When we first drove the new Mercedes ML320 luxury SUV in 1998 we had high expectations. After a bone-jarring trip over some backcountry washboard roads we thought the new ML was going to come unglued. This was about the time of the Mercedes/Chrysler merger. We got out to check the badges to be sure we weren't driving a sixties Dodge Powerwagon.

Over time ML class quality improved, but it still fell short of other Mercedes. Given our less than enthusiastic take on previous ML models, we were very pleasantly surprised with the all-new 2006 Mercedes ML500 and ML350. These are Mercedes! Everything about the new ML500/ML350 is better than the old ones.

The 2006 Mercedes ML500 is bigger, more powerful, better looking and far better built than the previous models. There's a family resemblance, but the new body looks much smoother and better proportioned. It looks substantial and powerful. When you're paying Mercedes money you don't want to be mistaken for a Kia Sorento.

Interior space, comfort and most of all, quality are vastly improved for 2006. We expect Mercedes interiors to surround us in luxury and comfort. The handsome ML500 interior does just that. The front seats are outstanding. The rich leather seats are highly adjustable. Front legroom is of the stretch-out variety so long trips are a pleasure. The super thick polished wood and leather steering wheel is a tactile delight.

The ML500 accommodates five adults easily. The floor hump is low so adults can use the middle rear position, although it's not padded as well as the outboard positions. There isn't a third row seat as before, but that small seat wasn't very useful. The split folding second row seats lay flat for ample cargo capacity.

Engine size is a major difference between the ML500 and ML350. The 3.5-liter V-6 in the ML350 seems more like a V-8 than a V-6. It has 268 horsepower and 258 lb-ft of torque. The 5.0-liter ML500 V-8 is a wonderfully smooth engine. It's rated at 302 hp and 339 lb-ft of torque. Key to the excellent performance of both engines is a 7-speed automatic transmission. There's a gear for every occasion, so engine power is optimized. On mostly highway trips we exceeded EPA economy estimates for both MLs. EPA ratings are 16/20 and 14/19 (ML350/ML500). We got 24.6 and 20.4 respectively.

The new unibody construction and longer wheelbase give the Mercedes ML500 a considerably more car-like ride. Our test ML500 had the optional Air Suspension Package. It allows the driver to adjust the suspension for varying conditions and as such provides an excellent ride in all situations.

We've gone off-road on very muddy trails in the ML500 and it handled all the terrain types we encountered. Both MLs are competent off-highway vehicles, but the vast majority of ML owners will use them strictly on paved roads. Whether driving on or off road the Mercedes ML500 is loaded with sophisticated handling/braking/safety technology to protect its occupants.

Whines: We didn't figure out the annoying door open warning beeping system so we got in and out very quickly. The speedometer on the left side was partially blocked by the steering wheel, although there is a central digital readout. Audio system controls aren't very intuitive. The usual gripe about all Mercedes' is that the cruise control lever is in exactly the wrong place and is easily engaged when meaning to signal for a left-hand turn.

Bottom Line: Forget anything you might know about the previous generation Mercedes MLs; the 2006 ML500 and ML350 are totally different, immensely improved luxury SUVs. They're solid, well built, comfortable, secure and a pleasure to drive.