GREENer HOUSE

95 right? More likely wrong.

The conversation after Sunday lunch somehow migrated to the topic of octane in petrol. A woman was complaining that her husband makes her buy premium 95 petrol even though it costs more. The husband, who drives a Prius, was defending the extra expense on the grounds that the extra octane makes the engine run more efficiently, reducing carbon dioxide emissions.

I had never heard this before, and any idea that might reduce C0₂ emissions catches my ear. Was I unwittingly damaging the atmosphere by my frugal habit of buying the cheaper petrol? I had to look into this.

One of the best sources of information available was an Engen FAQ on octane, which confirmed, as I had suspected, that we cheapskates are right. “The great majority of vehicles inland . . .  are satisfied by 93 octane,” the website explains. “The use of octane grades higher than your vehicle actually requires will cost you more, cost the country more and have a negative environmental impact.”

The FAQ explains that this is because:

“There will be no additional benefit to driveability or performance of your vehicle if you use a higher grade than it requires. Petrol with a higher octane requires more severe refining and greater energy use in the production process. If not offset by greater fuel efficiency of the vehicle using the fuel, this extra energy use is wasted energy. This wastage results in higher emissions of greenhouse gas (carbon dioxide), which harm our environment.”

What the Engen website did not explain is the relationship between octane and altitude. Octane is purely a measure of how petrol reacts to pressure. Higher octane fuels will not ignite prematurely under higher pressure, which could cause engine knocking. But the Highveld altitude has a low ambient air pressure, which reduces the pressure inside most engines and thus reduces the need for octane. I spoke to John Fitton, an independent petroleum industry consultant, who said that most engines requiring 95 octane at the coast—as is recommended in the manual for my Honda Jazz—only need 91 octane in the Highveld.

South African regulations allow for three grades: 91, 93 and 95. At low altitude, 95 is the only grade available. Highveld petrol stations offer 93 and 95, but 91 isn’t sold at all in South Africa. Fitton told me that this is only because the petrol retailers are trying to satsify ill-informed customers. “Consumers think octane is power,” he said.

Fitton pointed out that the lower octane requirements at higher altitude do not apply to turbocharged engines and a minority of newer engines with gasoline direct injection. (These engines are sold under a variety of brand names such as Mercedes-Benz’s Charged Gasoline Injection, VW’s FSI and Ford’s EcoBoost.) Owners of these cars should obey the instructions in the car manual whether they are in Lesotho or Lambert’s Bay. For the rest, Fitton said, “There’s no advantage to using the higher octane; you’re just going to spend more money and emit more C0₂.”

Since this blog is dedicated to finding everyday solutions for environmentally-concerned South Africans, I don’t usually stray into political issues. But my comments on the new carbon tax on automobiles, which appear in the latest issue of The Star Motoring, are relevant to the decisions car buyers make. Starting in September, the government will be adding a tax to any car that emits more that 120 grams of carbon dioxide per kilometre.

At 75 rand per gram above 120 g/km, the tax can add up. So check the website of the National Association of Automobile Manufacturers of South Africa for the carbon emission of the vehicles on your list before you head to the showroom. Despite the howls of protestation from the auto industry, I found a surprising number of cars that will attract no tax. Here’s the list:

Audi A4 2.0 TDi 100kW, Citroen C1 1.0i and C3 1.6 HDi, Daihatsu Charade 1.0, Fiat 500 1.2, Ford Fiesta 1.6 DV6, Honda CR-Z  Hybrid, (as well as the anticipated hybrid Jazz), Peugeot 107 and 207 1.6 HDi, Smart fortwo, Toyota Prius (the cleanest of the lot) and the VW Golf 6 1.6 TDi, Polo 1.6 TDi, and CrossPolo 1.6 TDi. BMW’s 320d Dsl comes so close to the mark that the tax will have no noticeable impact on the sticker price.

