When you book a rental car, even if you select something that is “model guaranteed”, you really can’t be sure in advance what you will actually receive. But when the car I am testing is sourced from the dealer, as a service loaner, then at least the marque is pretty much a certainty, certainly when the dealer in question only sells one brand, though the model you will received may be almost anything from within the range, depending on what was to hand to populate the loan car pool. And so with my much loved Audi S4 hitting the 60,000 mile mark and a service being called for, I was curious as to what was going to be allocated this time. The answer turned out to be close to the car I drive on a regular basis, but from somewhat lower down the range, an A4 2.0 TDi S-Line. This is the first example of the B7 generation of A4 saloon that I have sampled in A4 guise, though previous loaners have included the Avant version in both B7 and B6 generations. Like most manufacturers these days, Audi have a program of almost continuous improvement, so I was interested to see what the latest version was like, and noting from the paperwork that the approximate retail value of this car was stated as £24k, whereas mine is around £38k, to get an answer as to what you sacrifice by choosing a car at two thirds the price. I had a day to find out, and a trip along the M4 to a meeting in our Bedfont offices, so there was not going to be much opportunity to do more than a long motorway journey, with a few miles on B roads in quest of photo locations for the pictures that accompany this report.

A lot of the money that makes up that £14k of price difference concerns the engine and transmission and all the other mechanical upgrades that go to make a 343 bhp all-wheel drive saloon out of what is more commonly sold as a regular mid-sized premium saloon and estate. The paperwork said 2.0TDi but even if it had not, I would have been in no doubt as to which fuel type was involved when I started it up, as the tell-tale diesel sounds are still very evident especially when the engine is cold. Fortunately, they quickly abate and most of the time, this comes across as a refined and quiet powerplant, definitely among the best you will find in class. Audi offer the 2.0 TDi unit in the A4 with a choice of power outputs and there is no badging on the car tell you which one you have, though careful inspection did elicit a 125CV figure, which in more familiar terms means 170 bhp, meaning this is the more powerful of the four cylinder diesel units currently offered. The last A4 I had driven in Avant form, had been a 140 bhp car, so I rather expected to feel the difference, but even allowing for the fact that this had been some 9 months back, it was hard to be sure that there was that much urge available. To get the most out of the car, you will need to use the gears a lot. And just as Audi has been steadily improving the refinement of their diesel engines since the emergence of the 2.0 TDi unit which gradually replaced the earlier 1.9 litre unit, so the gearchanges have also got better, with this one feeling very slick and slotting through the gears with none of the baulkiness that used to be evident. First gear is only really useful for moving off, but the next four gears are well spaced and once you get to the rev range where there is most torque, there is strong acceleration, just when you need it. Sixth gear is definitely chosen to permit relaxed motorway cruising, and there is not much acceleration here. I found the need to change down at least one gear, and sometimes two if I lost speed in traffic on the motorway and then wanted a bust of acceleration but this was no hardship given the excellence of the gearchange.

The steering definitely felt lighter and less precise in my car, and indeed this is one facet of the A4 that tends to generate unfavourable comparison with some of its rivals. Although the quattro all-wheel drive system is available with this engine, it was not fitted to my test car which was a front wheel drive model. There’s a lot less weight with a two litre engine as opposed to a 4.2 litre engine up front and the latest gearbox type has allowed the engine to mounted a little further back in the chassis than was the case before with the result is that this A4 handles tidily with good levels of grip and no unpleasant or unpredictable surprise on the B roads. Taken to extreme, I understand that the car will understeer, but you probably won’t be aware of this whilst driving on public roads. I certainly was not. I am used to a very firm ride in the S4, so it was good to see that this is softened a bit in the A4 even when fitted with the S-Line suspension. In general, the car was comfortable on most road surfaces, absorbing the bumps and surface changes very well. Not surprisingly, the brakes are less powerful than in the S4, and I thought that rather more effort was required before anything much seemed to happen when pushing on the pedal. There is a conventional pull-up handbrake fitted between the seats. As the body of this car is identical to that of my S4, even down to the shape and size of the mirrors, then so visibility is as I am used to, and that means generally good, with just a small blind spot of cars alongside you. Judging the back of the car is not that hard and the tail is relatively short, so the car is easy to park up.

