THE Grand Cherokee's V8 is an all-new design using alloy cylinder heads and a cast-iron block. Weight saving techniques included hollow camshafts, magnesium valve gear covers and a composite intake manifold as well as lightweight accessories such as the alternator, power steering pump and air-conditioning compressor. The weight reduction compared to previous Jeep V8s (not available here) is 24kg. The sequentially fuel injected single overhead camshaft engine also uses separate ignition coils for each cylinder and is designed for an operating life of 240,000km without major part replacements. Its idle speed is particularly low at 250-300rpm, partly due to the use of a hybrid cooling system using engine-driven and electric cooling fans.