Tuesday 15 October 2013

GM disappoints with its 2015 SUVs

Anyone expecting General Motors (GM) to slot in its ‘stillborn’ 4.5-litre V8 turbodiesel into the 2015 Chevrolet Tahoe, GMC Yukon and Cadillac Escalade full-size sports utility vehicles (SUVs) is disappointed.

Instead, The General took the low road and announced these vehicles would carry the well-tried 5.3-litre and 6.2-litre EcoTec3 V8 engines and six-speed transmissions. This is the same line-up the company introduced in the 2014 Chevrolet Silverado and GMC Sierra.

But this may not be the end of the story. For surely GM cannot afford to write off all the engineering expertise it poured over a number of years into the compact V8 diesel it shelved just prior to its 2009 bankruptcy and reorganization.

To all intents and purposes, GM has completed development on the new 4.5-liter turbodiesel V-8 destined for use in half-ton pick-up trucks. At its launch, the company’s engineers much hyped the principal features of the engine; they singled out its narrow-angle cylinder banks, reverse-flow heads, dual overhead camshafts, and its compacted graphite iron (CGI) block. Features aimed at achieving compactness and lower weight.

The engine was designed to slot into the space allocated to a conventional small-block gasoline V8. And GM officials even nominated the huge Tonawanda engine plant in upstate New York as the most likely location for production.

It remains a mystery to journalists at this stage if the engine will reach production. But GM insiders must know the ropes. Many outsiders hope too that it will reach production as other North American manufacturers are lining themselves up to make greater use of vee diesels.

The only hint seems to come from Jeff Luke, executive chief engineer for GM trucks, who is reported as saying that GM’s large SUVs may soon be receiving eight- and maybe even 10-speed transmissions, as well as other powertrain variations, such as hybrid and possibly even diesel variants. http://www.trucktrend.com/features/news/2013/163_news131014_new_gm_full_size_suvs_could_get_hybrid_diesel_options/#ixzz2hocOdw62

The hybrid versions of the last-generation SUVs did not appear to be as popular as first hoped, and while they achieved significantly improved city fuel economy than the conventional models, the difference in highway fuel economy was minimal, to which the added cost was substantial.

So the jury is still out. Though with Chrysler, Ford and Nissan in the frame with vee diesels equipped with CGI cylinder blocks, not to mention Cummins Inc. that is standing by to supply anyone who wants a 5-litre vee diesel with CGI block from its Columbus plant, it seems unlikely that GM will not travel down the same road, given that it has done all the homework with its own 4.5-litre CGI V8 turbodiesel. That Chrysler uses a CGI engine in which GM has a half-share with Fiat (VM Motori) is surely a pointer to the future.      ∎

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