Here's a freaky one for you.

We took this 2007 Mercedes-Benz E550 to the test track on July 13. It was a Thursday, and it began like any other day. Just as we always do, we arrived around 8 a.m., set up the ol' radar gun and began to make passes down California Speedway's new drag strip. No big deal, just another day earning the bacon.

Then it happened. The Benz reared back and blitzed the quarter-mile in 13.5 seconds. Holy Stephen Hawking Batman, 13 seconds on Thursday the 13th. Kinda makes your skin crawl, doesn't it?

OK, so maybe it's not that weird. Alright, it's not weird at all. But a 13.5-second quarter-mile is freaky quick for a car in the luxury midsize segment. Just a few years ago, an E55 AMG accelerated at that rate and was one of the quickest sedans in the world. To use a technical term, the 2007 E550 hauls ***.

The latest and greatest
Maybe we shouldn't be so surprised at the E550's thrust. It's essentially a 2006 E500 fitted with the same all-aluminum, normally aspirated 5.5-liter that debuted in the 2007 S-Class. It's the largest and most powerful engine in the midsize luxury class and it's a technological masterwork, with double overhead cams, a two-stage intake manifold and variable valve timing for its 32 intake and exhaust valves. Peak output is 382 horsepower at 6000 rpm and 391 pound-feet of torque at 2800 rpm.

You better be impressed. That's 80 hp and 52 lb-ft more than the 5.0-liter V8 it replaces. It also makes the E550 more powerful than that E55 (sold from 1999-2002) we mentioned a minute ago. That car's 5.4-liter V8 was rated at 349 hp at 5,500 rpm and the same 391 lb-ft of torque at 3000 rpm.

Benz is backing the engine exclusively with the same 7-speed automatic it's implementing across its entire lineup, and the combination is sublime. Around town the 7-speed automatic is always in the right gear, and the big V8's torque curve redefines flat. This is not a high-strung drive. There's always power on tap, but the engine speed is usually closer to idle than its 6500-rpm redline. That is, of course, until you lay into it.

Bye, bye baby
Nail it from a dead stop and the E550 hits like Tyson in his prime. At full throttle, the rear-wheel-drive E550 treats with a melodious V8 bellow, firm, right-on-redline upshifts and great forward thrust. Zero to 60 mph is a 5.2-second sprint. Just over 8 seconds later the quarter-mile has been covered and the E550 is traveling at more than 104 mph.

That makes the new Mercedes E550 quick enough to leave a long list of high-zoot performance cars in its wake. Cars like the Pontiac GTO, Subaru WRX STi, Ford Mustang GT and Nissan 350Z all eat the E550's rather expensive dust, which means this leather-lined, 4000-pound sedan can hold its own at any test and tune night in the country.

Although the traditional clientele of Mercedes-Benz has always been heavy into drag racing, Mercedes didn't create the E550 to rule your local grudge night. Its purpose is to outrun its rival German sedans, the BMW 550i and the Audi A6 4.2. And it does.

The same week we sampled this E550, our garage housed a 2007 BMW 550i with a 6-speed manual transmission and a 2006 Audi A6 4.2 S-Line. All three cost within a grand of each other and all three went to the test track on the same day. The Benz blew them both out into the weeds, especially the heavier Audi, which was nearly 2 seconds off the E550's pace. The BMW's times of 5.6 seconds to 60 mph and a 13.8-second quarter-mile are certainly quick, but a 550i equipped with an automatic is sure to be slower.

More money and tweaks
Aside from sick quick, the E550 is traditional Benz, which is to say solid, luxurious and expensive. Base price is up $600 from last year to an even $59,000, and our Flint Grey example carried a $65,815 as-tested price because it wore the Premium II Package that added a DVD navigation system, heated and cooled front seats, push-button start and other sundries.

Buyers can choose between two flavors of E550, Luxury and Sport. Our test car was a Sport, which added black inserts to the grille, chrome detail around the foglights, 18-inch 10-twin-spoke wheels, blue tinted glass, LED taillights, a lowered suspension, dual exhaust, cross-drilled front brake discs and silver 4-piston front brake calipers. On the inside, Sport models get white-faced gauges, black bird's eye maple wood trim and matte chrome instead of wood on the leather shift ****.

That shift ****, along with a new 4-spoke steering wheel, both lifted from the SL550 roadster, are also new to the E-Class. They're an improvement, as are the re-formed side mirrors and restyled wheels. The new bumper covers and restyled headlamps, however, are a little fussy for our taste.

Mercedes has also made active front head restraints and its PreSafe system standard on the E-Class. PreSafe can anticipate an accident and take action for the driver, first by tensioning the seatbelts and moving the passenger seat to a more favorable crash position. If the vehicle skids, it even closes the sunroof in anticipation of a rollover.

Well enough alone
Mercedes limited chassis revisions to a light retuning of the adjustable Airmatic suspension system and a 10-percent quicker steering ratio. The results are a very heavy sedan that feels a little lighter on its feet.

Still, this sport sedan is not as athletic as its rivals. Its test track performance numbers — 0.80g on the skid pad, 63.5 mph through the slalom and 126-foot stopping distance from 60 mph — are very good, but not great. Both the 550i and A6 4.2 S-Line outhandle and outstop the E550, but the more relaxed ride and handling compromise of the Mercedes feels better at anything short of the most fevered pace.

Even in the stiffest of its three suspension settings, the Mercedes is sprung more softly than the BMW or the Audi, putting a higher premium on a smooth ride than ultimate agility. Its stability control can't be completely shut off anyway, so this is not the car for a hard run through the hills. No, the E550 is happiest in the city or out on the open road, where its quick reactions and endless torque make it a truly great drive.

Better, stronger, faster
Say what you want about Mercedes-Benz, it's a company that understands how to make a great car greater. You add motor, stupid! a lesson more than a few car companies still need to learn.

With the E550, Mercedes has improved upon an already wonderful machine, a car we already had the hots for. And it took exactly 13.5 seconds to convince us that Mercedes-Benz has done it again.