They may be politically incorrect, environmentalists may hate them, but Detroit's full-size SUVs remain shameless in their supersized ostentation.

The 2007 Navigator is even bigger and heavier than its predecessor, actually putting it over a weight threshold that, paradoxically, exempts it from government fuel-economy testing. On top of which, an even heavier new "stretch" Navigator L adds 38 cm of body length to more-than double the cargo space behind the third-row seat.

The new Nav's backbone is a new and stiffer frame, with a new 5-link independent rear suspension. The old truck was almost shockingly agile for its size, and the new one is likely even better.

The '07's Achilles Heel is its powertrain. Carried over basically unchanged from '06, the 300-hp, 5.4-litre V8 is comprehensively outpowered by the new Escalade's 403-hp 6.2-litre unit. To wit, 0-100 km/h times of 8.9 and 7.0 seconds respectively.

On the other hand, the Navigator is quiet -- the engine is way more refined than Escalade's when it's working hard. In fact, Lincoln claims its engineers actually beat their own targets for interior quietness (all the better to hear the available, 14-speaker THX audio system).

The sumptuously appointed interior contains eight seats, with a standard power-folding third-row bench.

Quiet, luxurious, spacious, comfortable -- a true Lincoln

Oversized, ostentatious, underpowered