It looks like the combination of $4/gallon gas and CAFE rules may have finally administered the coup de grace to GM's plans for new rear wheel drive replacements for its big sedans. GM had been planning to replace the Chevrolet Impala and Buick Lucerne with models based on the same Zeta rear wheel drive platform as the Pontiac G8 around 2010. However, it now appears that the front wheel drive Impala will remain in production at GM's Oshawa Ontario plant until at least 2012. The new contract between GM and the Canadian Autoworkers union specifies that the popular Impala will live on. Most likely it will now get a visual refresh around 2010 and probably some powertrain upgrades to improve efficiency. The fate of the Buick remains uncertain. The Hamtramck assembly plant that currently produces the Lucerne and Cadillac DTS is scheduled to shift over to building a Delta platform MPV and some car called the Volt in 2010. Based on the current draft of CAFE rules, it seems GM could have likely met the requirements with a Zeta platform vehicle with smaller, more efficient engines and perhaps a hybrid powertrain. The seemingly inexorable shift to even more efficient vehicles driven by higher gas prices is likely to continue outstripping regulatory requirements for the foreseeable future and all the automakers are having to adjust quickly.
[Source: Automotive News - Sub. req'd