At first glance, the BMW X5 3.0i and the Jaguar S-Type 3.0L have little in common except for the size of their engines.

The X5 is a luxury sport-utility from a German automaker. The S-Type is a luxury sedan from a venerable name in British auto making that's now owned by Ford Motor.

In fact, each even employs a different engine configuration, with the BMW getting the expected in-line version of its cylinders while the Jaguar employs a V-6.

Yet each represents an attempt by its maker to stretch the availability of a new model. In this case, the six-cylinder versions of these vehicles make them not only less powerful but also much cheaper than their V-8-bearing siblings.

The X5 4.4i with its 282-horsepower V-8 sells for $50,045 with destination charge. The X5 3.0i that we drove with its 225-horsepower in-line six sells for $39,545.

The S-Type 4.0L with its 281-horsepower V-8 sells for $49,950 with destination charge. The S-Type 3.0L that we drove with its 240-horsepower V-6 sells for $44,250.

In these troubled economic times, even luxury car buyers think twice when making $5,000 or $10,000 decisions. Let's see what they get for their money.

Jaguar S-Type 3.0L

It didn't take the S-Type sports sedan long after its May 1999 debut to become the bestselling Jaguar in the United States. A price much more affordable than previous Jaguars and the car's gorgeous exterior proved an irresistible draw to many buyers.

With its four round front lights and oblong-shaped grille, the S-Type is instantly recognizable. Its body is contemporary and well-proportioned, and seems far removed from the ancient shape of the XJ sedan.

On the inside you'll find the requisite leather and wood, both looking just a bit more elegant than in some competing luxury models.

The biggest differences, obviously, in the 4.0L and 3.0L versions of the rear-wheel-drive S-Type are under the hood and on the road.

The 32-valve, dual-cam AJ-V8 found in the 4.0L has been around since 1996. It produces 281 horsepower and 287 foot-pounds of torque in the S-Type. It's a fast and potent motor and one that gives a Jaguar the racy feel it deserves.

The 3.0-liter AJ-V6 that arrived new with the S-Type in 1999 is Jaguar's first production V-6. At 240 horsepower and 221 foot-pounds of torque, it is smooth and sophisticated. But, at least when compared with the whomping good V-8, it feels a little unspirited on the road. Perhaps that's because less than 100 pounds separate the two versions of this car. That means the V-6 has to move nearly the same amount of weight with much less power. Jaguar's own performance numbers reveal that while the 4.0L gets from 0 to 60 mph in 6.6 seconds, it takes the 3.0L 8.0 seconds to reach 60 mph.

In the end, once a few options are added -- our nearly $50,000 test car came with a $2,000 navigation system and a $3,200 memory/weather package with moon roof, heated seats and other features -- the S-Type 3.0L gets pretty expensive. At that price, the six-cylinder S-Type is no bargain compared with similar models offered by BMW, Lexus, Volvo, Acura and others.

BMW X5 3.0i

In contrast, this new-for-2001 version 3.0i of the X5 sport-utility seems like more of a bargain. Perhaps it's the $10,500 sticker flicker between it and the 4.4i V-8 version. Perhaps it's the great goodness of the new aluminum in-line six powering this all-wheel-drive car-truck.

Or perhaps it's because BMW includes almost all of the good stuff in this cheaper model. That includes safety features like dynamic stability control and the head protection system, which can help keep you from crashing and cushions your noggin in case you do.

In terms of performance, a 4. X5 with an automatic transmission goes from 0 to 60 mph in 7.5 seconds while a 3.0i X5 does it in 8.6 seconds. The 3.0i weighs 256 pounds less (or 309 pounds less if you pick the X5 3.0i with the manual, a transmission choice that isn't available on the 4.4i.) On the road, both versions have tight, precise rides -- which you'd expect from a BMW but perhaps not from a sport-utility.

In this case, a cheaper price makes the X5 3.0i a better choice for many buyers.