Here's a link to the paper mentioned in the article (abstract only as this is an SAE document): http://www.sae.org/technical/papers/670175 http://www.sae.org/t

Here's a link to the paper mentioned in the article (abstract only as this is an SAE document): http://www.sae.org/technical/papers/670175 http://www.sae.org/technical/papers/670175