Mercedes Benz E500 can be equipped with Distronic, a version of cruise control that uses radar, as well as throttle and brake, to follow a vehicle at a preset distance.

The five-passenger luxury sedans have much in common, including suspensions, brake systems, and dimensions, as well as a knack for causing car envy in the neighborhood.

The biggest difference is under the hood. The E320 has a 3.2-liter V6 with 221-hp and 232 lb-ft of torque at 3,000 to 4,800 rpm. The E500, on the other hand, sports a 5-liter V8 that generates up to 302 hp and 339 lb-ft of torque at 2,700 to 4,250 rpm. While the E320 has more than enough power, the extra 80 or so horsepower makes a big difference in the 3,800-lb E500. Passing, merging, and uphill climbs are a cinch, but avoiding the law becomes a matter of luck and self-discipline.

Both models channel engine power through five-speed automatic transmissions with Touch Shift and logic that adapts to the driver's style. Touch Shift is the Mercedes-Benz version of clutchless shifting, which can be found in several higher-end cars, but I'm not sure anyone uses it.

The suspension and steering, which handle twisting roads and curvy hills with aplomb, are adapted from the company's S-Class cars. Up front, a four-link design employs spring links, torque struts, and upper wishbones to do an admirable job of smoothing out the bumps and potholes on highways and back roads. The back end has a five-link suspension with gas-charged shocks, four-stage variable damping, and computer-controlled air springs. The driver can choose damping settings that range from maximum comfort to "sporty."

Both cars are crammed with electronic goodies, full-featured sound systems, and comfortable accommodations. One of the nicest features is the Panorama roof. It gives riders a totally transparent roof with only a support member crossing from one B-pillar to the other. Safety hasn't been ignored either. Window air bags and belt tensioners go into action if the car senses an impending rollover. Electronic brakes are said to provide faster, more sure-footed responses. And Tele-Aid uses a dedicated, crash-secure cellular line to automatically call for help if a belt tensioner or air bag deploys. Prices start around $48,000 and $57,000 for the E320 and E500, respectively, and go up from there as options are added.

- Stephen J. Mraz