Cadillac Catera Vs. Lexus ES 300 Vs. Mitsubishi Diamante LS - Comparison Test - Engine

Like the Lexus, the Diamante has an interior styled with an eye toward sophisticated restraint. Devoid of extraneous gadgetry, the well-equipped Diamante LS offers several useful features. Steering-wheel-mounted audio controls will please frequency surfers, and the unique illuminated climate-control display has an expensive look to it, as well.

Some ergo-gripes popped up, however. Most of our drivers wished the Mitsubishi's front bucket seats had better lumbar support, and all agreed that the lumpy shape of the adjustable lumbar mechanism was a comfort blunder. The power seat controls are intuitively engineered but crowded tightly up against the door; the low-mounted audio controls require looking well away from the road during adjustments.

The tale of the tape reveals that the Mitsubishi is the leader in most measures of interior roominess. It has the widest cabin through the hips and shoulders, and has the most front legroom. Rear legroom is also generous. Despite claimed rear headroom good enough to rank it in second place behind the Cadillac and well ahead of the Lexus, real-life measures of rear headroom reveal that the Diamante's back seat has a hard time comfortably accommodating anyone over about six feet tall.

Light My FireFor this luxo-triad, V-6 powerplants provide the go-power, but each one varies in displacement and execution. Both the Lexus and Cadillac have 3.0-liter DOHC engines, but the Catera has its cylinder banks splayed at 54 degrees in the interest of narrowness, while the ES 300 has its canted a more conventional 60 degrees apart. Despite their many differences, both engines deliver 200 horsepower on the dynamometer. The Cadillac needs 6000 rpm showing on the tach to hit that figure, while the Lexus need only turn a more leisurely 5200 rpm. The ES 300 holds a substantial torque advantage over the Catera-214 versus 192 pound-feet, though the Cadillac develops its peak at a low 3600 rpm, versus the Lexus' 4400. Factor in the overall vehicle weights into this hail of numbers, and the Lexus holds a substantial seat-of-the-pants advantage (the Cadillac is almost 500 pounds heavier). The ES 300's powerful midrange snap and lighter load make it feel considerably more energetic-a sensation backed up in measured acceleration testing. The Lexus' 8.0-second dash to 60 mph is a half second quicker than the Cadillac's, which also trails by 0.4 second and 3.1 mph at the end of the quarter mile. The Catera is adequately powerful and comfortably capable on the road, but the Lexus is better.

Mitsubishi's Diamante bucks 3.0-liter normalcy with a much larger 3.5-liter SOHC V-6. The extra cubes mean more power, by any measure. Its peak pony count is 210 at 5000 rpm, and torque is a bountiful 231 pound-feet at 4000 revs. Although the Diamante weighs about a hundred pounds more than the ES 300, the extra engine-room urge keeps it right on top of the ES 300, with an 8.1-second 0-60-mph clocking and a 16.1-second quarter-mile time. A higher terminal speed (87.5 versus 86.9 mph for the Lexus) suggests that the Diamante's big engine hits its stride as the speeds increase.

Civility is at least as important as raw power in a luxury sedan, and all three in this group clear the bar in this respect-none with more grace than the ES 300's delightful powerplant, however. Nearly vibrationless, the Lexus engine makes only the muted sound of quality. Quick to rev and respond decisively, the V-6 works beautifully with its four-speed automatic to answer your acceleratory needs.

The Diamante's V-6 develops all the power you'd reasonably require-but it feels a bit unrefined. Able to chirp the front tires unexpectedly if you're exuberant with the gas pedal, it's normally smooth and quiet in operation, but seems to be occasionally let down by the electronically controlled four-speed automatic transmission. With uncalled-for hunting and occasional bouts of shift-shock, the Mitsubishi's driveline is noticeably less coordinated than the Lexus'.