Posts Tagged ‘[lang_en]Hypermiling[/lang_en][lang_fr]Hyper-kilometrage[/lang_fr]’

Free Petrol? Free Pizza!

Saturday, January 2nd, 2010

At the end of 2008, I explained how changing my driving habits had effectively given me free petrol for the month of December. Time to review the figures for 2009!

In 2008, my car travelled 10400 km, using 621 litres of petrol. That works out at 47.3 mpg if you’re British, 39.3 mpg if you’re American, and 6.0 litres per 100 km if you’re French. In 2009, the same car travelled 9440 km on 552 litres. I’ll let you do the math, but by my calculation that’s about 2% better on the mileage. More importantly, the total fuel consumption went down by 11%, which is quite a chunk. The difference is worth about $100 (70 euros), enough for another good meal out with Dweezeljazz.

Free pizza for driving less, I can handle that!

According to the 538 blog, the average American family of 4 uses about 2000 US gallons of petrol per year. That’s over 7500 litres. Imagine how many free pizzas they could get if they saved 10% of that?

I’ve also been following my electricity consumption for the past year, and have found that we average about 30 kWh per day. According to Wikipedia’s list of electricity consumption per country, we’re a fair bit lower than the average for France, which would be 40 kWh/day for the two of us. Not bad at all.

I only monitor our electricity use by reading the meter once per week, but that’s enough to start getting useful information on where it all goes. For example, our water-heater broke down in summer, allowing me to estimate how much goes into heating water for us. Some people go much further. Tom Harrison uses a TED 5000, a gadget that can show electricity use by the second as it happens. That’s how he found out that his gas oven uses 300W of electricity. How many people would even guess that a gas oven uses electricity, never mind as much as that?

If you’re interested in checking your own use of resources such as petrol and electricity, there are a number of ways of going about it. You can get an idea of your petrol use by looking at the service-records for your car, the total number of miles on the clock is typically recorded there. If you know how often you fill up your petrol tank (credit-card receipts, perhaps?) you can get a fair estimate of your mileage that way. For electricity or gas, you can look at your bills over the last year to get a starting point (make sure they’re actual readings, not estimates).

Once you know how much you’ve been using in the past, you have a good incentive to reduce it in the future. You can compare your petrol consumption with others by recording your results at My Astra is there.

link to 10:10 websiteIf you’re serious about wanting to reduce your consumption, why not sign up with the 10:10 campaign (there’s a separate link for people in the UK). The 10:10 campaign wants people, businesses, and other organisations to reduce their carbon footprint by 10% in 2010. That’s a modest but significant goal which is easy to achieve, and is intended to focus on actually doing the things that are needed, rather than just talking about them. Over 50,000 people have signed up so far, including Pete Postlethwaite, star of the Age of Stupid film.

It has to be said, the 10:10 website is not very well laid out. It took me ages to find the 10:10 blog, for example. They’re looking for a web developer if you’re interested in helping them improve it. You can actually get a better idea of what it’s about from the Wikipedia 10:10 page, which also lists some of the people and organisations that have comitted themselves to action. They include the British cabinet, the Science Museum, Microsoft UK, the Guardian, and a whole bunch of celebrities. I’ll be checking there again in a few days to see if they’ve added my name to the list.

The Guardian are throwing a lot of their weight behind the 10:10 campaign. It’s worth reading their articles by Andrew Simms, Chris Goodall and Ian Katz, among others. I’m convinced 10:10 is worth doing, so I signed up. After all, you can look at it differently, and just think of it as free pizza.

Heatwaves, Pollution, and Money to Burn

Saturday, August 22nd, 2009

heatwave in France

heatwave in France

France is just coming out of a heatwave at the moment. Whenever I think of a heatwave, two things come to mind. The first is the film ‘Grumpy Old Men‘, with Jack lemmon and Walther Matthau. The film starts with the classic Irving Berlin song “We’re having a heatwave”, while they’re bundled up against the snow and ice. We were singing that a lot this winter.

The second thing that comes to mind is the heatwave of 2003, though that was far worse than this one. That one killed tens of thousands of people across Europe, I’m not sure this one has caused any extra deaths yet?

Even if it’s not as strong as the one six years ago, this has still been an unpleasantly hot time. A large part of the south of France has been under yellow or orange alert, meaning that people have been advised to take extra precautions against the heat. Things like staying out of the sun, drinking plenty of water, avoiding strenuous activity in the hotter part of the day. I’ve been playing it safe, and avoiding exerting myself altogether. The only exception has been to water the plants on the terrace. Come to think of it, that’s been hard work, they have needed a lot of water every day this past week!

Several measures were imposed in France to help people cope with the heatwave, from the small-scale to industrial. In some areas, exterior painting with solvent-based paints, and use of petrol-driven garden equipment was banned, while the heatwave ran its course. Industries were told to reduce the amount of pollution they produce, and car-drivers were ordered to reduce speed by 20 mph on major roads, for the same reason. Since the pollution from these sources is made worse by the strong sunlight, this is particularly important at times like this.

Geneva suburbs under smog

Geneva suburbs under smog

The same suburbs on a clear day

The same suburbs on a clear day

But what about when it isn’t so hot? Doesn’t pollution from all these sources matter then? It might be worse in a heatwave, but pollution from cars is dangerous at any time. What if people drove slower all the time, so they always produced less pollution? That’s something easy that we can all do. You can reduce your own contribution to pollution quite a bit that way, and save yourself some money in the process.

