When it comes to large luxury sedans in the U.S., six-cylinder engines are rarely on the options list. BMW quietly introduced a six-cylinder 7 Series last year, while Audi did the same with its A8 just this year.
Jaguar isn't being so coy about it. The new XJ 3.0-liter is an integral part of the company's engine development strategy. The new supercharged V6 will also go into the XF midsize sedan and the highly anticipated F-Type sports car due out next year. It's not overreaching to say that this new V6 will become the bedrock on which the Jaguar range is founded for years to come.
In the case of the 2013 Jaguar XJ, the new engine is part of a raft of subtle change for the 2013 model year that includes revised suspension settings and upgraded infotainment systems. In combination with the introduction of a new all-wheel-drive version, Jaguar is hoping to get the XJ onto shopping lists that may not have even considered the brand an option before.
A New but Familiar Engine
The new V6 is effectively a cut-down version of Jaguar's familiar 5.0-liter V8. The loss of two cylinders has been accompanied by a reduction in capacity from 5,000cc to 2,995cc. To compensate for its reduced displacement, a twin-vortex Roots-type supercharger has been mounted in the "V" of the engine that features an electronically managed boost control, which Jaguar claims increases the operating efficiency by up to 20 percent.
The engine is further enhanced with dual independent variable cam timing (DIVCT) and spray-guided direct injection (SGDI). Together with front and rear balancer weights, Jaguar's engineers aimed to ensure that the V6 matches the refinement of the V8.
In performance terms, the supercharged V6 still gives something away to the free-breathing V8. Despite having the highest specific output (125 horsepower per liter) of any of Jaguar's engines, its peak power of 335 hp at 6,500 rpm is still 45 hp down on the V8. The V6's peak torque of 332 pound-feet is available at 1,750 rpm, but comes up 48 lb-ft down compared to the V8.
Power Where You Need It Most
These figures, though, tell only half the story. The introduction of an eight-speed ZF automatic (now common to all XJs) has made the performance more accessible, while also increasing the fuel efficiency. Eighth gear is so tall that at the legal limit, the engine's barely ticking over. Its EPA ratings have climbed to 18 city/28 highway mpg, which is pretty respectable for such a large sedan.
On paper, the 0-60-mph sprint time increases from 5.4 to 5.7 seconds from V8 to V6, but in the real world, you'd be hard-pressed to tell the difference between the two. The throttle response is good, if not quite as rabid as the V8's, and there's plentiful torque available throughout the rev range.
It sounds good, too. Almost inaudible at a standstill, its smooth timbre rises through a gentle crescendo until the upshift at around 6,500 rpm. It's just loud enough to justify the XJ's "sport sedan" aspirations without compromising its luxury pretensions. No doubt the exhaust in particular will enjoy a major retune before this engine debuts in the even sportier F-Type.
A More Refined Ride
When the XJ was originally launched, there was some criticism of its low-speed ride quality. In our original test we wrote, "It's a surprise to discover that this XJ does not soak up low-speed city bumps with quite the velvet pliancy of its ancestors, many of which were exceptional." We were not alone in our verdict and Jaguar has responded by retuning the spring and electronic damper rates across the range. Not surprisingly, it's claiming an improvement in the ride quality without compromising the XJ's handling.
The engineers softened the setup of the standard mode, while retaining the firmer damper settings for the driver-selectable Dynamic mode. On our U.K. test route around Shakespeare's Stratford-upon-Avon, there was evidence of a modest improvement in the low-speed ride, but it would be wrong to suggest the XJ now rides with the cushioned aplomb of a Mercedes S-Class.
Journey out on to the country lanes, though, and the big Jag displays an agility that even the Merc can't match. Switch to Dynamic mode, shift using the steering-wheel-mounted paddles and the 2013 Jaguar XJ does a decent impression of a sport sedan. Indeed, the V6 does such a good job that we'd question whether it's really necessary to pay an extra $8,000 for the V8. This is a nicely balanced, usable car, not an underpowered entry-level model.
The rest of the XJ's changes reflect little more than the car's natural evolution over time. There are upgrades to the satellite navigation system to offer additional points of interest and it's now happy to guide you in Arabic, should you so desire.
There's also a change in the brand responsible for the top-end audio systems. Having made such a song and dance about Bowers and Wilkins, Jaguar has changed supplier. The top-of-the-range, 825-watt, 20-speaker system is now the work of Meridian. It sounds terrific, although we'd never really questioned the quality of the old B&W system.
Is This the Future?
The 2013 Jaguar XJ is not going to overtake the Mercedes S-Class as the default luxury sedan for the ambitious executive. Jaguar isn't ready to play that game just yet. At this point, the company is merely trying to insert the XJ into all the proper segments.
The addition of the less expensive and more efficient XJ 3.0 is one step in that direction. Adding optional all-wheel drive is another. The rest of the work is left to the performance and aesthetic appeal of the XJ, and it delivers readily on both counts.
The modest deficit in performance relative to the V8 is offset in our eyes by the efficiency gains. And given that even the most powerful of sedans in this class are too big to be considered truly sporty, the drawbacks to V6 power come down to prestige more than anything else. If you can get beyond that, the 2013 Jaguar XJ V6 is every bit the luxury sedan that Jaguar promises.
Edmunds attended a manufacturer-sponsored event, to which selected members of the press were invited, to facilitate this report.
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