And in case you missed the latest Star Motoring, here are my thoughts on the tax:

The “debate” over the carbon tax on new cars is hardly a debate at all. The Retail Motor Industry’s opposition to a tax based on vehicle carbon dioxide emissions receives plenty of publicity, and the government fails to rise to the defense of the new tax, due to be implemented in September.

But there are plenty of good arguments for taxing CO₂ in the car showroom that are not being heard. The decision made at the point of sale is a fateful one, and not just for the new owner of the car. Should the buyer naively choose a thirsty vehicle without calculating the lifetime fuel costs in advance—a common occurrence—the environment will lose regardless of what happens after he drives away from the dealer.

We do not live in Japan. Cars do not head for the scrapheap after 100,000 kms. They are passed down the economic ladder to poorer and poorer drivers until they literally fall apart. So if the new owner of this vehicle suddenly turns green or tires of paying dearly at the pump, he will sell it on to someone else to do the polluting for him.

Similarly, if he decides to drive less to compensate for his fuelish vehicle—the alternative suggested by the motor industry—the car will last longer. He may be delaying its ultimate output of CO₂, but if the car will last 300,000 kms and emits 200 grams of CO₂ per kilometre, it will eventually send 60 tons of carbon dioxide into the atmosphere.

If, however, the new tax prods him to save R5250 by purchasing a vehicle that emits 130 grams/km instead, the planet will be spared 21 tons of CO₂ in that single decision.

The auto retailers do have some reasonable proposals to protect the environment. They are correct that a carbon tax on fuel gives drivers of both new and used vehicles a flexible incentive to save by driving less. They argue convincingly for stricter fuel guidelines that will give South Africans access to the cleanest new engines and improve the emissions of existing cars as well.

But global warming will not be stopped by drivers cutting back on kilometres. It will not go away because our fuel is cleaner. Nor will it be fixed by a carbon tax on inefficient new cars. It will take all of these approaches in combination and many more.

Many eminent scientists believe that to keep the earth from warming into the danger zone of higher than 2 degrees above pre-industrial levels, greenhouse gases will have to cut by 80 or even 90 percent in the developed world. We don’t need to choose the single best solution among many; we need to adopt all reasonable solutions.

The carbon tax on new vehicles is not perfect. It addresses only one facet of the problem, and the tax is calculated into the sticker prices instead of staring consumers in the face. But we consider it entirely acceptable to fund the government with imperfect taxes on such virtues as saving (interest tax), earning wages (income tax) spending (VAT) and running a successful business (corporate profits tax). Compared to these, a tax on the polluting capacity of new vehicles smells like a rose.

Our morning got off to a curious start, to my mind. When my 17-year-old finally awoke, my wife asked if she wanted to come along for a jog.

“No,” she replied, “I have an extra maths lesson in one hour.”

“That’s fine,” I said, to my wife. “You run, and I will walk her to maths.” (1.8 km away)

“Walk?,” exclaimed my wife, “She doesn’t have time for that; she has tons of homework.”

If the humour of this conversation does not immediately occur to you, perhaps you should exercise your mind. Our culture has compartmentalized each aspect of our lives so completely that exercise is a specialized activity done purely for its own sake and worth the time it requires. Traveling to school, work, shops, friends or errands is a separate activity, to be done as quickly as possible, by car. Using a slower mode of transport is a waste of time, even if it involves exercise. But my calculations show that traveling more slowly actually saves me time, in two ways.

I jog for exercise and pleasure and cycle to get around and also for pleasure. It horrifies me to see people who will ride a bicycle all the way to the Magaliesburg on a Saturday morning for fun, get home, shower and hop in the car to get to the post office. I’ve seen this happen.

My longest regular ride is to a weekly voice lesson. It’s a 7.5 km trip by car that takes 15 minutes, or a cycle of anywhere from 25 to 35 minutes. On the morning of my voice lesson, I skip my usual one-hour jog, saving the same time that it will take me to cycle in both directions. Jogging and then driving would together take an hour and a half. Cycling takes one hour. 60 + (15 x 2) – (30 x 2) = 30. I save a half hour.

