For one thing, the 9-3 is built on the Epsilon platform, which was only shared with the Chevy Malibu in the United States. The Cobalt, on the other hand, was built on the Delta platform.
This means that the 9-3 is a “compact executive” vehicle while the Cobalt is a “subcompact”. When we parked a 2008 Saab 9-3 next to a 2009 Chevrolet Cobalt, we could hardly notice the slightly longer wheel-base. As a passenger, however, the difference is a bit more noticeable, though it’s not extremely profound. Even so, the 9-3 is often compared to the Cobalt.
For all my car nerds out there, it’s worth noting that GM extended the Epsilon architecture for certain vehicles, including the Malibu beginning in 2008. Some say that most of the new safety features and modifications to allow for all-wheel drive systems were courtesy of Saab’s engineering.
So, going back to the initial point, why do the Cobalt and 9-3 get compared so often, then? It’s mainly because they share nearly identical drivetrains: Ecotec four-cylinder engines matted to F-series transmissions. Interestingly, the development of the Ecotec engine lineup was carried out by an international team of engineers, from Opel in Germany, GM in Michigan, Saab in Sweden, and Lotus Engineering in the UK. In fact, Lotus did majority of the work, go figure.
In terms of performance, owners of the 2005-2007 Chevrolet Cobalt SS coupe with the supercharged 2.0-liter LSJ four-banger can swap the blower out for a turbocharger by using factory parts from the turbocharged 2.0 engines which were used by Saabs of the same era (though they’ll need components from the 2.2-liter L61 as well). This is just one of the many ways in which enthusiasts have gone on to refine their GM-built vehicles with Saab parts *wink*. Another notable example would be the F40 6-speed transmission, which is used in high-horsepower applications since it has proven to be much more stout than the F35 5-speed transmissions used in the SS trim-level Cobalts.
What about the Cadillac CTS? Well, the CTS utilizes an engine from GM’s global V6 family. If we look at the 2008 Saab 9-3 Aero sitting in the garage with the turbocharged 2.8-liter V6, we’ll see a lot of similarities between it and the 3.6-liter V6 that powered CTSs of the same year. It’s been theorized that one could pull the manifolds and turbocharger setup from the 2.8, install them on the 3.6, and turbocharge a CTS for significantly less than what an aftermarket setup would cost. If one could tune the Cadillac ECU via HPTuners instead of a third-party for the 2.8’s Bosch ECU, then the savings would be even more substantial. However, most of these conversations end with, “you’re better off just buying a V-series from the get-go, it’ll be cheaper and quicker in the end.” That said, this may no longer be the case given the value of these cars in today’s market, and the parts availability.
Note that we’ve only compared the 9-3 to other vehicles that were sold domestically here in the U.S., unlike its Opel and Holden counterparts. There are many more differences and similarities between Saab and other GM vehicles that we can discuss, but by comparing the 9-3 to just three of the other GM vehicles that it shared parts with, we can see how Saab managed to innovate and build cars that offered a satisfying driving experience–vehicles that were truly greater than the some of their parts.
Some would even go so far as to argue that Saab’s build quality matched Cadillac’s despite the difference in support from the General (I think they call this the ‘premium’ market now, and it’s what Buick and GMC have fallen into). Perhaps there is a lesson somewhere in there that we can all be inspired by.