The inside of this car was very similar to my S4, too, but there were detailed differences. Whereas mine sports a carbon fibre inlay around the gearlever area and across the dash and on the door casings, this one had a silvery metal effect inlay which was not particularly to my taste. That aside the main dash moulding is identical and you get the same superlative level of quality that really is second to none certainly at this price point and indeed worth of cars costing a lot more. It is all easy to use, too. There is a single cowl covering the instrument cluster which comprises two large dials for speedo and rev counter with smaller gauges for fuel level and water temperature in the lower outer edge of the cluster. All are clearly marked and easy to read. There is a digital trip computer display area between the large dials, and you can cycle through the different data points by pressing a button on the end of the wiper stalk. Twin column stalks operate indicators and wipers and there is a quality feel to these as indeed there is to every button or switch that use. Lights operate from a rotary dial on the dash to the right of the wheel. Small buttons and thumb wheels on the steering wheel spokes are used for audio repeater functions. The central part of the dash on this car was slightly different compared to mine. It featured an upgraded Audi Concert audio unit which is taller than the one in my car, so the whole climate control panel is mounted down that bit lower so it is flush with the central tunnel, thus depriving you of a small stowage area. The audio unit itself was easy to use and the sound quality was good. I had no particular need to test out the automated climate control as the test was on a nice moderately warm day.

S-Line trim brings with it sports seats, though these are different to the ones in the S4. They were covered in a sort of cloth which made me glad of the fact that I had upgraded the covering sin my car to leather. The seats are manually adjustable with a bar under the seat and levers on the seat sides, with a handy height adjuster as well as backrest rake and lumbar support. The steering wheel telescopes in/out as well as up/down. After having driven the English length of the M4 and back in the day, I can attest to the comfort of the seats. Room in the back will generally be adequate, there being more space here than there was in the previous bodyshell, as cars in this class strive to find that bit more space, though with the front seats set well back, some will still find it a bit tight. The back of the front seats is shaped with slight cut-outs to either side of their centre which will help a bit, too, though it does mean that there is no stowage net on them. There is a central tunnel but more of an issue for a middle seat occupant is the fact that the centre console unit comes a long way rearwards and may get in the way of the someone sitting here. Headroom should not be an issue for anyone apart from the exceedingly tall. The boot is a nice regular shape, and the opening comes down nice and low so there is not much of a lip. There are useful stowage wells at either side of the main boot area and there is some useful space for odds and ends under the floor around the spare wheel. The rear seat backs can be dropped down to create a longer load platform. Inside the cabin there is a good-sized glovebox, bins on the doors and a cubby under the central armrest.

Audi offer the A4 in what seems like a bewilderingly complex model range, but if you really look at it, things can be simplified somewhat. First you choose the body type: four door saloon, five door Avant, or the stylish Quattro. And then you choose the trim, of which the key three are Standard, SE and S-Line. And then select the engine and gearbox, and that is where the list of choices gets big, with a mix of four and six cylinder petrols and diesels – no fewer than 14 have been offered since the launch of the B7 generation – and 5 or 6 speed manual and 6 or 7 speed CVT automatics. And then you can have quattro all-wheel drive with some of the engine combinations. After all that, there are pages and pages of options to select from if you really want to personalise the car. The Standard trim level is a bit basic, though you do get alloy wheels and climate control, front fog lights, an adjustable steering column and a full complement of driver, passenger and side air bags as well as an alarm but not a lot else in the way of features. SE trim adds heated mirrors, a height adjustable driver’s seat. rear electric windows and cruise control. S-Line trim brings with it distinctive 17″ alloy wheels, lowered and firmer suspension, S-Line badging inside and out and sports seats. There was a short-lived S-Line Special Equipment model offered in 2006 which added further features including leather seats, and an audio remote.

Be in no doubt, the A4 2.0 TDi is a good car. It drives well and it is impeccably finished. It is easy to see why the car is popular and to believe that anyone choosing one would be pleased with their purchase. It might only cost 2/3rd of an S4 but in many ways you are getting a lot of the good bits for a lot less money. Test, development and production of the S4 uniques is costly! But before concluding with that thought, another one crossed my mind. Not many weeks prior to this test, I drove a Ford Mondeo ST TDCi, and was blown away with its excellence. Whereas the regular 2.0 litre TDCi Mondeo is lumbered with a rather below par engine, the 2.2 litre unit in the ST TDCi is another league altogether. And this car retails for £2k less than the Audi, and will likely depreciate faster, so the price gap will widen as the car ages. Is the Audi worth the extra? In many ways, the honest answer is probably that it is not, but in the world of badge snobbery that we live in, the fact is that the Mondeo has a Ford badge on it whereas the A4 is still seen as a more aspirational product. And its maker knows that people will pay extra for that. Be in no doubt, it is a good car, but the point is that there are others that are just as good these days.