By Greg N. Brown
It's easy enough to want a Mercedes-Benz S-Class. We'd gladly make room in our dream garage for one of the big luxurious sedans, but there's a problem: which one to choose? There were three different yet equally delightful models available in the US in 2006 and the line-up for 2007 is even richer, with the introduction of the powerful S63 AMG and the weather-beating S550 4Matic. Imagine if our stable were located outside North America: nine S-Class variants (not counting short- and long-wheelbase models) are offered in Europe, each one tempting in its distinctive but delicious ratios of performance, luxury and economy.
Our daydream decision hasn't been made any easier after driving two new versions. If one had to choose, the part of the brain that responds to the deeply luscious noises of a large-displacement V8 at full song would select the S63 AMG. However, the chunk of gray matter that monitors fuel prices would advocate the diesel-powered S320 CDI 4Matic. Helping avoid any bi-polar disputes in this fantasy is the unfortunate fact that the diesel S-Class is not slated for the US market-yet.
A six-cylinder S-Class, much less one sipping diesel fuel, may be an abomination to US buyers, but we think the S320 CDI 4Matic is as capable of handling real-world challenges as its gas-sucking stablemates and would be right at home on American roads. It pulls up and over mountains with an almost frisky ease, and cruises highways with the quiet, solid stability that has been a longtime S-Class trademark.
We note the huge disparity in engine output between the S63's 518 bhp and the CDI's 235 bhp. But because of the immediacy and efficacy of the turbodiesel's torque-its almost 400 lb-ft peaks at 1600 rpm-the S320 CDI is by no means left in the dust, especially when the road begins to snake and the newly revised 4Matic all-wheel-drive system does its job. This system is now fitted with a planetary-type center differential that permanently sends 45 percent of the engine's power to the front wheels and the rest to the rear. Traction issues are met with an integrated multi-plate clutch and all the familiar electronic aids.
Both cars emanate the security, exquisite engineering and sybaritic comfort of Mercedes' flagship, and both are chock-a-block with the requisite S-Class goodies, including Mercedes' spectacular Airmatic air suspension system. Both, however, do not deliver equally outstanding fuel mileage. The S63 AMG gets around 15 mpg combined, while the S320 CDI achieves a remarkable 27. It takes the S320 longer to reach 60 mph (about 7.3 seconds) than the S63 (about 4.4 seconds), but at optimum consumption, the diesel is able to run for more than 620 miles without stopping for fuel. Remind you of a certain tortoise and hare?
We've waxed long and lovingly about the AMG-designed-and-built 6.2-liter engine replacing the supercharged 5.5-liter V8, and the 518-bhp version in the S63 does nothing to change our minds. The car pulls away as though some external force had eliminated the normal drag of weight, air and surface friction, reaching the electronically limited top speed of 155 mph in a great swoosh of linear power that never lets up from the first press of the accelerator pedal.
Though not as hard-edged as its AMG-built CL63 two-door counterpart, the S63 nevertheless carves a fine figure through the twisties and is rarely upset by breaks in the pavement. Still, we can get through those corners about as quickly in the 4Matic diesel, and won't be stopping for fuel any time soon.
Power or economy, or a little of both? Maybe not having the choice is a good thing.
Prices have yet to be announced, but we're expecting the S63's MSRP to be close to the outgoing S55's base price of $117,000. Wanting is easy, paying for it is harder.