Behind the Wheel - Chevy's test-bed Monte Carlo SS

Behind the Wheel - Chevy's test-bed Monte Carlo SS

Rick Poage

As the 2014 Corvette Stingray makes its debut, we are starting to see more and more relevance towards GM’s recent test-bed vehicles over the last decade. Once such example is the Monte Carlo SS pictured here (’06-’07), specifically, with its cylinder deactivation feature.

Originally developed in the early oughts, the technology was called Displacement on Demand, but further development led to the second generation and what we now call Active Fuel Management (AFM).  GM’s first applications were all Chevrolet…the Trailblazer/Envoy in 2005, the Impala and Monte Carlo in 2006, and finally in the 2010 Camaro SS debut (standard all automatics).

From Wikipedia:

In order to deactivate a cylinder, the exhaust valve is prevented from opening after the power stroke and the exhaust gas charge is retained in the cylinder and compressed during the exhaust stroke. Following the exhaust stroke, the intake valve is prevented from opening. The exhaust gas in the cylinder is expanded and compressed over and over again and acts like a gas spring. As multiple cylinders are shut off at a time (cylinders 1, 4, 6 and 7 for a V8), the power required for compression of the exhaust gas in one cylinder is countered by the decompression of retained exhaust gas in another. When more power is called for, the exhaust valve is reactivated and the old exhaust gas is expelled during the exhaust stroke. The intake valve is likewise reactivated and normal engine operation is resumed. The net effect of cylinder deactivation is an improvement in fuel economy and likewise a reduction in exhaust emissions. General Motors was the first to modify existing, production engines to enable cylinder deactivation, with the introduction of the CadillacL62 "V8-6-4" in 1981.

In driving the Monte pictured here, you can definitely see the fuel economy improve while in 4CYL Mode, but unfortunately, that’s not very often.  It’ll come on easily during lift-off, cruise control, or any downhill coast…but the minute you touch the gas pedal, you’re back in 8CYL mode.  Several staffers also commented on the torque-steer, which honestly, would have been a significant achievement if the engineers had figured that out.  The ride is surprisingly really nice at highway speeds; the quietness in the cabin is near Cadillac grade. The low profile tires and revised sports suspension (SS only) combine to minimize body roll and bolster confidence In the corners…but we recommend a little practice before you send in your entrance fee to the next Grand Am race.  With 303hp on tap, this car gets up and GOES – thank goodness for the traction control which works well to monitor the wheelspin and provide prodigious straight-line performance.  We can almost guarantee that you’ll surprise the next Fox-Body 5.0 you pull up next to.

Comfortable seating, great dash layout, steering wheel controls, and a console shifter makes the car fun to be in. XM Radio and OnStar too.  The leather surfaces are absolutely perfect in front and back.  And, how about that back seat?  Plenty of room for four adults or a family of five, this Coupe is a serious contender to any of the four-door-sedans you might have been looking for in the past…except with much better styling and the distinction of being made in America by Chevrolet.

All of this makes the “Monte SS” a rather significant player in the long run…especially after the announcement of the LT1 AFM system debuting in the new Stingray.  It certainly gives renewed credibility, and in our opinion, more value to these cars…after all, they could’ve abandoned the technology altogether, but they didn’t…AFM had significant enough benefit to secure its place as a primary feature nearly four years later in the all-new Corvette!  That’s saying something! As this becomes more prevalent in GM’s line, we predict that more and more aftermarket software upgrades will appear on the market.  This, of course, could make these cars even more valuable in the future?  Who knows, the Monte Carlo SS could be the first “open-platform powertrain” to ever hit the market? 

Brought to you by the General himself, who’da thought?