Last summer, when petrol prices were high, drivers in France reduced their consumption by 15%. Curiously, that drop in petrol consumption continued into September, even after the price of of petrol came back down again. I don’t know if that trend continues today, I hope so, but I haven’t been able to find out anything.

I know from my own experience that you can save a lot of your fuel costs just by driving gently, and anticipating changes in the traffic around you. My car is 18 years old, but I get on average 48 MPG (UK gallons, that’s 40 MPG in US gallons, or 5.90 l/100km) by driving gently. According to the US government, that’s almost the same as a 2009 Honda Civic Hybrid.

I track my fuel consumption at, you can find me there among the Opel Astras. Fuelly is very easy to use, whenever you fill your petrol tank you just note the mileage, date, and amount of fuel, then enter it into fuelly and it does the maths for you. It’s a great way to see how much petrol you really are using, and to compare yourself with other people. I can see there that, compared to Honda Civic Hybrids that people have registered, I actually get better mileage than one third of them. That’s not bad for such an old car!

You might think that it’s not worth much effort conserving petrol in an old car, but that’s not true. It’s actually easier to make good gains from an older car than from a newer one. Why? Because MPG is a deceptive quantity, and it’s more instructive to think about the amount of petrol it takes to travel a given distance (Gallons Per Mile, or GPM), instead. The more petrol you use to start with, the easier it is to improve, so drivers of older cars can make bigger gains.

For example, if your car does 20 MPG, you need 5 gallons of petrol to travel 100 miles. If you can improve your mileage by 5 MPG, to 25 MPG, you need only 4 gallons of petrol to travel that same 100 miles. You save one gallon. If your car did 40 MPG instead, you would have needed only 2.5 gallons to travel that same 100 miles in the first place. To make a saving of one gallon with that car, you would have to improve your mileage to 67 MPG, an increase of 27 MPG, not 5. Small savings on high-consumption make a big difference.

That’s not to say you shouldn’t buy an economical car if you can afford it, certainly you should. But if you can’t afford to replace your old banger, you can avoid wasting a lot of money just by paying attention to the way you drive. Why don’t you try it, you might enjoy it? Unless you have money to burn, reducing petrol consumption is a winner all round.

Free Petrol in December

Thursday, December 11th, 2008
Cherry Tree by Steps
Cherry Tree by Steps

I get free petrol this month. In fact, I expect to get free petrol every December from now on. I didn’t win the lottery, and I don’t have a company car, so how do I manage it?

About a year ago I read some articles on the web about how driving differently can reduce petrol consumption, with all the benefits that entails. I hadn’t thought about it much until then, but I decided to give it a go. Now I find I can travel about 8 or 9% further than before for the same amount of petrol.

That may not sound like a lot, but one month is 8.3% of a year, so as I see it, my petrol is free this month. I think I’ll use some of the money to take Dweezeljazz out to dinner.

There are several pages on the web now that discuss driving economically. There’s one from the BBC which has a graph of CO2 emissions versus speed. It shows that the most fuel-efficient speeds for driving are about 35-50 mph (60-80 kph).

Sheep and Trees
Sheep and Trees

There’s a more detailed BBC article and an an article in French that discuss the same topic. Between them, they make a number of suggestions

  • drive smoothly, accelerating and braking gently
  • remove the roof-rack and any excess weight
  • check your tyre pressure
  • change your air filter regularly
  • don’t leave the engine idling unnecessarily
  • change gear early, maintain constant speeds when possible
  • use engine-braking rather than your foot. Modern cars will reduce the petrol injection when engine-braking
  • opening the windows or using the air-conditioning will increase consumption
  • know your route, to avoid unnecessary use of the car
  • avoid unnecessary trips, especially short ones which don’t give the engine time to warm up
Cherry Blossom On Steps
Cherry Blossom On Steps

Driving economically not only saves petrol, it also reduces wear and tear on the car in general. It reduces your emissions of greenhouse-gasses and other pollutants, and makes the roads safer for pedestrians and other road-users.

Driving economically is one thing, but the last two points in the list above address the issue from a different perspective, consuming less petrol by avoiding use of the car. There are other ways to do that too, such as car-pooling, or sharing a shopping trip with a friend or neighbour. If you work flexible hours you may be able to adopt a schedule that avoids you getting caught in rush-hour traffic.


There’s another way to save petrol with the car, that’s to not drive it all the way to where you’re going. Instead of driving to my office, I now park my car over a kilometre away and walk the rest of the distance. It adds 15 minutes to my journey, but I get a lot of good exercise in the process. Getting that exercise by other means would undoubtedly take more time than that out of my day. Instead of just walking along the road, I have a route from the car to the office which avoids traffic, so I’m not breathing so much vehicle pollution. It’s not flat either, so I get even more exercise from the steps I climb up and down every day.

Tree in Autumn
Tree in Autumn

It’s actually a very pleasant walk, I get to see many interesting things on the way. All the photographs in this post were taken on that walk at one time or another. I get to see things like this daily, but I wouldn’t see them at all if I simply drove all the way to my office.

According to the BBC, driving economically can reduce petrol consumption by 10-15%. Apparently, Ford themselves believe people could reduce their consumption by up to 25%. I know I could try harder, and maybe, if I do, I will have free petrol earlier next year.

I’d like that, Dweezeljazz and I know a number of good restaurants nearby.