of power seems almost endless, even I had trouble in the beginning selecting the most appropriate gear for every situation.
But the most telling factor for me was the use of the brake pedal. She was braking a lot longer and harder than me in spite of the fact that we got from A to B in just about the same time. That is a clear indicator that she is wasting energy. Typical situation, she would pull away briskly from standstill at a robot, gaining on the car in front very quickly, only to have to brake hard for the next robot, etc
That is when I realised one can actually use your use of the brake pedal as an indicator of how efficient your driving style is. Yes, you lose a bit of efficiency when you accelerate hard, but you lose a lot more when you need to just bleed that energy away by braking shortly after. Let me expain:
Situation 1:
As above you accelerate hard for a few seconds just to need to brake hard again ten seconds later, like between robots.
Situation 2:
You accelerate hard onto the on-ramp onto the highway, there is no significant traffic, and you maintain your speed, and need only brake again when you leave the highway.
In both situations you accelerated the same way, but in situation 2, the energy you built up was required in any case to get you up to cruising speed, and was compensated for later when you could just keep cruising at the car’s most efficient speed.
In situation 1, you had to brake, and the energy was dissipated by heat via the brakes, and it served no purpose in getting you from A to B. You did not travel faster, as you had to brake anyway.
So basically what it comes down to in the end, is the old brake pedal. If one is not of the inclination to think too much about the logic of the use of energy, all you really need to do, is watch the use of the brake pedal. If you are stomping on that pedal hard and often you are not driving efficiently, and you are wasting fuel. The more gentle you are on the brakes the more efficiently you are driving, as this means you are not accelerating when it will serve no useful purpose, building up speed, to only waste it again.
Well...to most this would seem very simple and basic to the point of tedium. But here is the surprising thing: “You don’t need to drive like a granny!” You can drive quite briskly if you just do it in such a way that you will not have to brake a lot. And it can be done, quite easily. Just think on it a bit while you are driving, and it will become habit very quickly. You don’t have to be shy about using the beemer’s horses when you want to or need to. Just don’t do it inefficiently. I certainly have no compunction about stomping on the gas when I want to pass a fast lane blocker. The bit of fuel I pay to do that is almost nothing compared to the fuel I would waste in traffic driving inefficiently.
So to sum up, to drive fuel efficiently, you do not need to drive like a granny at all. All you need to do, is drive in such a way as to use the brake pedal as little as possible. And it will have other benefits too. Decrease wear and tear on your tyres, and all the mechanical parts of your car, including the engine.
Maybe some of you can use this to explain this issue to someone in your life who does not understand.
Anyway, thanks for taking the time to read my ramblings.
What happened was this:
When we bought our 320d, I found that when I was using the car, I got around 5,5 – 5,7 l/100km. My wife has a brand new ix35 which she loves, so she only drives the beemer once a week or so. But, as soon as the Mrs. “borrowed” the car, the economy figures would get alarmingly worse. It would go to 6,3 -6,8 in short order.
My first reaction was: “Wow..... she must be driving like a maniac”. Then I started paying closer attention to her driving habits. Yes, she was driving very briskly, obviously exited by the car’s available power. So I thought: “Give it some time, she will get used to it and calm down a bit.” And she did. But, the economy was not much better. Now tends to be around 6,0 – 6,5 l/100km when she is behind the wheel. Yet, on the highway, she sticks to a sedate speed close to the speed-limit (Not at first, but she does now). So, she is obviously not losing it on the highway.
The difference must be in our “in town” driving style. So I focussed more on that aspect. And it quickly became apparent what was happening. She was just not driving efficiently.
The first thing was the most obvious. She was heavy on the foot when accelerating, especially pulling away from stand-still. Next thing is that she does not pay much attention to how she uses the gears. I can sort of understand that, as the diesel's power delivery is so smooth, constant and linear, that the availability of power seems almost endless, even I had trouble in the beginning selecting the most appropriate gear for every situation.
But the most telling factor for me was the use of the brake pedal. She was braking a lot longer and harder than me in spite of the fact that we got from A to B in just about the same time. That is a clear indicator that she is wasting energy. Typical situation, she would pull away briskly from standstill at a robot, gaining on the car in front very quickly, only to have to brake hard for the next robot, etc
That is when I realised one can actually use your use of the brake pedal as an indicator of how efficient your driving style is. Yes, you lose a bit of efficiency when you accelerate hard, but you lose a lot more when you need to just bleed that energy away by braking shortly after. Let me expain:
Situation 1:
As above you accelerate hard for a few seconds just to need to brake hard again ten seconds later, like between robots.
Situation 2:
You accelerate hard onto the on-ramp onto the highway, there is no significant traffic, and you maintain your speed, and need only brake again when you leave the highway.
In both situations you accelerated the same way, but in situation 2, the energy you built up was required in any case to get you up to cruising speed, and was compensated for later when you could just keep cruising at the car’s most efficient speed.
In situation 1, you had to brake, and the energy was dissipated by heat via the brakes, and it served no purpose in getting you from A to B. You did not travel faster, as you had to brake anyway.
So basically what it comes down to in the end, is the old brake pedal. If one is not of the inclination to think too much about the logic of the use of energy, all you really need to do, is watch the use of the brake pedal. If you are stomping on that pedal hard and often you are not driving efficiently, and you are wasting fuel. The more gentle you are on the brakes the more efficiently you are driving, as this means you are not accelerating when it will serve no useful purpose, building up speed, to only waste it again.
Well...to most this would seem very simple and basic to the point of tedium. But here is the surprising thing: “You don’t need to drive like a granny!” You can drive quite briskly if you just do it in such a way that you will not have to brake a lot. And it can be done, quite easily. Just think on it a bit while you are driving, and it will become habit very quickly. You don’t have to be shy about using the beemer’s horses when you want to or need to. Just don’t do it inefficiently. I certainly have no compunction about stomping on the gas when I want to pass a fast lane blocker. The bit of fuel I pay to do that is almost nothing compared to the fuel I would waste in traffic driving inefficiently.
So to sum up, to drive fuel efficiently, you do not need to drive like a granny at all. All you need to do, is drive in such a way as to use the brake pedal as little as possible. And it will have other benefits too. Decrease wear and tear on your tyres, and all the mechanical parts of your car, including the engine.
Maybe some of you can use this to explain this issue to someone in your life who does not understand.
Anyway, thanks for taking the time to read my ramblings.