That’s not all I save. I don’t keep track, but I figure that sometime this year I will have made my hundredth cycle to my lesson. 100 x (7.5 x 2) = 1,500. That’s 1,500 kms of driving I have saved—farther than Johannesburg to Cape Town—and 150 litres of petrol worth well over a thousand rand. The environment has been spared more than 350 kg of carbon dioxide.

Let’s exercise our maths some more. A health study following more than 5,000 people over 40 years concluded that exercise equivalent to walking for 30 minutes a day for five days a week adds 1.3 to 1.5 years to your life.  Do those regular walks for 30 years, and you will spend 234,000 minutes walking, (30 x 5 x 52 x 30 = 234,000) but will have added 735,840 minutes to your life. (1.4 x 60 x 24 x 365 = 735,840.) So the averages tell me that the 20 minute stroll to her maths lesson added perhaps an hour to my daughter’s life. 735,840 ÷ 234,000 x 20 = 62.89. And, she later reported, “It was a pleasant walk.”

1 + 1 = 2.

I keep track of my fuel economy with every fill-up. It’s a little obsessive, I know, but I’ve learned quite a lot from seeing the differences in economy between cars, drivers, seasons, tyres, etc. There is good research to show that when people are aware of consumption, they tend to reduce it. It’s also good to know whether the fuel economy gauge in your car is accurate. In my experience, the gauges always make your fuel consumption look better than it really is.

I’ve made the process very simple for myself by creating an Excel spreadsheet that instantly calculates kilometres per litre and litres per 100 kilometres, with a running average for the last ten fill-ups. Now I’m making it simple for you, too, with a downloadable blank spreadsheet that has all of the formulas to make those calculations. All you have to do is reset your trip odometer at each fill-up, record the number of kilometres on the till slip—which already has the litres printed on it—and enter those two numbers on the spreadsheet.

To have your own copy of the spreadsheet, click on this link:

FuelEconomy

You should then be offered the option of opening it directly in Excel or saving it. Either option works, but if you choose to open it directly and then wish to save it—using Save As—you must be very careful to save it in the folder where you keep spreadsheets. It will not automatically opt for the My Documents folder.

After using it, if you’re not pleased with the fuel economy you see, try my 10 Unconventional Tips for Saving Petrol.

Note: FuelEconomy.xls was scanned with a fully updated version of Norton AntiVirus 2009 immediately before it was uploaded to GreenerHouse. No viruses or other security risks were found. That said, GreenerHouse promises not to take credit for your improved fuel economy if you promise not to make GreenerHouse responsible for any troubles with your computer or your spouse arising from the use of this file.

With petrol breaking the R10 barrier today, I’m sure the newspapers will be hauling out the AA’s list of fuel-saving tips yet again. We’ve all read them least a dozen times. The list is generally sound: use the correct tyre pressure, don’t accelerate too quickly, etc., etc., etc. Our eyes are glazing over, however. It’s time for a new list. It’s time to push the envelope.

The fuel consumption numbers in the literature for new cars (and now on windshield stickers in South Africa) are useful for comparing between cars. But few people can keep their fuel consumption that low on the streets. The official stats are derived under very controlled conditions that don’t really reflect the habits of typical drivers.

I hate to brag, but I do consistently match or beat the official fuel consumption figures for the cars I drive. You can, too. Follow me.

[Lawyer's note: Use these tips at your own risk. GreenerHouse is not responsible for your prang. Safety first.]

1. Don’t brake.
2. Hold your right foot in the air
3. Watch your rev counter
4. In town, windows down
5. Ride the roller coaster
6. Drive your spouse’s car
7. Change your clocks
8. Know your numbers
9. Rearrange your “To Do” list
10. Drive farther . . .

