Unlikely partnerships are often fired in the heat of necessity or adversity. With sales of Jaguar's X-type not hitting the heights the company needs, the firm has thrown out its old rulebook about engines which said in big bold letters: 'It must be petrol and V configuration'.
For now we have diesel and four cylinders. Jaguar has never been a brand associated with diesel until now, but bucketloads of pragmatism have been shovelled into this venture, because for Jaguar to flourish as a thoroughly modern car manufacturer it has to have a thoroughly modern line-up of vehicles, and you aren't anywhere these days without a diesel.
That's because the market for diesels continues to soar, especially in the UK fleet sector that is the X-type's key battleground. Jaguar sold 19,000 X-types in the UK last year, with about 70% of them going to fleets. Although the diesel offering is only one model, the 2.0D is expected to account for up to half of all X-types sold.
The diesel will also help the X-type in the major European markets because at the moment, it barely registers. Last year 13,000 X-types were sold throughout Europe, which in volume terms is miniscule.
But with markets such as France, Austria and Belgium experiencing 75% diesel penetration in the premium sector, it didn't really have much of a chance. The 2.0D should help to change that.
Officials are cagey about figures, and not surprisingly: a four cylinder diesel in a Jaguar makes sense from rational and fiscal sense, but will it appeal to the average punter who likes their Jaguars burning petrol in at least six cylinders? And how much could it grow X-type sales by?
With diesel penetration in the market growing all the time, any projected figure for this car is difficult to call. There are just too many variables.
The problem Jaguar will have is it needs to sell this car to conquest customers. Just persuading potential X-type buyers to go for this over the petrol version does not really help much. It needs to be biting chunks from Audi, BMW, Mercedes-Benz, Ford, Vauxhall and all the other major players.
Jaguar engineers have worked very hard to ensure no damage to the brand is done through the introduction of a diesel engine. A chuggy, noisy diesel motor would lead to accusations that they had just bolted any old engine in the front and had gone chasing filthy lucre while ignoring a heritage of smooth, whispery motoring.
So they have taken the common rail TDCi unit found it the Ford Mondeo and reworked it. The focus has been on reducing noise at idle, improving cruising refinement and getting a good spread of mid-range acceleration. This has been done through a lot of effort in packaging, vibration control and engine management.
The 128bhp 2.0D has a new cylinder head, new 'short nozzle' fuel injectors which reduce noise and a development called the Combustion Noise Sensor (CNS), which listens to each stroke in each cylinder and adjusts the injectors to ensure the quietest possible running.
This is done by calculating the minimum drive needed to keep the engine going at its current output, and apparently the system learns over time the characteristics of the injectors and improves. As a result Jaguar reckons the car will be at its noisiest for the first 500 miles while the CNS is getting on first name terms with its engine, and will get progressively quieter after that.
Installation is key to the 2.0D and Jaguar has added extra foam insulation and a larger hood lining above the engine. The lining between engine and dash is also considerably denser than on the petrol cars, while a new undertray has been added.
Dampers, springs, roll bars and mountings have all had to be revised due to the different, more torquey characteristics of the diesel motor.
The 2.0D is not yet Euro IV emissions compliant, which would have really put the wind up the competitors, but according to the engineers to hit that level at this moment would have meant that refinement and fuel economy were compromised, and they were not willing to take that risk with this car.
Having a smooth engine really is the essential part of Jaguar's first foray into diesel. So for now the 2.0D is Euro III, but drivers wanting a low level of company car tax should not be unduly worried, because it has the lowest carbon dioxide emissions in its class, allied to one of the lowest prices.
The 2.0D matches the petrol model, starting at £19,995 on-the-road with the Sport costing £22,350 and the SE £22,995.
This makes the 2.0D very good value, especially allied to the 18% benefit-in-kind tax band it will fall into for the next couple of years. Combined fuel economy is rated at a very useful 50.3mpg.
