Mercedes-Benz 3.2L SOHC V-6Although WAW is just 6,000 miles (9,650 km) into its extended evaluation of the Mercedes-Benz 3.2L SOHC V-6, a Ward's Ten Best Engines award winner for two years running, tougher duty could scarcely be imagined.

The Mercedes V-6 powering the ML320 sport/utility vehicle (SUV) was delivered just in time to encounter Detroit's worst snowfall in decades - accompanied by cruelly chilling temperatures.

Thus the ML320 logbook's early entries expound on the ability of the all-new V-6 - the first 6-cyl. vee engine ever for Mercedes - to start immediately and settle into an even idle at truly indecent temperatures. We think this in part may be attributable to the dual-sparkplug design, making for a combustion chamber that doesn't want for a clean burn of the intake charge.

Drivers new to this engine are impressed by the 3.2L V-6's capacity for motivating the 4,387-lb. (1,990-kg) ML; midrange urge, in particular, is markedly better than for most any other V-6 SUV we can name. Only low-speed acceleration is sometimes wanting, as the otherwise unreproachable 5-speed automatic seems to sometimes mitigate against sharp, positive and quick kickdown into a lower gear.

The upgrade for all 1999 M-Class SUVs to Mercedes' Electronic Stability Program (ESP) brings an electronic drive-by-wire throttle to the 3.2L V-6. Yet the ML320's throttle action feels as heavy as it always has in a Mercedes - despite the fact there's no physical connection between the accelerator pedal and the engine. A hindrance sometimes, but nonetheless a comfort to current or previous Mercedes owners.

The drive-by-wire throttle yields satisfyingly stable cruise control that never wavers from one's selected speed. And it's virtually a requirement for link-up with ESP, enabling the stability control system to do an astounding job in correcting understeer or oversteer - particularly on icy or snow-covered surfaces.

So far, the 3.2L V-6 has delivered a respectable, if not scintillating, 18 mpg (13L/100 km). This economy figure is about what's expected of a two-ton SUV and is slightly better than the fuel-efficiency we've observed in similar-sized V-6 SUVs.

The engine also is equipped with Mercedes' Flexible Service System, a sophisticated watchdog that monitors oil quality and quantity, alerting you for an oil change or top-off only when necessary, based on your driving habits. Mercedes says the minimum change interval with FSS is 10,000 miles (16,000 km), so there's no scheduled maintenance yet to report.

Otherwise, the 1999 ML320 initially impresses as built to a high standard, with a tight, mostly friendly interior that's rattle-and-squeak free. Our only real complaint is a distinct lack of volume in heated air that can be directed to the footwells, a situation we'll have analyzed at the ML320's first service. o

Nissan VQ 3L DOHC V-6

Ah, the subtle package. The Nissan Motor Co. Ltd. Maxima and its superb 3L DOHC V-6 don't engender the sort of fuzzy feelings that drive buyers to Accords and Camrys - and we don't understand why. There isn't a driver who comes back after any time in the Maxima who doesn't gush with praise for both the car and the VQ engine's rip-snort-with-refinement.

All WAW testers say this duo is demonstrably more entertaining than any V-6-toting Accord or Camry. And Nissan bandwagon critics say the Maxima looks dull, but it's no more prosaic than its rivals.

The VQ's throttle response is exhilarating, its refinement without peer - 6,000 rpm in third gear is almost relaxed - and even its fuel economy can't be faulted. It's a 3L V-6 that, when hard on the throttle, gives sports cars something to consider.

Totally unrelated to engine operation, the Maxima's power steering rack seals went south, a matter fixed under warranty. Sharp readers may notice a jump in our scheduled-maintenance cost: that's because we parted with the Maxima long enough to grab an early 30,000-mile (48,000 km) scheduled service that included non-everyday items such as a radiator flush/fill, changing of gearbox lubricant and new wiper assemblies. And replacing a broken antenna mast set back WAW $83, which shows up in the non-scheduled maintenance portion of the accompanying spec box.