HOLDEN’S new-model steamroller is forging forward relentlessly, with the recently released Captiva V6 gaining a four-cylinder turbo-diesel sibling. Reeling from slow sales of its excellent Astra CDTi range, Holden is determined to make this diesel application sell, and has priced it so closely to the petrol-powered models that we beg the question: why would you bother with anything other than the diesel models?