Howard:

First, welcome to the Board, congratulations on your purchase, and I want your engine. (We don't get the 3.0 oil-burner here in the colonies. <img border="0" title="" alt="[Wink]" src="images/icons/wink.gif" /> )

Anyway, I don't have enough specific information about your truck to say whether the dealer's blowing smoke, but the explanation isn't outside the realm of logic. I know that diesels have a heck-of-a-lot more compression than petrol engines, and (in the past, at least) there were diesel-specific batteries with much higher "cold-cranking-amp" ratings to overcome that compression upon start-up. Given how warm it usually isn't in the UK, and the draining effect of cold on a battery, the dealer's explanation makes sense. The key is whether that set-up is standard on the 3.0TD Trooper.

You might try The Isuzu Deisel Forum for some better information.

Hope this helps, and good luck.
Kevin