Mercedes coupe looks much like the 300E but is substantially redesignedMercedes-Benz's 300E has long been lauded as one of the best midsize sedans on the road. So why not just fill in its two rear doors and have one of the best coupes on the road?

Because that's not the way Mercedes does things.Instead, the German luxury carmaker has seen fit to substantially redesign its 300 series sedan to come up with a midsize coupe, dubbed the 300CE.

While remarkably similar to the sedan at first glance, the 300CE is over 3 inches shorter, and rides a 106.9-inch wheelbase, vs. the sedan's 110.2-inch stretch.

Its windshield is set at a more rakish angle than the sedan's, while its longer doors have a true hardtop styling with no frame surrounding the glass. Its interior is also similar, sharing the sedan's well-designed dashboard and the full range of luxury amenities expected in this marque.

A driver's side air bag is standard fare, while a passenger-side air bag that displaces the glovebox is offered as a $615 option.

The coupe version also has electric arms that unobtrusively serve front occupants their shoulder belts before retracting. Its soft leather seats are electrically adjustable and supportive up front. Rear seat space, however, is at a premium, especially in leg room because of the 300CE's shorter wheelbase

Throughout its cabin are wood accents so polished they look fake, even on the roller top desk openings covering the front and rear consoles. To underscore Mercedes' attention to detail and safety, all wood panels are laminated onto an aluminum honeycomb mesh to ensure the wood breaks properly in the event of an accident.

There is even a first aid kit stowed in the rear package shelf, and a dashboard button that allows drivers to automatically drop the rear headrests for improved rear vision.

While both the coupe and sedan share the same basic suspensions and other underpinnings, the 300CE is 190 pounds heavier (3,315 vs. 3,505). Much of that gain is dedicated to reinforcing the chassis to compensate for its pillarless roof design.

To overcome that weight penalty, Mercedes has beefed up the 300CE's engine for 1990. It gets a mildly detuned version of the same 24-valve engine powering the carmaker's new and considerably more expensive 300SL roadster.

Expensive is rather a relative term in this case, since the 300CE evaluated cost $57,065 as tested, counting a $250 destination fee and passenger-side air bag.

Its inline six-cylinder displaces 3.0 liters, and is mated to a silky shifting 4-speed automatic, the only gearbox offered in the 300CE. Generating 217 horsepower at 6,400 rpm - up 40 hp from 1989 - it reaches 60 mph from standstill in about 8.5 seconds and can nearly triple the national speed limit.

The consequence, however, is a $500 gas guzzler tax all 300CE owners must now pay because of its EPA fuel mileage rating of only 17 city/21 mpg highway. Unleaded premium is required, as with all gasoline-engined Mercedes cars.

While very respectable performance for a straight six, most owners will never even consider the 300CE a slalom champion, instead enjoying this car for its silent operation, solid feel and impeccable fit and finish.

In fact the 300CE's smooth highway performance at first masks its power, giving the sensation one is traveling slower than believed.

The 300CE's suspension smooths out most road irregularities, while its double firewall keeps engine noise at bay. Yet its chassis, steering and Michelin MXV tires still telegraph the needed degree of contact with the pavement, and its disc brakes bring this coupe to a stop without fanfare, even without using the system's anti-lock circuitry.

The 300CE feels as heavy as cars weighing 500 pounds more, giving one the impression it is virtually unflappable - until one really starts pushing it hard into the corners, where its relatively narrow tires seem to be the weak link.

But there is little doubt that those who plunk down roughly $57,000 for this Mercedes will ever drive that aggressively, or wish for anything other than what the 300CE is - one of the most competent midsize coupes on the market today.