Showing posts with label car. Show all posts
Showing posts with label car. Show all posts
Monday, August 24, 2009
Toyota Prius Redux
You might have seen the adverts for the "next Toyota Prius", so Disgruntled tried to find out some information about this new model, so that he could compare it as he did before here. From the Toyota website, we find that the fuel efficiency of the next Prius is 72.4 mpg on the combined cycle, an improvement from the previous 65.7 mpg, but still lower than the VW Polo Bluemotion at 74.3 mpg. It also says that the CO2 emissions are "as low as" and "from" 89g/km, but doesn't say under what conditions - one assumes that this is under the best conditions possible, as if it uses more fuel than the VW, then the emissions are most likely to be higher. But I could be wrong here - Toyota need to clarify exactly what they mean. I still stand by my earlier conclusion - buy the VW, it is more fuel efficient and far cheaper.
Thursday, June 25, 2009
More on fuel efficiency and emissions
If you think that the answer to the Toyota Prius of VW Polo Bluemotion is an electric vehicle, consider the following figures:-
Figures from IET Engineering & Technology magazine, 6th-19th June 2009, pg 22
How green your electric vehicle is will depend very much on the generation source of its power, not taking into account the battery technology used, and if it is Lithium Ion batteries, then it will suffer in the same way as the Toyota Prius. Green cars either need a whole new power source, or a much greener source for the electricity generating stations. Without either of them, then the "green revolution" in motoring will be all hype and no substance.
| Electricity source | CO2 emissions (g/km) |
| Coal | 122.07 |
| Oil | 85.54 |
| Gas | 52.65 |
| Nuclear & Renewable | 0 |
Figures from IET Engineering & Technology magazine, 6th-19th June 2009, pg 22
How green your electric vehicle is will depend very much on the generation source of its power, not taking into account the battery technology used, and if it is Lithium Ion batteries, then it will suffer in the same way as the Toyota Prius. Green cars either need a whole new power source, or a much greener source for the electricity generating stations. Without either of them, then the "green revolution" in motoring will be all hype and no substance.
Tuesday, June 23, 2009
Why Public Transport Policy Will Not Work
When quoting the costs of transport, the government frequently quotes from figures compiled by the AA which give an average figure per mile for each different type of car taking into account the costs of ownership, depreciation and the like. A typical figure for an average car is something like 40 pence per mile. This is then compared against the cost of taking public transport to try and show that public transport is cheaper.
However, this is a fallacy. Whether I use my car only once per year, or whether I use it every day, I still have to insure the car, I still have to tax it, I still have to get an MOT, and it will still depreciate. Thus when considering the cost of a journey, you don’t take these into account – they are sunk costs which I have to pay whether or not I take the journey by public transport or in my own car. What you take into account are the cost of fuel for the journey, the extra wear and tear caused, and the time. This is what public transport has to compete against, not the overall figure of the lifetime cost of the car. That lifetime cost is also somewhat artificial, as the more I drive my car, the smaller it gets as you can divide down the total cost by an increasing number of files until you hit a limit due to fuel and repair costs.
For further comparison, consider a journey I often make to the local regional shopping centre, a round trip of seven miles. At 40p per mile, that comes to a cost of £2.80. The local bus company wants £3.60 for the same journey, assuming that I can a return ticket (which you cannot buy at certain times). The journey typically takes 12 minutes each way by car, and 45 minutes by bus. That £2.80 is the same cost irrespective of how many people I have in the car, whereas the bus will charge for each passenger. Therefore per person it gets cheaper to take more in the car, whereas it gets more expensive by bus. If you are a family you take the car – it is quicker, and far, far cheaper. And this is just a short journey.
Long distance is no better. Consider a trip to London. If I suddenly find that I need to take a trip to London in the next couple of days, so that I cannot use a cheaper fare, I am likely to find that the ticket will cost something like £70-£80, and will take 1.5 hours. It is a 250 mile round trip. By car the time is 2 hours, and it costs £40 in petrol. If I take three people with me, that is £10 per person. If we went by train, it is still £70 per person, as we each have to pay the same fare. Thus if I go to London, I drive to Richmond, park in the car park next to the tube station (£13 for the day), and take the tube in and save myself a packet.
Thus the government is actually making it more cost effective for us to use the car due to faulty economics. Because the sunk costs are so large for having a car, the marginal cost of each journey is actually quite small, and works out cheaper than public transport. On short journeys it is often quicker (and certainly more reliable – busses may or may not turn up, may not even stop if they do…..), and on longer journeys the costs saved more than make up for the extra time taken, and with our inter-city trains being so slow, the time lost might not be that much either. You are penalised for taking public transport if you are a family, as you have to pay for each person individually, whereas you don’t when taking your car. Until the government realises this and makes it more economically attractive to use public transport, we will continue to use our cars and gridlock be damned. It’s simply not worth our while to change our behaviour.
However, this is a fallacy. Whether I use my car only once per year, or whether I use it every day, I still have to insure the car, I still have to tax it, I still have to get an MOT, and it will still depreciate. Thus when considering the cost of a journey, you don’t take these into account – they are sunk costs which I have to pay whether or not I take the journey by public transport or in my own car. What you take into account are the cost of fuel for the journey, the extra wear and tear caused, and the time. This is what public transport has to compete against, not the overall figure of the lifetime cost of the car. That lifetime cost is also somewhat artificial, as the more I drive my car, the smaller it gets as you can divide down the total cost by an increasing number of files until you hit a limit due to fuel and repair costs.
For further comparison, consider a journey I often make to the local regional shopping centre, a round trip of seven miles. At 40p per mile, that comes to a cost of £2.80. The local bus company wants £3.60 for the same journey, assuming that I can a return ticket (which you cannot buy at certain times). The journey typically takes 12 minutes each way by car, and 45 minutes by bus. That £2.80 is the same cost irrespective of how many people I have in the car, whereas the bus will charge for each passenger. Therefore per person it gets cheaper to take more in the car, whereas it gets more expensive by bus. If you are a family you take the car – it is quicker, and far, far cheaper. And this is just a short journey.
Long distance is no better. Consider a trip to London. If I suddenly find that I need to take a trip to London in the next couple of days, so that I cannot use a cheaper fare, I am likely to find that the ticket will cost something like £70-£80, and will take 1.5 hours. It is a 250 mile round trip. By car the time is 2 hours, and it costs £40 in petrol. If I take three people with me, that is £10 per person. If we went by train, it is still £70 per person, as we each have to pay the same fare. Thus if I go to London, I drive to Richmond, park in the car park next to the tube station (£13 for the day), and take the tube in and save myself a packet.
Thus the government is actually making it more cost effective for us to use the car due to faulty economics. Because the sunk costs are so large for having a car, the marginal cost of each journey is actually quite small, and works out cheaper than public transport. On short journeys it is often quicker (and certainly more reliable – busses may or may not turn up, may not even stop if they do…..), and on longer journeys the costs saved more than make up for the extra time taken, and with our inter-city trains being so slow, the time lost might not be that much either. You are penalised for taking public transport if you are a family, as you have to pay for each person individually, whereas you don’t when taking your car. Until the government realises this and makes it more economically attractive to use public transport, we will continue to use our cars and gridlock be damned. It’s simply not worth our while to change our behaviour.
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