1. Don’t brake

Ok, if a ball rolls out into the street with a child running behind it, slam on the brakes, but most braking is an unnecessary waste of energy. You must learn to feel guilty every time you brake, converting all of that good momentum your engine has given you into wasted friction and heat, requiring you to accelerate all over again.

Not braking requires planning ahead, allowing space in front of your vehicle and exercising patience. A typical example is a street with speed bumps. Most drivers accelerate after each bump and brake before each bump. It makes no sense. The bumps are there because the people who live on that street convinced the government that cars should drive slowly for the safety of the neighbourhood’s children and pedestrians. Settle into the speed at which your car can handle the bumps and stay there. Unless you’re heading downhill, you shouldn’t have to brake.

Look way ahead to the traffic lights and let your car slow naturally well in advance of a red light. People are always in a hurry to sit at a red robot, wanting to give the poor smash-and-grabbers a sporting chance. Don’t worry about the guy behind you flashing his headlights. You’re saving him petrol and a smashed window, too. Smile and wave.

If you have to brake at the bottom of a hill or before a curve, it probably means that you were accelerating unnecessarily a few moments before. Slow down in advance—it’s not safe to brake on a curve, anyway—and keep your foot off that darned brake.

(more…)

The Mail & Guardian has now put the full, uncut version of my diesel article on their website. Click here to read it.

If you’ve read my article in today’s Mail & Guardian, you already know that diesel is not quite the panacea to South Africa’s environmental problems that the advertisers would have you believe. South African diesel fuel is still much dirtier than the diesel available elsewhere, and so are our diesel cars. So they play a large part in the smog and particulate pollution in South African cities. The last two-fifths of the article were supposed to explain why diesel vehicles are also not quite the solution to global warming that some think they are, either. But that part of the article was lopped off at the last minute before printing, for some reason. Here’s the rest of the story . . .

. . . These problems are all local, however, and some would argue that the far-reaching impact of global warming means that some diesel pollution must be tolerated. But diesel’s potential for reducing greenhouse gas emissions is regularly overstated. BMW’s X5 brochure, for example, notes that their diesel model uses “up to a quarter less fuel than its competitors,” including the equivalent petrol X5. It adds that this “of course, means a reduction in the greenhouse gases responsible for global warming.”

One little-known reason for diesel’s superior efficiency, however, is that the fuel is denser than petrol, with more carbon. As a result, litre-for-litre it gives off more earth-warming carbon dioxide when burned. So in measuring the grams of CO₂ per kilometre, Britain’s Vehicle Certification Agency finds that the X5 3.0sd diesel is only 11 percent better for the atmosphere than the petrol version, despite having 25 percent better fuel economy. Fuel consumption “is only really useful in terms of amount of money you’re going to spend on fuel,” notes Frank Schwegler, president of South Africa’s National Association for Clean Air, “but greenhouse-gas emissions is quite a big factor to consider.”

For now, finding a car’s CO₂ emissions per kilometre at a dealership requires scrutinizing the fine print of a technical specifications sheet, if the figure is there at all. Starting in mid-2008, however, all new cars in South Africa will have to display this number—as well as litres per 100 kilometres—based on standardized measurements that can be compared between brands.

In the meantime, the Union of Concerned Scientists suggests that car shoppers should adjust a diesel car’s litres-per-100-km figure upward by 18 percent. Comparing the resulting figure with the fuel economy of a petrol vehicle puts the two on an equal footing as far as greenhouse-gas emissions are concerned.

Even after those adjustments, diesel engines remain somewhat more efficient than their petrol counterparts. And with cleaner Euro 3 and Euro 4 compliant vehicles arriving now in showrooms, some environmentally conscious consumers may decide to tolerate diesel’s local pollution—or the high cost of effective emission controls—in exchange for the lower greenhouse gas emissions. As if that decision was not complicated enough, a more vexing quandary faces diesel buyers at the filling station.

