Hey Finally a question that I have first hand knowledge, I work with Industrial Diesels and have had a Ford F250, with a 7.3L IHC. But here is the Skiny a Diesel Engine works solely on Compression so you have to Turn the Engine hard to get the Diesel to Expolde and also the Diesels have Glow plugs, which pre-heat the combustion chamber prior to starting the engine. Which are basicly a Resistance that has to be red hot to warm the chamber. Which take a lot of current. Thats why Diesels either have a Big Battery or 2 Batteries. Anything else I can answer feel free. <img border="0" alt="[Elvis]" title="" src="graemlins/elvis.gif" />