BMW M meets Mercedes-Benz AMG

Factory-built high-performance "special editions" are nothing new. The first undoubtedly was conceived many decades ago, when some manufacturer somewhere decided to offer a larger engine and bigger tires on an existing, economy-minded model. The original Hurst/Olds of '68 further developed the formula. Offering a high-output engine and a combination of options and model identification not available on a standard 4-4-2, the H/O was handbuilt in limited numbers and marketed via its strong tie to racing.

Nobody has better perfected the formula than BMW's M division and its AMG counterpart at Mercedes-Benz. Though each German marque's executions are anything but the same, the basic recipe is virtually identical: serious power upgrades, improved handling, better braking, high-zoot cabin upgrades, speed-rated rolling stock, and a hunkered-down look. Don't forget the image-enhancing and value-increasing limited build quantity, a meaningful motorsport connection and a commensurately beefed-up pricetag. Speed-and exclusivity-costs money. How fast do you want to go?

In military terms, opposing forces patrolling the same boundary lines are called "mirrors." As BMW and Mercedes-Benz compete at just about every level on a worldwide basis, it's no surprise that nearly every M machine has an AMG mirror (or is it the other way around?). BMW's new X5 4.6is is not, in fact, an official M model, though it was developed with most of the same values in mind. It's also critically important to make the distinction between these and aftermarket tuner cars. M and AMG are wholly owned divisions of their respective companies and are backed by considerable engineering expertise. Any of these exclusive products can be purchased, serviced, and financed at factory dealers and is backed by much the same warranties. These factors support the high demand and strong resale values that Ms and AMGs garner.

We felt it was high time we pit four pairs of them against each other to see if these mirrors are indeed direct reflections or not. Fasten your seatbelts: It's time to play M versus AMG.