Since Sasol’s coal-to-liquids plant in Secunda is the largest source of ultra-low-sulphur diesel in South Africa, opting for 50 ppm sulphur diesel over ordinary 500 ppm actually quadruples the chances that the fuel in the pump is coal-based.

Sasol’s Fischer Tropsch coal-to-liquids process is an incredibly dirty way to make an incredibly clean fuel. Every drop of diesel that the company makes from coal is so low in sulphur—approximately 10 ppm—that it could be sold in virtually any country in the world.

But the Secunda facility emits about 60 million tons of carbon dioxide into the atmosphere each year. That’s barely less than the greenhouse gas emissions for all of Israel and its 7 million people. In making a litre of coal-to-liquids diesel or petrol, Sasol sends well over three kgs of greenhouse gases into the atmosphere, far more than a car will emit while driving on that litre.

Sasol already supplies half of all the ultra-low-sulphur diesel sold in South Africa, and it is the best situated to increase supply as demand rises. Bizarrely, Sasol has to sell most of its clean diesel as regular 500 ppm sulphur diesel for a lower price; demand for 50 ppm is not yet high enough. As sales of “green” diesel cars grow, Sasol can sell that same fuel for more money as ultra-low-sulphur to take a dominant market share in the 50 ppm segment.

It will be a sad irony when most of the millions of tons of greenhouse gases spewed by Sasol to make diesel is paid for by the drivers who bought the most “environmentally friendly” cars.

Even the complete version of my article on diesel fuel leaves some open questions. Before you ask, here are my answers:

So which car should I buy?

If the answer were simple, I would have fit it into the article. The conundrum is this:

Diesel cars emit somewhat less carbon dioxide. (Not as much less as you thought, but less nonetheless.) But diesel cars emit more local pollutants. But the newest, clean, Euro 4 diesels driving on ultra-low-sulphur fuel emit acceptable levels of local pollutants. But half of all the ultra-low-sulphur diesel in South Africa is made in a way that emits huge amounts of carbon dioxide.

You can’t win.

You also can’t use diesel as an excuse to buy a bigger, more powerful vehicle than you need. That’s exactly what the car companies are trying to get you to do. (See question below: “Why are SUVs cleanest?”) I think that most city dwellers, especially those on the Highveld, should buy the most fuel-efficient petrol car they can find that suits their needs. If you can afford it, the Toyota Prius is ultra-clean for both local pollutants and greenhouse gases.

If you live in a rural area in the Highveld, where local air pollution from traffic is not as much of an issue, you might consider buying a diesel vehicle and running it on normal, 500 ppm sulphur diesel. You are most likely to avoid coal-based fuel that way and will reduce your contribution to global warming. (Note that if your manufacturer says you must use ultra-low-sulphur fuel, it could damage your vehicle to use 500 ppm sulphur diesel.)

If you live in KwaZulu-Natal, most of your fuel comes from petroleum. With the coal issue set aside, diesel makes more sense. Look for the vehicle—petrol or diesel—with the lowest CO2 emissions that suits your needs. In KZN cities, you should only buy a diesel if it meets Euro 3 or Euro 4 specifications and fill it with ultra-low-sulphur diesel.

Cape Town is even more complicated. Fuel retailers generally buy from the nearest refinery, but Sasol transports ultra-low-sulphur diesel all the way from Secunda to its filling stations in Cape Town. I wouldn’t buy it. BP stations get their ultra-low-sulphur diesel from the Durban refinery that BP owns with Shell. I don’t know about the others.

Does a diesel make economic sense?

The Diesel Dilemma, a report by the Union of Concerned Scientists, concludes that:

Gasoline vehicles are more cost-effective than diesel for reducing oil use and lowering global warming pollution.

