New Car verses Old Car

As the economic climate collapses around us, many people are putting off their purchase of a new car and making do with what they already have. Old cars are bad and polluting, new cars are clean and efficient right? So this is a bad thing?

Not necessarily. The SMMT say that the average new car generates 1 tonne of CO2 to build (lets ignore the raw material / recycling arguments for the moment). We also know from the DfT that the average car in the UK travels about 10,000 miles per year.

Let’s say that you haven’t had to sell your children into slavery as a result of the credit crunch, and in fact you’re on the market for a new Mini. Well, let’s just imagine that those people still exist.

BMW as a company has become one of the leaders in the field of fuel efficiency improvement with their so called “mild hybrid” systems. The calculation is shown below:

Carbon Credentials of Minis

Carbon Credentials of Minis

The conclusion then is that to make the CO2 Savings for the base model MINI you have to drive more than 62,000 miles. So after 6 and a bit years you will have made a positive impact on the environment by buying a cleaner car.

So what about the fuel savings? The calculation for the mpg (fuel economy figures) are below as well:

Fuel Credentials of Minis

Fuel Credentials of Minis

Given that the average spend on fuel per year per car is about £1,000, how long would it take to save 10% of that, or £100? Well, 16,000 miles on the base model MINI.

Considering that a base model MINI retailing at about £11,000 and will lose just 15% of it’s value (£1,650) in the first year (it’s the slowest depreciating car you can buy currently), then saving £60 in fuel is pretty minimal.

2007 Mini One

2007 Mini One

Obviously if you decide to replace your 30 mpg petrol car with a similarly priced second hand 40 mpg petrol car, then you can expect to save about £340 and 880kg of CO2. Which is not to be sniffed at, especially when you consider the further savings in tax, insurance and so on.

So should you buy a new car for environmental reasons? Probably not. Buy a smaller second hand car instead. Or learn to drive more efficiently.

2008 Mini One

2008 Mini One

Should you buy a new car to save money on fuel? Definitely not. You’d have to madder than a box of frogs.

Should you buy a new car because you want to? Of course, that’s one the delights of living in a free country. In fact at the moment you’ll probably get a very good deal indeed as most car markers are looking down the barrel of bankruptcy. But just don’t try to justify it for money saving or environmental reasons…


Head of it's time?

Ahead of it's time

So someone asks you what the lowest CO2 of any car on sale on the UK is. Must be the Toyota Prius right? That’s been on sale since 2000 in saloon form and 2004 as a hatchback, long before anyone gave a monkey’s about CO2…

Well the most interesting thing is that the Prius was top of the class for just 2 years, and it superseded a car which produced 20% less CO2 than any car on sale today. Progress eh?

Between 2000 and 2005 (when it was no longer on sale), the cleanest car in the UK was a little-known, slightly strange looking vehicle called the Honda Insight. A hybrid ahead of its time, it produced just 80g/km. To put that in context, the Toyota Prius produces 104g/km. A good secondhand one will cost you from £4,000 now in the UK. (

The Toyota did indeed reign king of the clean cars for 2006 & 2007, but has recently dropped back to 3rd= place – a position that can only get worse until Toyota release the next generation Prius, promised for 2009/2010. Currently the lowest CO2 producers sold in the UK are the Ecomotion Seat Ibiza and the BlueMotion VW Polo, both from the VW group. So the current (as of the beginning of September 2008) top ten* are:

SEAT Ibiza 1.4 TDI 80PS Ecomotion (99 g/km CO2 – Diesel)

VOLKSWAGEN Polo 3 / 5 Door 1.4 TDI (80 PS) BLUEMOTION (99 g/km CO2 – Diesel)

MINI MINI Hatchback R56 MINI Cooper D Hatchback (104 g/km CO2 – Diesel)

TOYOTA Prius 1.5 VVT-i Hybrid (104 g/km CO2 – Petrol Hybrid)

CITROEN C1 1.0i 3 & 5 door (108 g/km CO2 – Petrol)

TOYOTA Aygo 1.0 VVT-i 3 & 5 door (108 g/km CO2 – Petrol)

CITROEN C1 1.4HDi (109 g/km CO2 – Diesel)

HONDA Civic Hybrid 1.4 IMA ES (109 g/km CO2 – Petrol Hybrid)

PEUGEOT 107 1.0 (68 bhp) (109 g/km CO2 – Petrol)

SKODA New Fabia 1.4 TDI 80PS Green-Line (109 g/km CO2 – Diesel)

*I have removed duplicates of the same car, for example with different bodyshells.

N.B. Electric cars such as the G-Wiz have been ignored, however they tend to be circa 65g/km if you take into account the production of electricity.