And now the "V" designation is tacked onto a pair of more luxurious models – the XLR-V and the STS-V.

The "normal" XLR and STS are fine cars as they stand; the "V" versions are not for the normal businessman, commuter, or faint-of-heart driver. They take Cadillac’s best Northstar V8, strap on a supercharger, and become a blur in an instant at the touch of the gas pedal.

In a whirlwind introduction that started in Washington, D.C., and continued later in California, the nation’s media got a whirlwind opportunity to drive the new Escalade – Cadillac’s overwhelming new version of its luxury-SUV segment leader – along with the XLR-V and STS-V.

The East Coast session started at the Mandarin Hotel in Washington, D.C., and allowed us a lot of spirited driving into the rolling hills and challenging roadways of Virginia. We saw freeways, two-lane rural highways, and along the way we drove past splendid old villages, including some historic wartime settings.

The cannons still stand ready on the hilltop at Manassas, but we were past them in a flash.

The Escalade review will have to wait, because the XLR-V and STS-V command attention first. These long-rumored and long-awaited variations of Cadillac’s sports car and midsize sedan can be spotted by their mesh grilles, similar to the CTS-V treatment, and sharper eyes will detect a few exterior scoops and trim items, and special wheels, but the primary appeal of both cars is what’s within the boldly contoured outer shell.

Both cars were thoroughly redone to firm up the housing for the new power, which bristles every time you touch the gas, and the cars themselves never lose their poise and class no matter how hard you hammer the gas.

Cadillac has been the shining light of luxury at General Motors for most of a century now, and while there have never been more luxurious vehicles wearing the Cadillac wreath, Cadillac also is poised to lead the whole corporation into the high-tech future.

The XLR-V and STS-V are the strongest indications yet that Cadillac can combine technology, performance and luxury into a single vehicle. Or two distinctly separate vehicles.

Both cars start with the 4.6-liter Northstar V8 engine, cut back to 4.4 liters, and then reworked internally to handle a supercharger. The supercharger is a device that requires some power, in this case, about 15 horsepower, and it dramatically increases power by compressing and force-feeding a blast of air into the intake, sucking great quantities of gasoline with it.

With the RPMs coming on much more forcefully, every part of an engine is strained by supercharging it, so Cadillac’s engineers reinforced every element of both engines – which are surprisingly different from each other.

While they were at it, chassis engineers also reinforced every joint and connection to further assure smooth application of all that power.

The larger STS-V sedan has a different, deeper-set version of the supercharged 4.4, with 469 horsepower and 439 foot-pounds of torque, making it the most powerful Cadillac vehicle ever built. It is capable of flinging the quite-heavy sedan from 0-60 in 4.8 seconds, and reaching a top speed electronically governed at 155 miles per hour.

The XLR, which is built on the same platform as the new Corvette, and in fact had the platform first, is lighter and smaller than the STS, so its version of the engine had to be streamlined. It is smaller, shorter in height, and "only" produces 443 horsepower and 414 foot-pounds of torque. Its size and sizzle makes it a 4.6-second screamer from 0-60, and it also has a limit of 155 mph.

The old adage, promoted most prominently by General Motors, is that "there’s no substitute for cubic inches" when it comes to developing power. Cadillac now proves that there IS a substitute for massive displacement, and it is technology.

But it is costly to create.

The STS-V starts out at $77,090, very Mercedes AMG-like, or BMW M-Class like. But it comes without a single option. The only selection a customer can make is a "sunroof delete" to eliminate the power glass sunroof, but there is no discount for doing that.

The XLR starts with a more expensive vehicle and is even more exotic, so the XLR-V starts at $100,000. A nice, round number, to say the least.

General Motors earned its status of No. 1 automaker in the world while it stubbornly held fast to low-cost/high-return products, which means making dated technology work in modern times, all the while building large and larger truck-based vehicles that command large and larger prices – and revenue for GM.

Most of the rest of GM seemed determined to squeeze another horsepower out of pushrod technology, but Cadillac engineers got the green light to go high-tech, and built the dual-overhead-camshaft Northstar V8.

At a comparatively compact 4.6 liters, the Northstar was able to outrev and outrun much larger pushrod engines.

More recently, Cadillac came up with the 3.6-liter V6, an even more advanced dual-overhead-cam engine with variable valve-timing that is capable of being tweaked to the level of a world-class powerplant, against the best that Japan or Germany can muster.

When Cadillac redesigned its entire line, it built the CTS entry-level sedan, the XLR retractable-roof sports car, the SRX crossover SUV, and changed the name of the Seville to the STS and the DeVille to the new DTS. The brilliant 3.6 V6 was inserted as the base engine in the CTS, STS and SRX, and the proprietary Northstar V8 was the only engine in the XLR and DTS, and the only upgrade in the STS and SRX.

Luxury cars tend to veer either toward comfort/luxury, or performance/luxury, so Cadillac, having proven a hit with the sharply chiseled, edgy design of the whole new line, decided to venture into the performance/luxury market.