By that, they mean that if the extra expense it takes to make a clean diesel engine were put toward greater efficiency in petrol vehicles, the petrol vehicles would save more oil and greenhouse gases than diesel cars. Unfortunately, other than hybrids like the Prius, few petrol cars have benefited from that kind of attention toward fuel economy.

Looking at clean diesels available in South Africa, the BMW X5 sd costs an astounding R68,000 more than its petrol equivalent the X5 si. Even after 150,000 kms, you would be R47,000 poorer, at October’s fuel prices. The diesel Honda CRV, which has perhaps the most advanced diesel engine on earth, emits 10 percent less carbon dioxide than a similar petrol CRV and costs R20,000 more. After 150,000 kms, you would be only halfway toward recouping that differential.

I’m not a great believer that every expenditure for the sake of the environment must pay for itself. If someone in Durban really needs a 4×4 soft-roader and is willing to pay the extra money for the sake of the earth, they should buy a diesel CRV. I’m just not sure how many people out there really need a 4×4 soft-roader.

Smaller diesel cars may have a smaller price differential, but few if any small diesels in South Africa today are clean enough to meet Euro 4 emissions standards. In 2008, some will be available, and perhaps they will pay for themselves over time. They certainly will make more sense for the environment than a 3-litre diesel powerhouse with a lot of emissions controls on it.

Why are diesel SUVs cleanest?

The cleanest diesel engine BMW has brought to South Africa is in its giant X5. Honda’s cleanest diesel is on the 4×4 CRV. VW’s only Euro 4 vehicle in South Africa so far is the Touareg SUV. Volvo has put its best diesel emissions controls on the 4×4 XC. What’s going on here?

I put this question to Jan Lotter, the product planning manager for BMW South Africa. He laughed, and said that I had made a good observation. Then he said:

There’s a growing awareness of SUV consumption; people are talking about carbon footprints, environmental impact. This is a little more of an investment to make them more acceptable.

I think he’s right. It’s a last-ditch effort to keep people who are starting to feel that it’s environmentally unacceptable to drive a 4×4 to Sandton City from buying a smaller, less expensive car.

Lotter made another salient comment:

The unfortunate thing about diesel is that it is still expensive. With the invention of common rail diesel technology, and going to higher and higher pressures [to make diesel engines cleaner] it becomes difficult to introduce entry-level diesels.

BMW has a small, Euro 4 diesel car that can even beat Toyota’s Prius in fuel efficiency, the 118d. But it isn’t sold in South Africa.

Does it really make a difference whether I buy coal-based fuel?

One could argue that avoiding coal-based ultra-low-sulphur diesel from Sasol’s Secunda plant does nothing for the environment. Fuel is in short supply in this country and Sasol will keep producing to capacity. The company may end up selling the fuel as regular diesel and it may end up selling the diesel somewhere else, but Secunda’s emissions are not going to decline just because fewer people buy ultra-low-sulphur diesel in the interior.

This argument has some validity, but I would make three counter-arguments:

1. Sasol makes more profit selling their diesel as ultra-low-sulphur diesel. The more profit they make on diesel, the more likely they are to go ahead with the second coal-to-liquids plant, which is now in the feasibility-study stage. Such a plant would be a disaster for South Africa’s greenhouse gas emissions.
2. If ultra-low-sulphur diesel becomes in short supply, the government may be more favourably inclined toward another coal-to-liquids plant.
3. It might just bother your conscience to think that the source of all those greenhouse gas emissions killing polar bears and ruining the crops of African farmers is sloshing around in your fuel tank.

Don’t you have anything nice to say about Sasol?

Sasol does an impressive job of reporting emissions data and was willing to let some of its experts talk to me openly for this story. The refinery owned by BP and Shell, by contrast, would only answer questions by email and mostly didn’t answer questions at all. Sasol’s greenhouse gas emissions are edging down relative to their total production, partly because they are using more gas from Mozambique, which is less polluting than coal. There, I managed to say something nice about Sasol. (But if you haven’t read the M&G article yet, their Secunda plant has roughly the same greenhouse-gas emissions as Israel.)

