[okie01]

I don't know what that means. Translation?

The price spread.

Diesel is now approaching $4/gal. The cost of an equivalent amount of energy from natural gas is less than $2.

[thackney]

A gallon of diesel fuel cost an average of $3.97 last year, according to federal statistics. The equivalent amount of energy in natural gas cost 48 cents at industrial prices.

Berkshire’s BNSF Railway to Test Switch to Natural Gas
http://online.wsj.com/article/SB10001424127887324539404578342540494619344.html

To get around the subscription requirement for some Wall Street Journal articles, you can search for the title and click the link from the search engine.

https://www.google.com/search?q=Berkshire’s+BNSF+Railway+to+Test+Switch+to+Natural+Gas&aq=f&oq=Berkshire’s+BNSF+Railway+to+Test+Switch+to+Natural+Gas&aqs=chrome.0.57j61l3j62l2.512&sourceid=chrome&ie=UTF-8

First link at the above search.