Let me begin by saying I don’t really believe what follows. But I can’t find any explanation. So please if you know, get in touch so I can sleep better. Thanks.
A few weeks ago, while I was still in London, I helped a friend buy a new car. I was a little wary. She’d just got a new job and a handsome pay rise with it. I knew she was interested in buying something withâ€¦let’s just call it a little extra “performance”.
Performance comes with a cost, both environmental and financial. Still, I figured I had a better chance of making the point if I was along for the ride, so I braved an afternoon of Vorsprung Durch Technik™ in Ultimate Driving Machines™ Unlike Any Other™.
We started at the Audi dealer. Now, in the interest of full disclosure, I’ve driven these things, and they’re fun. But they have miserable fuel economy. Or at least so I thought. As we entered the showroom I made a beeline for the technical brochure. The A4 2.0L TFSI 200hp (6-speed manual) promises what I thought to be an impressive (for its size and power) 36.7 average miles per gallon.
I struggled to reconcile this with my recollections of the gas-guzzling US equivalent. And I’m still struggling. The US Audi website also lists a 2.0L TFSI 200hp (also 6-speed manual). But its combined efficiency is 23 mpg.
So why the massive 50% increase in consumption for a few thousand miles across the Atlantic? Well first, because a US gallon is smaller than the UK gallon. No need to get into it here — but you can find the details on Wikipedia. (For those that ever wondered, this is why the pint in the Queen Vic is 20% bigger than a pint in Cheers).
To avoid confusion, I’m converting into a third measure: liters per 100km (L/100km). A very handy conversion tool by Mark Porthouse shows that the UK A4 uses 7.7 L/100km while the US car drinks 10.2 L/100km. So we’ve narrowed the gap, but that’s still a 25% efficiency improvement for the UK version of the car.
I’ve scanned through the technical data, I’m pretty certain I’m looking at the same car. The only remaining difference I can think of is the testing methodology. It’s true that the EPA guidelines for measuring fuel economy are different from those in the EU (you can compare the two) but I still can’t discern any obvious reason for such a big difference.
So, unless I’ve missed something obvious, this week’s conservation tip: If you buy a European car, buy it from Europe, because it’s more fuel efficient.
You may (reasonably) be wondering about the carbon impact of the shipping. I’ve calculated (xls) that at roughly 0.08 metric tonnes (approximately 175 lbs carbon) per vehicle. By my calculations, and using this data, you’ll save that in around one month of driving the European car. It’ll cost you a bit more though. At current gas prices, you won’t see the financial payoff for 60 years!
Now, please, tell me where I’ve gone wrong!