Compare that to a BMW 320d, which has the current best diesel engine in terms of driveability. That starts at £21,650 on-the-road and with a CO2 emissions level of 153g/km and fuel economy of 49.6mpg.
Residual values are yet to be set, but experts at CAP envisage a stronger residual value than the 2.0 petrol, which currently stands at a very solid 41%. So the X-type 2.0D stacks up very well in terms of figures, but what about out on the road?
Behind the wheel
It was very hot when I first got into the 2.0D and the climate control was trying to blow my socks off to keep the temperature down. Turning the key to fire the engine into life, I had to switch the air con off because I couldn't hear the engine. It was either a good introduction to the car, or it hadn't fired up.
In fact it had, and at idle it has to be said the X-type 2.0D is almost reverentially quiet, and appreciably more so than the Mondeo TDCi, which says a lot for what the engineers have done. While it may be the first Jag in aeons to have a four-cylinder motor, extensive work has been carried out on the TDCi unit and you would be hard-pressed to notice any similarities. Get on the move and a number of things become immediately apparent. There is no low-down burst of torque – indeed nothing much happens at all below 1,800 rpm, which can be frustrating.
Where the unit in the Mondeo is louder, more boisterous and the torque feels as though it comes in with much more of a surge, in the Jaguar almost the exact opposite is true, despite the fact the torque and brake horsepower figures are exactly the same and performance timings are very close.
The Jag does 0-62mph in 9.5 seconds, the Mondeo 0.3 seconds slower. Engineers at Coventry have turned an excellent but lairy engine into one with much better manners.
There is no heaving bow-wave of torque for 1,000rpm or so like many diesels, and although peak torque of 243lb-ft is available at 1,800rpm, the engine provides decent, steady linear pull up to 3,500 rpm. However, as with the Mondeo TDCi, an overboost facility is available for mid-range acceleration. This system orders the turbo to spin a little more quickly, releasing extra torque from the engine, up to 258lb-ft.
But the 2.0D does not feel particularly fast because everything happens so smoothly, although it has to be said some of the pre-production cars at launch were suffering from flat spots during heavy acceleration. However, I would be surprised if those little niggles were still there when the cars reach UK showrooms in September.
Under acceleration, the 2.0D makes a unusually attractive noise for a diesel and will hustle along in third or fourth gear on A roads, although in fifth it is surprisingly short geared, which could have an impact on fuel economy for long motorway trips. In handling terms, the revisions to the suspension set-up have not changed the ride or driving characteristics: they are still OK, although nothing to write home about.
An area in which the 2.0D's powertrain is excellent is on downshifts. Because of the high compression rates in a diesel engine, shifting from fourth to third, or from third to second, can often result in a lot of drivetrain shunt and an excessive amount of engine braking, which doesn't help comfort. There is very little of this in the 2.0D and it downshifts more like a petrol-powered car. According to the engineers, they have spent a lot of time making the transition between gears as smooth as possible and it seems to have worked.
The car will only come with the five-speed manual 'box to start with, which is odd as the Mondeo now has a six-speed unit, while an automatic may or may not follow. Jaguar officials are keen to stress they want to get this particular car absolutely right first before they start expanding the line-up.
WHAT you have here is a diesel car with an engine that is quiet at idle, sounds pretty good when under load, has smooth downshifts and a nice wide, progressive torque spread. Sounds like a petrol engine to me. Jaguar's first effort at a diesel should be a success.
Model: Jaguar X-type diesel
Engine (cc): 1,998
Max power (bhp/rpm): 128/3,800
Max torque (lb-ft/rpm): 243/1,800
Max speed (mph): 125
0-62mph (sec): 9.5
Comb fuel consumption (mpg): 50.3
CO2 emissions (g/km): 149
Transmission: 5-sp man
Fuel tank capacity (l/gal): 13.5/61.5
Service interval (miles): 12,500
On sale: September
Prices (OTR): 2.0D £19,995, 2.0D Sport £22,350, 2.0D SE £22,995