Klaus Schmolls recent article here on oppo really hit a cord with me. About a month ago I started to make a real effort to maximize my fuel efficiency. I try and outdo myself every day and the reason I do it is purely because fuel is so expensive here in the UK. Klaus is paying 1.50 Euros per liter of fuel, but here it spiked (although it has eased a little bit recently) to 1.72 Euros per liter of diesel.
There is another reason as well. I'm lucky enough to have a company car, but every-time we buy fuel we have to buy it on a fuel card. At the end of each month the company subtracts the amount of business miles we've done from the total and asks us for a check for the remainder, i.e. our personal mileage. That means we have to pay for last months fuel in one lump sum, and it's a painful amount of money to part with in one go.
When I chose my car I went for the new Audi A3. There are a lot of reasons but a major one was the rated fuel economy of 68.9 MPG. Car companies are notorious for giving mpgs that you can never achieve, so I thought I might be able to get 60 or so on my way to work. In reality, driving in my usual way I was only able to achieve around 50MPG, so I was quite disappointed. However, after changing the way I drive and learning a few tricks on the way, Ive managed to get a staggering 67.4 mpg.
And this is what you need to know:
1) Cold engines are inefficient. The oil in the engine is also cold and as such it is very viscous. This doesn't mean you should warm it up before you drive though as that would waste fuel. Keep the revs low and drive it straight away. It means that any short journeys are going to be bad for the wallet. (Do you really need to drive??) It also means you won't start getting good mileage until about 30 mins into the journey.
2) Accelerate as smoothly and slowly as you can. Ok, 'who got time fo' dat?' My saviour in this area is the Audi's cruise control. The last 5MPH before it reaches the set speed is accelerated at very slowly, and being a machine it has infinite patience, so I just set it to accelerate in 5 MPH intervals.
3) Decelerate slowly and without using the *brake where possible. Row through the gears as you decelerate and keep the revs low to keep the engine braking to a minimum. This does require patience and long deceleration periods, but this is where the BIG gains are made. Modern injector type engines use 0, (that's ZERO) fuel while engine braking, so keeping this deceleration period as long as you can is key.
*Please use the brake where necessary and drive safe!
4) Keep to a reasonable top speed. To be honest, my new rule is to keep to the UK's 70MPH limit. Although it's unlikely you'll be stopped at 80 on the motorway, the fuel economy is atrocious. Even at 75 it's bad, 70 is acceptable and 65 is good. If you have an on-board computer that tells you the instant mileage you can work out which is best for you.
5) Going uphill uses a lot more fuel than normal, but if you can cruise downhill without touching the accelerator you'll get it all back AND MORE on the other side.
Now I easily get 55MPG and 60 is achievable on most jouneys. It also means I'm about $75 dollars a month better off. And Klaus, to answer your question, this is where all money saved goes: