Such changes are often done to denote a modification in engine displacement.

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The radical minimalism of these machines, built mostly in Europe in the 1950s and early '60s, reflected the region's postwar scarcity. (One resourceful builder beat old cooking pots into fender panels.) They typically measure 10 feet long or less, with less than 700-cc engine displacement and one or two seats arranged side by side or in tandem, scooter style.

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Inadequate in the smaller Jetta and a cruel joke in the Passat, the 2.5L will be replaced with a small-displacement gas-turbo engine for model-year 2013, and not a second too soon.

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