Back in the late Eighties, I was sitting outside a pub in Fulham with my old writing and business partner when someone pulled out of a side turning in a Toyota Supra and accelerated smartly down the road. As the car shifted lumpily into second gear, I remember, even today, that we each looked at the other in an eye-rolling way and said: “What a prat.” He’d bought a sports car and then specified it with an automatic gearbox. Which meant he hadn’t bought a sports car at all.

When I was a young man, I reserved a special kind of hatred for automatic gearboxes. They made all cars, no matter what they were, into convenience tools. Take away the pleasure of a well-executed downshift and you were taking away everything that mattered to the true petrolhead. Auto cars, even the Ferrari 400, were the automotive equivalent of fast food. Convenient, for sure, but no burger, no matter how easy it is to eat in the street, can possibly be a match for a blood-red fillet steak.

Things, however, have changed. There are all sorts of moments in a man’s life when he can truly say he has become “old”. The moment his first child is born. The moment he buys his first pair of slippers. The moment he starts to think the world is getting worse. But, actually, the real moment is when you say to a car salesman: “Can I have it with an automatic gearbox?”

Graham Norton summed it all up the other day when he appeared on a television programme. He said that changing gear in a car is like having a remote-controlled television and getting up to change the channel yourself. It’s stupid. And, of course, he’s right.

I like to kid myself these days that I prefer an auto because I’m busy and having something change gear on my behalf allows me to do other things while driving. Speaking on the telephone, for instance, is almost impossible if you have to steer and shift cogs as well, especially now you need to keep at least one eye out for the Stasi. But the main reason is that I simply can’t be bothered to do it myself.

So what about flappy paddles, which give you the manual gearbox without the tiresome need to press a clutch pedal down or move a stick? Well, yes, they can change gear very quickly, but speed is not the issue — off a race track, why would you ever want to go from third to fourth in 60 milliseconds? It’s the “feel” you want from a gearbox, the sense that you are controlling the machine.

And with a flappy paddle box, that control is gone. Try to change down when the resultant revs would be too high and the system simply won’t allow it. Forget to change up and when you hit the red line, the silicon nanny will step in and do it for you. It’s like having a driving instructor along for the ride, with dual controls. It is terrible. The most pointless invention since procon-ten.

I have a similar problem with diesel engines. Time was when I hated them. I said diesel was the fuel of Satan and that anyone who chose a car with no spark plugs had in effect given up on life. Choosing such a thing would be like choosing a pair of trousers with an elasticated waist simply because they were easy to clean.

Now, though, I simply cannot understand why anyone would buy an ordinary car with anything but a diesel engine. Of course, those with petrol flowing through the injectors can rev so much more freely, but when was the last time — honestly — you went anywhere near the red line?

The trouble is that second gear in a lot of cars these days can take you to beyond the motorway speed limit. So in a run-of-the-mill saloon, you simply don’t need the engine, ever, to spin up to six, seven or even eight thousand revs per minute. You may as well, therefore, have a diesel, which is all out of ideas at 4500rpm.

I can’t believe I’m saying any of this. I remember the launch of the first diesel automatic car — a Citroën BX, if you could care less — and I remember thinking that life couldn’t possibly get worse. Canal-boat noises. No go. No need to change gear. It was, I reckoned, the end of days.

Of course, it’s not just me that’s changed in the intervening period. Diesel engines have too. Time was when they rattled the windows in your house, gave your children cancer, made the Houses of Parliament black and had all the power of Belgium.

Today, with the notable exception of the diesel in a Volvo XC90, which is laughably awful, they are completely different. BMW’s diesels may not be the most economical but they are unbelievably quiet and possessed of so much power, you would swear to God they were running on lightning bolts.

And they pale into insignificance alongside the diesels now being made by Land Rover and Jaguar. The diesel in my Range Rover is unbelievably good. You’d have to be clinically insane to choose the 5-litre V8 instead. And now there’s a new 3-litre twin-turbo V6 diesel that you can specify for your XF.

Let me put the figures on it for you. In the top-spec S model I tried, you get 275 horsepowers and an astonishing 442 torques, which means you can get from 0 to 60 in around 6sec and onwards to a top speed of 155.

These are the figures you might expect from a petrol car. But now look at the ones you wouldn’t — a mere 179 carbon dioxides and the promise of 40 or so mpg. It really is a case of: here’s your cake. Now tuck in.

But the best thing about Jag’s engine is the silence. It is astonishingly quiet, even when you start it up first thing in the morning. There are no vibrations either, which means it feels exactly like it’s running on petrol. Except for when you put your foot down and that second turbo unleashes the monstrous torque. Then it feels like it’s running on a gallon of bloody mary.

There is just one tiny problem, and, weirdly, it affects the Range Rover diesel too. When you pull away from a standstill, it feels like the throttle cable has snapped. So you give the pedal a hefty shove, which means that you lunge onto the roundabout at the precise moment you decide the gap’s not big enough. Apparently, this is a software problem that can be cured. I wish it would be.

I also wish the ride were better. I think the low-profile tyres are to blame, but, whatever it is, the car pitter-patters at low speeds and such a feel is completely at odds with the torquey diesel engine, the automatic gearbox and the sense that Jags aren’t supposed to be this way.

I must also criticise the seats. There is so little side support that in every corner you end up on your passenger, which is fine if your passenger is Lily Allen. But I ended up on James May, and that was horrid. For me.

That, however, is it. A hesitancy to the throttle, a seating problem that’s an issue only if you drive fast and a small but important ride flaw that could almost certainly be solved with smaller wheels and taller tyres.

The rest of the car is brilliant. I wasn’t sold on the XF when it came out. It simply didn’t look as sharp as the concept we’d been shown earlier. But with memories of that concept fading, we are left with a genuine looker that manages to be practical and spacious as well. Plus, you can get one of these cars, albeit not the variant I drove, for £2,500 less than the cheapest BMW 535d.

I apologise for the rather boring, dry review this morning but, having taken this diesel car with an automatic gearbox to a friend’s 50th birthday party last weekend, it’s how I feel. Boring, dry and possibly in need of some slippers.

The Clarksometer

Jaguar XF 3.0 Diesel S Portfolio

Engine 2993cc, V6

Power 275bhp @ 4000rpm

Torque 442 lb ft @ 2000rpm

Transmission Six-speed auto

Fuel 42mpg (combined)

CO2 179g/km

Acceleration 0-60mph: 5.9sec

Top speed 155mph

Price £44,200

Road tax band I (£175 a year)

Clarkson's verdict

Either I’m getting old or this car’s brilliant

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