I’m puzzled why X-308 owners would try to modify a car that was meant to do X, into a car that does Y.

To end up with a car that accelerates to the max — giving low 0-60 and 1/4 mile times — makes sense if you’re starting with a Mustang GT or a Honda Civic Type R. Their manufacturers designed them for this kind of duty and outfitted them with the beefed-up hardware that could take the punishment of bottom-end drag-racer acceleration.

Jaguar, on the other hand, are in the business of building luxury cars. Their motivation to supercharge their small-displacement 4.0L V8 was torque, not horsepower. Jaguar's AJ-V8 is a fine engine, but due to its fuel-sipping design, lacking somewhat in the low-end grunt department. As in, when merging onto freeways with a short entrance ramp. Or, on the interstates, dealing with the miles-long grades in the Rockies,

With its blower, the JXR version of the X-308 enables its driver, without having to engage Sport mode, to simply dip the throttle into that vast wellspring of torque and power through driving challenges. It’s a maxim that a luxury car have sufficient power on tap to deal with most situations. And Jaguar followed through with the XJR and Vanden Plas Supercharged.

But those blown Jag sedans were NOT designed for drag racing. For one thing, their rear differential will break if subjected to drag-race starts. It’s the same diff as used by the naturally aspirated engines, and cannot withstand the abuse.

Add to this the 4.0L version of Jag's wonderful all-British V8 just plain lacks the cubic inches required to bring a big sedan up to speed at rates reserved for today's ultra-expensive German performance sedans. I read three car mags monthly, and have noticed our blown X-308s barely make it to the bottom rung of today's performance cars in terms of acceleration, even when they are pretty cheap compact performance cars.

And while our Jags' Bilstein shocks and fancy suspensions keep our big sedans well under pilot's command in the big sweepers, it would be wise to avoid pink-slip showdowns with M5s or AMG 6.3s. Or Audi S7s for that matter. Those models were designed to produce near-supercar performance numbers, whether on the straights or in the twisters, at the cost of a six-figure price tag, a buckboard ride, and a noisy exhaust. Our cars had a completely different, and I suggest more practical mission statement, and continue to pull it off wonderfully in the real world,

When we get back to the real world of today's non-motoheads, you know what? Most passengers in luxury sedans expect to be cosseted, not scared cross-eyed by violent acceleration and at-the-limit cornering.

A couple of weeks ago I took a friend who is not a motorhead, and in fact owns a new Mercedes C-Class sports coupe, out for a dinner engagement in my 2001 XJR. It was his first time in a British saloon car. Upon entering the car I noticed he was coming to terms with the very un-German notion of luxury for its own sake.

As I am prone to do now that I’m in my 60s, I drove chauffeur style, easy on the gas and brakes, no side forces in the corners. This relaxed my companion, and he made mention of my car's sybaritic interior, resplendent in hardwood and Connolly leather the like of which no Merc sedan has ever known, not even the legendary S600.

At one point, pulling away from a stoplight and onto a freeway on-ramp, I put my foot in it enough to get us moving but not enough to trigger a downshift. That flat torque curve just hauled us smoothly up to freeway speeds, with zero drama, Involuntarily, my companion said, “Wow.”

And that, my friends, is how a luxury sedan delivers power. Its mission is to reassure both driver and passengers that whatever on-the-road challenges come up, it is on top of — all the while delivering a traveling environment remeniscient of an Edwardian gentleman's club.

To reduce this car's mission statement to lowest-possible quarter-mile times dishonours both the marque and the committed gearheads who live by the quarter mile. Both have a purity of vision but it is not the same vision!

You don’t go shooting geese with a Hawken rifle. It would be equally unwise to challenge a recent 8-cylinder Mustang while driving an infinitely more sophisticated European luxury saloon. Just give them their due and rise above it, And take comfort that you are in possession of the high point of luxury point-to-point transportation.

The new XJ series, with its huge wheels and ultra low profile tires, just rides like a buckboard. And the new S-class might be brilliant but it is too far outside an American owner's learning curve to take advantage of the amazing tech.

Out of all the choices we've we’ve had over the years, and having driven most of them, I can only conclude that we X-308 owners have enjoyed the optimal luxury car of the modern age. If this is my last car I will not feel denied,

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