Behind Audi's Biodiesel Victory At The 24 Hours Of Le Mans

One of the more interesting but overlooked facts from the 2008 24 Hours of Le Mans was that the Audi R10 TDI cars not only ran, but won, on a mixture of Shell V-Power Gas-To-Liquid (GTL) racing diesel and a newly designed Biomass-to-Diesel (BTL) fuel. We've been fascinated with prospects of biomass diesel since taking a trip to the Sears Tower in the algae van, as BTL offers cleaner output, has no fossil-fuel base and doesn't interfere with the food chain. The version used in the race cars was also 90% cleaner than American low-sulfur diesel. We talked with Audi of America's Christian Bokich about his experience at Le Mans with the winning diesel team.

Why biodiesel in a racing car?
Christian Bokich: We're racing to show people what's coming in our future cars, and to show that we're leaders in diesel. It has always raced on GTL; it's not from an oil barrel, it's from natural gas using a high-tech conversion. The new twist is the GTL was only the stop-gap to learn how to create synthetic diesel. We know we wanted to do biomass diesel, not based on foodstuffs.

Racing is fun. Racing is exciting. But we're racing for a reason: A to win, and B to bring the technology to customers. Though we don't recommend more than 5% biodiesel in our cars now, we want to say for the future you can use it in one of our new cars with a full warranty, and racing is an easy way to test that technology.

Did you have to make any adjustments to the cars to run the mixed fuel?
We did not. There were no adjustments.

You ran a mix of GTL and BTL, that's what you're trumpeting, but did you run it the whole time?
We were running the fuel mixture the entire race. There was no night-time mixture or day-time mixture.

WIll you continue to use BTL or is this a one-off race, albeit a successful one, with a low mix?
I think eventually you'll see higher mixes. We haven't announced what's going to happen now with the remainder of the US races we have. I assume we will continue. I think if we start using it now it would only make sense to keep using it now.

What's better, ethanol or diesel? You race against the E85-powered Vette; do you want to talk some smack?
Diesel offers the benefits that ethanol might have, but we have tremendous amounts of range. The R10 TDI, if it were not for the restrictions that were placed to put our cars on a level playing field, not only on the size of the gas tank but the rate at which we can refill, we could go lap and lap and lap without refueling.

Sure, we think diesel has an advantage over ethanol. The fact that we're using BTL that just uses garbage is a sign that we're investing in technology that uses a lot of existing resources. From what we know, ethanol does interfere with the human food chain.

This was your first trip to Le Mans, how was it?
I've never seen a race that seems more prestigious. I've been to the Indy 500, to all the ALMS races for two-years running. I guess the length of the race itself is prestigious. The regalia and the tradition that goes with it. We arrived and we went to this parade and they have all these fancy cars. And you look at the caliber of the people walking around. It's just an exciting and enthralling place. It was overwhelming, but it was kind of cool. I don't get very euphoric at times, but it was pretty easy to get euphoric about it.

[Photos: Robin Thompson for Audi of America]