Crude Oil

Tuesday 9th November, 2010
What’s black and swears? It may be the punchline of an awful joke, but Crude Oil is easily the lifeblood of the motor industry. As well as supplying the obvious fuel and lubricants they need, it’s also a vital raw material in the manufacture of plastics used in car bodywork, dashboards and artificial fibres for seat materials and carpets. If that’s not enough, add in paints, detergents, solvents, adhesives, rubber and even bitumen for tarmac. Whatever fuel we use to power our cars, Crude Oil and refineries are going to be required for decades yet.

But how much fuel is actually in a $78 barrel of crude and how far will it get a vehicle down the road?

In the UK, we predominantly use light Brent Crude from the North Sea. Typically, a 42 US gallon barrel of Brent will yield 3% LPG, 37% petrol, 25% diesel, 20% kerosene and 12% fuel oil. By comparison, a heavy crude oil would yield a much smaller proportion of petrol, diesel and kerosene - perhaps half that of Brent.

So, if we do the maths, we get about 5 litres of LPG, 59 litres of petrol and 40 litres of diesel - not bad at all for a single £49 barrel! It also goes some way to explaining why, when demand increased, the diesel price rose above that for unleaded. There is simply more petrol in each barrel, so it’s cheaper to produce.

Given that there’s around 50% more petrol in each barrel, we can swiftly conclude that a 40mpg petrol car actually has almost equivalent raw fuel efficiency to a 60mpg diesel vehicle.

To put that in real terms, the 72.43mpg Toyota Prius could travel 937miles on a refined barrel of Brent Crude. By comparison, the 74.3mpg VW Golf Bluemotion would manage just 650miles on a barrel. I’m sure you’ll agree that’s quite a marked difference for 2 cars that, in the brochure, look to have very similar fuel economy. If we’re talking about usage of the Earth’s limited natural resources, they’re worlds apart.

Clearly, wearing our environmental hat, car companies have a lot of work to do when it comes to communicating Green issues to customers, so in future articles we’ll analyse this in more detail and investigate alternative fuels such as electricity, bio-fuels and hydrogen. How environmentally friendly are these new options and is there a better way of comparing their green credentials than traditional mpg and newer CO2 emissions?

  1. 1) Michael Boxwell Said: (17/11/2010 12:07:45 GMT) Gravatar Image
    Crude Oil

    A very good article. As you point out, however, different crude oils produce different yields and the oil that comes from the middle east produces far more diesel and that figure can be closer to 50:50 between diesel and petrol.

    Oil refineries also 'crack' oil to make more of the heavy oils suitable for use in car engines. Cracked oil is more likely to be used in diesel production than petrol because diesel is a much denser fuel source.

    However, this cracking is done at a much higher environmental cost than simply refining the oil... so you are back to your swings and roundabouts again.

  2. 2) Ben Rose Said: (17/11/2010 12:12:12 GMT) Gravatar Image
    Crude Oil

    Thanks for the input, Mike.

    I know there are many different types of oil, which is why I went out of my way to ensure I specified which one. As I'm a UK guy, I stuck with the oil we use here and affects UK drivers. It's a very different picture overseas, for sure.

    My figures were supplied by real oil companies and refineries and best case output figures for both petrol and diesel.

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