For the record, I can say that at Brickworld this past summer, it seemed that Cale's PF-powered locomotive could pull anything it wanted in the train pull contest. Now, based on Tony's video of the Allegheny, it looks like his engine can pull whatever it wants, too - Buick included.
In fact, with the benefit of the Power Functions motors, locomotives are now so powerful that pulling long consists of cars is becoming - dare I say - a tad dull. That means that trainheads are going to have to find something else to pull - such as each other. My thought is that we should create a new competitive event where Tony and Cale can duke it out tractor-pull style and figure out who gets the PF super-engine bragging rights, once and for all.
Since Cale and Tony have the world of steam engines well in hand, I'd like to switch gears to the electric realm and point out that Holger Matthes has posted a very nice Krokodil of Swiss design on Brickshelf. Not only that, but it uses the medium PF motors in the hoods for power, and it has an "eclectic" mix of the BBB medium wheels and the new wheels from the Emerald Night.
I know we've seen quite a few Crocodile engines, but HoMa's done a nice job with this one. It's brown, for one thing, and check out my favorite feature - the drive rods.
Steam engines aren't the only ones to have fascinating, moving drive rod assemblies. The PF motor appears to drive the wheels via a conventional geared arrangement, but the drive rods simulate the mechanism found in the real version of this Krokodil, where a motor would turn the cam seen in the above picture, which in turn would power the drive rods and then the wheels.
You can see more pictures of Holger's Krokodil here: