Chevrolet Volt with 20s

Our spy photographers managed to spot something curious (and decidedly hilarious) recently. General Motors has been busy testing what would appear to be Chevrolet Volt models with massive 20-inch wheels and tires in place of the low-rolling resistance pieces on the stock plug-in.

Why? Guesses are slim at the moment, but one hypothesis is that this is actually our first glimpse at a Cadillac Converj test mule. That vehicle will make use of an altered version of the Voltec drivetrain found in the Chevrolet, albeit bolted to flashier wheels. The luxury hybrid has been an on-again-off-again affair for General Motors since the concept first rolled across the stage at the 2009 Detroit Auto Show.

Last we heard, the Converj is on track for launch in either 2013 or 2014. If true, now would be the time to begin working out any engineering bugs on the rumored Voltec 1.5 system. With luxury buyers more willing to hand over stacks of cash for new technology, the Converj could make quite a bit more sense to buyers than the Volt. Or bolting chrome dubs to a hybrid, for that matter.