Buick launched its mid-size Regal sedan in late 2010 as a 2011 model, with the Turbo, high-performance GS and eAssist models following suit over the past year. Now, General Motors’ tri-shield arm has announced a couple of powertrain updates that will go into effect for the 2013 model year, namely the discontinuation of the naturally aspirated 2.4-liter inline-four in the base Regal.

Funk Flex

For 2013, the Regal’s standard engine is the 2.4-liter eAssit powerplant – a mill that, according to the EPA, is good for up to 36 miles per gallon on the highway. Buick pulled a similar stunt with its larger LaCrosse, killing off the base 2.4 in favor of the eAssist powertrain with a V6 available as a no-cost option. That said, Buick has not announced pricing for the updated 2013 Regal line, but we’ll be interested to see if the 220-horsepower 2.0-liter inline-four of the Regal Turbo will be available at no additional cost.

The 270-hp Regal GS carries over largely unchanged, though as initially promised, a six-speed automatic transmission will now be optional. Buick states that the self-shifting unit will not hinder performance (well, except for that whole shift-on-your-own-terms thing), citing that the automatic-equipped Regal GS will sprint to 60 miles per hour in 6.7 seconds, just like manual-equipped cars.

Buick will release full pricing and availability for the 2013 Regal line later this year.