Jaguar is introducing a new generation of its award-winning AJ-V8 for 2010, and the first to benefit from this larger and more potent engine are the XFR Sedan and the XKR Coupe/Convertible. If that's not enough, both of these cool cats also gain a host of other functional upgrades; and in the case of XKR, receive some significant restyling, as well. Although neither is due in dealers until summer, we recently put both through a brief spring fling and came away seriously impressed with the effects of the transformation.
All versions of the lighter, more compact Gen III AJ-V8 see displacement rise from 4.2 to 5.0 liters, move from port-type to direct fuel injection, adopt a new, more efficient type of variable cam timing and feature dual-stage intake runners. In top-line "R" form, the naturally aspirated 385-horsepower version that will be used in the standard XK and XF Premium models gives way to an even more exhilarating force-fed variation endowed with 510 ponies -- 90 more than its 2009 counterpart. Fitted with a state-of-the-art Eaton twin-vortex supercharger, this still-silky-smooth all-aluminum V8 makes an equally stout 461 pound-feet of torque -- a bump of 12 percent -- that peaks at just 2,500 rpm and continues on flat to 5,500 revs. Backed by an electronically controlled six-speed automatic with paddle shifters, it delivers instant and seemingly effortless response, sending the 3,968-lb. XKR from 0-60 mph in a claimed 4.6 seconds and blasting the 4,169-lb. XFR to that benchmark in just 4.7 ticks. Despite that added muscle, the blown Gen III engine still maintains the same fuel economy as its 4.2-liter predecessor. True greenies may not be impressed with the XKR's 15/22 mpg EPA numbers and the XFR's 15/23 mpg stats, but Jag say they're the only cars in the over-500-horse category not subject to any gas guzzler tax.
To put this underhood might to best use, both of these Fast Cats also boast Adaptive Dynamics and Active Differential Control for 2010. Capable of sampling individual shock absorber rates 500 times per second, the former can seamlessly stiffen/soften chassis settings as needed to decisively curtail body roll during severe cornering and transition moves. The latter component transfers up to 90 percent of the available engine power to the outside rear tire under similar high-load conditions. Collectively, they give both vehicles a remarkable combination of handling precision and ride compliance. Our only gripe is that the Multi-stage Stability Control can become a bit overactive on grittier surfaces, although bolder pilots have the option to switch it off completely. No complaints about stopping power, which comes from massive anti-lock disc binders that match up nicely with sticky performance tires wrapped around 20-inch alloy wheels that are standard on both cars.
While hard-core excitement is the undeniable heart of the XFR and XKR, there's plenty of soft-centered soul inside of their well-isolated cabins. Both interiors display loads of contemporary Jaguar flair, with polished wood and textured metal setting off supple leather upholstery, highly supportive, multi-adjustable bucket seats and a full array of standard power assists in addition to their "R" specific trim and instrumentation. As with exterior revisions, the biggest visual changes for 2010 are found in the XKR, which gains the same Drive Selector Control for its shift-by-wire six-speed automatic transmission that was introduced in the XF/XFR.
Playing in the den of these R-type Jaguars does ratchet the price of entry up significantly beyond their less-intensive kin. Where the base 2010 XF (which still retains the Gen II 4.2-liter engine) opens at $52,000 and the XF Premium starts at $57,000 the XFR is set to command $80,000. On the XK side of the ledger, the naturally aspirated Coupe and Convertible start at $$83,000 and $89,000, respectively, while their XKR counterparts will be priced at $96,000 in Coupe form and $102,000 as a Convertible.