Purchased the car in 2013. My version is the "facelift model' and comes with the 6.0 litre V12, which provides solid performance throughout the entire RPM range. I also own a 1985 5.3 litre V12, and the engines are quite different in their approach. Whereas the 6.0 has more grunt and torque, it's not as smooth as the 5.3. Both engines are much more 'alive' during highway driving, and are a pleasure to 'open up' when there is an empty stretch of road ahead of you, with the 6.0 litre's real world top speed being slightly in excess of 160 MPH (260 km/h).
The XJS is a heavy car, and should viewed as a Grand Tourer as opposed to a hard charging sports car. The XJS can be driven for long periods of time and you will not be tired of hearing the drone of a high revving engine, or sore from a harsh suspension setup.
The seats are soft and comfortable, and the suspension is set up to somehow provide an extremely comfortable ride, but still handle extremely well in the curves for such a large car.
The ergonomics are a little different in this car, but nothing you can't get use to.
The cruise control button is where most people would naturally reach for the power window button. The steering wheel only has tilt, and it can take a bit of time to find a comfortable position, as the seats do not go as far back as they do in newer cars. However if the position of the tilted steering wheel is slightly too high, and you go into a turn palming the steering wheel, your fingers will actually hit the front windshield.
The car is quite large, but somehow Jaguar made the interior very small. So small in fact, that the rear seats touch the front seats, leaving no room for passengers when I'm in my comfortable driving position (I'm 6ft tall). However, if there are just two of you in the car, the acres of wood, the plush leather seating, the super smooth suspension and never ending power more than make up for these small ergonomic hiccups.
Please do not buy these cars unless you are willing to pay the associated costs of driving such an awesome machine. You cannot maintain a European V12 luxury GT car such as the XJS, on the budget of a 4, 6 or even 8 cylinder domestic car. This is the reason you see many Jags that are in poor shape, or deemed nightmares to own, as the purchaser goes in uneducated about the real cost of ownership, and is just happy to get the car at a relatively low initial purchase price.
The V12's are thirsty machines that require premium fuel. There are no two ways around it. Some people say they can get away with putting in less than premium, however this is not what the manual calls for, and should not be expected. A pinging V12 engine that gets destroyed because of an improper octane rating can cost between 15000-17000 to be properly rebuilt and installed.
The engine oil capacity is about 11-12 quarts, and if you plan on using synthetic oil, plan on one expensive oil change.
Spark plug changes are a challenge, and if you do not have a special tool, you may have to remove the cruise control bellows and A/C compressor to get 2 of the 12 plugs out. Also, 12 plugs and 12 wires etc., cost a lot more than they do for a 4, 6 or even 8 cylinder car.
Should the A/C evaporator conk out, look at 15-20 hours of labour time to replace it, as the whole dash has to come out.
These cars should be garaged, and in my opinion, undercoated and driven only in the summer, as they can suffer from rust if not very well looked after.
By now, I'm sure you understand why some people say the cars are junk or are nightmares to own, as they are complex machines that may require a small (relatively speaking) initial purchase price, but require extra upkeep, and then can cost quite a bit more than what the average motorist may be used to.
For many people, these costs are unacceptable when they plan on maintenance bills more closely associated with a 4 cylinder domestic car, than a 12 cylinder European import. If you can turn your own wrench most of the time, and find a dedicated Jaguar specialist with reasonable rates, the upkeep is not that bad when you consider the car you are getting, and that the engine can easily last 300000 miles (not a typo).
There are 4.0 litre / 6 cylinder versions of this car with similar performance and cheaper overall maintenance costs, and whichever one you choose will be down to personal tastes after test driving both.
With either car, you are getting nothing but class. Everywhere you go, people will stop to talk to you about the car, and admire it. You will be hard pressed to find a V12 with this combination of class, good looks, power and comfort with a (RELATIVE to other V12 cars) low cost of ownership.
Just know what you're getting into before buying, and you will enjoy the sound only a V12 engine can provide, while cruising in complete comfort with the top down!