Don’t you have anything nice to say about BMW?

I’m afraid that BMW’s marketers set themselves up for criticism by portraying a big SUV as a solution to global warming. That said, the company is working on some very interesting technologies for improving the fuel consumption of both petrol and diesel vehicles. In 2008 we may see the first BMWs that cut the engine instead of idling at a stop light and use the energy from braking to recharge the battery.

It has always bothered me that South Africans take such an interest in topping off their petrol tanks when fueling. Some have elevated it into a kind of sport. I once watched a man bouncing up and down on his bumper in an effort to slosh the fuel around in his tank and squeeze a bit more in. I’m convinced that petrol attendants have some fancy mathematical formula they use when topping off to get the amount due to a suitably un-rounded number that will maximize their tip when customers say, “keep the change.”

The loser in this game is the air we breathe. Petrol vapours are carcinogenic, and, given a little time and sunshine, they create smog. Overfilled fuel tanks are likely to leak, especially if parked in the sun. Topping off greatly increases the likelihood of a spill, and even a minor spill is bad news. Just a shot-glass (30 ml) of spilled petrol gives off the same volume of smog-forming VOCs (Volatile Organic Compounds) that a car emits when driving 90 kilometres.

The issue is so serious that in the U.S., nearly every fuel pump you see at filling stations has a “Don’t Top Off” sign on it. Some U.S. States even sponsored a “Don’t Top Off” week, to get the message across. The U.S. Environmental Protection Agency has a whole web page devoted to the subject.

It’s a lot easier to do the right thing if you know it has some direct impact on your wallet, so these campaigns also emphasize that overfilling means paying for petrol your car might never use. Yesterday I read another reason that continuing to add fuel to a tank after the pump has automatically shut off could cost you money. The New York Times ran an article about the tricks some car-owners have used to keep their vehicles going after 200 000, 300 000, and even 400 000 miles. (These are miles, not kilometres.) The Times offered this advice from Toronto mechanic Vladimir Samarin, who has a car-care Web site at www.samarins.com.

Mr. Samarin also warned drivers not to overfill their fuel tanks. “Otherwise you could get fuel into the vapor canister,” he said. If that happens, the charcoal in the canister could find its way into the fuel lines and cause damage. “When you get that first click of the gas pump, stop refueling.”

Of course it would be nice if the government or the petrol retailers could take the lead in this issue. As far as I can tell, they have done nothing. Until they do, tell your petrol-station attendant that his tip will be bigger if he stops at the click.

You can’t always be certain that doing your bit for the earth will save you money, but driving less will. I ran some figures through a spreadsheet and figured that for each 100 kms not driven, a typical person could save R129*, or more than a rand a kilometre. Of the R129, R55 is petrol savings, the rest is wear and tear on the car.

An article in the latest Mail & Guardian suggests that staying at home could save a person even more with a new auto insurance policy from Hollard Insurance. I don’t have any personal experience with Hollard or this particular policy, but the writer, Maya Fisher-French, says that for every kilometre she doesn’t drive in a given month, she saves 21c on her premium. She claims that as a light driver, Hollard’s Pay As You Drive policy is saving her R460 a month.

If I add another 21c savings for each of my 100 kms not driven, my total savings would be up to R150. Imagine how driving habits might change if we had to pull R150 from our wallets every time we drove 100 kms.

I can’t personally vouch for the Pay As You Drive policy, but I will say this: if a company is pricing its product in a way that gives clear incentives for doing the right thing, that company is itself doing the right thing.

*These were the reasonable-but-not-terribly-scientific assumptions I used. Fuel consumption: 10l/100km. Fuel price: R5,50. A car that loses R100 000 in value after driving it 200 000 kms. R3 500 tyres that last 40,000 kms. R1 500 service every 10 000 kms.