Does a corn-ethanol vehicle beat the Tesla Roadster in lifetime CO₂ emissions?

What does it take for a car to "beat" the Tesla Roadster? With a 0-60 time that blows away almost anything else on four wheels, there aren't many vehicles that are faster. With an all-electric drivetrain, the car sits at the absolute pinnacle (along with every other EV) for lowest tailpipe emissions. But is it possible that a vehicle that burns corn-based ethanol (or gasoline!) can beat the Roadster on overall CO₂ emissions?

This is the claim from the unbiased folks at Biofuels Digest, who crunched theoretical numbers like this:

• The Tesla gets its juice from a power plant that is burning coal, which means it has 2.095 pounds of CO₂ per kWh and can go 3.12 miles per kWh.
• The theoretical corn-ethanol E85-burning vehicle puts out CO₂ according to the GREET model (Greenhouse gases, Regulated Emissions, and Energy use in Transportation) for lifecycle emissions and is operating at the proposed new CAFE standards.

Over the vehicles' lifetimes (of 145,000 miles), Biofuels Digest says, the E85 vehicle creates 30 percent fewer CO₂ emissions, and the Roadster will even put out 21 percent more CO₂ than a car that uses straight gasoline (we tried to dig into the GREET model to see how deep the well-to-wheels model tracks CO₂ generation, but didn't see how crop and oil production is specifically handled here. Since GREET has been in development since 1999, we're going to assume the system takes these factors into account). Biofuels Digest uses government data – from the EIA, DOT, Argonne National Lab, etc. – and Tesla's numbers to come to their conclusion. You can find a chart produced by Biofuels Digest after the jump.

At first glance, this reminds us of the Prius vs. Hummer debacle, but we're open to further investigation. Got an opinion?

[Source: Biofuels Digest via Domestic Fuel]