The CTS, which is a very good car in basic form with the "high-feature" V6, had the Corvette V8 installed. While extremely powerful, the Corvette engine even in the new Corvette is a high-tech version of the aging pushrod, or fixed cam-in-block design, with 6 or even 7 liters of displacement.

The CTS-V has attracted a whole new and younger clientele to Cadillac showrooms: Compared to the garden-variety CTS, the CTS-V attracts buyers 9 years younger, 26-percent more college educated, and with $72,000 more in annual earnings than other Cadillace customers.

The new look of Cadillac is implemented by Cadillac product director John Howell, who said he is the most veteran member of Cadillac’s executive staff – and he has been at Cadillac only five and a half years. The youthful approach to performance/luxury has lifted Cadillac past Lincoln and Mercedes to where it currently resides, in third place with 235,002 sales in 2005, behind only Lexus (302,895 vehicles sold) and BMW (266,200).

But Cadillac is not resting on its laurel wreath."With success can come conservatism," said Howell, "but not at Cadillac."

Howell described Phase One of the "Cadillac Renaissance" as a five-year plan to renew styling, performance, new products and public perception. Phase Two starts now, and is aimed at establishing world-standard levels of performance and refinement. The CTS-V may have caught the automotive world by surprise, but the XLR-V and STS-V are something different – aimed at taking on "the best from BMW, Mercedes or Audi," said Howell.

Greg Prior, the chief engineer on the Northstar V8, is an overhead-cam guy who had to win a few internal battles before being allowed to develop the V engines. "We’re aware of our heritage, but we realize it doesn’t mean a thing if you don’t follow up on it," he said.

In the STS-V, 90 percent of the torque plateaus from 2,500-6,100 RPMs, and in the XLR-V, the torque peak remains from 2,200-6,200. Prior gave a quick explanation of the upgrades required for the two new cars, and much of it was in engineer-eze. In summary, he declared the obvious, that these engines are far more than just a supercharger bolted on to an existing engine.

New material and refinement were needed to strengthen pistons, heads, water-jacket, everything, to get ready for extreme dosages of revs, power, and heat. Built at a new facility in Wixom, Mich., one engine-builder does the actual assembly of each engine.

The governed top speed of 155 is, obviously, still excessive, but it was interesting to tease the pride of the STS-V and XLR-V engineers by mentioning that the more boy-racer CTS-V has an ungoverned limit of 163.

The explanation was that the CTS-V was faster because it is more race-track oriented. With considerable pride, however, one engineer admitted that if ungoverned, the STS-V had attained 170 mph.

Then the XLR-V engineer said his car had hit 173. Score another for technology, and don’t worry about getting to the shopping center before closing.

On the STS-V, the six-speed automatic transmission is a new device with a two-clutch arrangement for the rear-wheel-drive vehicles. Suspension components were all revised as well, with increased cornering and handling firmness, and quicker steering feel.

All sorts of exotic parts are included on the STS-V, including antilock brakes, traction control and Stabilitrak. The transmission in the STS-V has a sport mode, which allows you to shift off to the side and tap it up or down to shift manually. It is computer controlled for quicker response, and it automatically matches revs on downshifts, and inhibits unwanted downshifts when cornering.

Driving the STS-V is a treat, and it handles with a nimble precision that sets it above the normal and very competent STS, and up there with the best of the world’s luxury/performance cars. Right on, Cadillac. The leather and wood interior trim is impressive as well.

Switching to the XLR-V, and there are a couple of exclusive new touches. It has nearly perfect 50-50 weight distribution on the front and rear axles, and, like the STS-V, it has been lowered and refined for the extra power.

There had been some critics of the XLR steering for being too imprecise, so more effort has been dialed in. The steering is much quicker, and the suspension has high-performance versions of the electromagnetic shock absorbers that stiffen five times faster than conventional shocks.

The exhaust, if you can imagine, has computer controls to open up for less restricted airflow, and noise, at high revs.

A key feature in the XLR-V is the ability to drive it normally and impressively with the shifter in "D." But shift it into manual mode, and two amazing changes take place: the shifter responds much more quickly, and the suspension and steering both firm up for more aggressive driving.

My driving partner left it in D and we were both impressed. I switched it to the manual mode and the car’s precision was remarkable. At one point, we were driving along a two-lane highway, with a couple of engineers behind us in an Escalade.

As an experiment – in the interest of science, you understand -- I hit the gas on a clear stretch and immediately reached a fairly high rate of speed. Then, to try to detect a difference, I shifted to the normal D setting.

Immediately I noticed a less-precise feel to the steering, and didn’t want to feel a commensurate softening in the suspension. I immediately shifted back to manual, and welcomed the firmer steering feel.

Later, I told one of the engineers we had left in the distance, that on that particular stretch of road in the normal D setting, 90 mph was far too fast; but in the manual setting with firmer suspension and steering, 90 might not have been fast enough.