Jaguar finally broke with tradition with the X-type in the summer, and Honda has now done so with the Accord. True, it borrowed a Rover unit for three years with the old Accord and had an Isuzu-sourced diesel in the Civic, but they were and are more of a toe in the water exercise. This time Honda has done a full swallow dive, with pike.
But it didn't really want to. Head of the programme, Kenichi Nagahiro, admitted as much at the launch. This is the man who came up with the idea, and then built, Honda's legendary VTEC engine. The firm recognised the importance of a diesel engine to achieve profitability in Europe and so put the top man on it.
The criteria for the engine was for it to match Honda's petrol engines as closely as possible in the way it delivers its power, the shape of its torque curve and its levels of refinement. It also needed to be Euro IV-compliant, be extremely smooth and have very low emissions.
Those emissions are going to be about 143g/km of CO2 at launch for the 2.2-litre diesel in the saloon, with a combined fuel economy figure of 52.3mpg. The Tourer comes in at 153g/km and 48.7mpg. This immediately puts the i-CTDi at the best-in class level, and it would take a toothcomb trawl through the tables to find a similarly-sized car with a similarly-sized engine that has such low emissions.
Only Volkswagen's 1.9-litre TDI PD, the Jaguar 2.0D and 1.9-litre diesel motors from Renault, Peugeot and Citroen come close in terms of emissions. Only the Jaguar engine comes close when refinement is factored in.
Even more good news for company car drivers is that it is Euro IV-compliant, which means no 3% benefit-in-kind tax surcharge, so the Accord, in saloon form at least, will sit in the 15% tax band for the foreseeable future.
Addressing the diesel question for the first time has allowed Honda to start with a blank sheet of paper, and the engineers have gone for an aluminium cylinder block which combines strength with lightness.
Transversely mounted, the Accord engine has a number of elements to ensure that running is as smooth as possible. These include two balancer shafts and a 'pendulum' engine mount system which allows the engine to rock and absorbs vibration. There is also an under-bonnet cover, undertray and bulkhead insulation for sound deadening, and a dual mass flywheel to dampen vibration further. No engineering stone has been left unturned in the quest for smoothness.
Key to the silky and efficient running of the engine is the 'continuously variable swirl control valve'. Located in the intake manifold chamber, this little valve controls the air flow into the cylinder, adjusting it according to the speed of the engine. A good air/diesel mix is key to efficient and smooth combustion and this valve maximises that mix, particularly at low speeds.
The issue of clutch wear rates is also something that is starting to trouble the fleet industry. With more and more drivers switching to diesel for the first time, they are being heavy footed on the clutch, where the extra torque of a diesel engine is putting a strain on the system, resulting in a shorter life. To counter this, Honda is using a self-adjusting clutch to give consistent feel and travel throughout its life.
Ken Keir, managing director of Honda UK, stressed the importance of diesel to the firm, particularly in the fleet arena. He said: 'This engine is really important to us for many reasons. In the past three years we have enjoyed growth of 28% with new products. The introduction of this new engine moves the game plan significantly forward for us. The diesel Accord is a major business opportunity and we are very excited about it.'
Honda hopes to sell about 3,000 saloons and 2,500 Tourers in the UK in a full year, with the majority ending up as company cars. This seems a conservative estimate, but the plant in Japan is scheduled to build 15,000 a year in total, despite capacity to build 30,000, so if things really kick off, the production line can be adjusted according to demand.
Honda's fleet and business sales department has been at pains to sell the Accord i-CTDi to contract hire and leasing companies, through which many of the cars will be supplied.
National leasing manager Andrew Wale added: 'Highly competitive leasing rates have been made possible through a combination of competitive list prices, excellent residual values and very low projected service and maintenance costs.' These rates should be available from all leasing companies during October and cars can be ordered from December 1. The on-sale date for the Accord diesel is February 1.
The i-CTDi engine will only be available in higher-end Sport and Executive models for the moment, aiming at user-choosers, and residual values look fairly strong. CAP Monitor predicts it will retain 38% to 39% of its cost new after three years/60,000 miles. This generally represents a one or two percentage point uplift over equivalent petrol Accords.
Prices start at £18,700 on-the-road for the Sport, rising to £23,300 for the Executive Tourer with 17-inch alloy wheels and satellite navigation.
Behind the wheel
The Accord i-CTDi has 251lb-ft of torque, which puts it at the top of the class, and 138bhp, which again is more than adequate.
But what most impresses about the Accord is how these figures translate into real-world driving. The Accord only uses a five-speed gearbox, when most of the competition, X-type excluded, uses a six-speed transmission. But according to Honda, the five-speed is more than adequate for its needs, and anyway, many manufacturers are fitting six-speeders to hide a narrow torque band.
It soon becomes patently obvious that five ratios are enough. The i-CTDi starts to wind itself up at about 1,000rpm, really gets going at 1,500rpm and keeps the same unwavering thrust going until 5,000rpm.
It does this without vibration, although the turbocharger whine is a little too intrusive. There is a decent acceleration, although much of its performance is masked by its refinement. Like the X-type 2.0D, it feels slower than many of the noisier, shorter-geared competition, but it isn't. It is just that the Accord does not make a song and dance about its rate of progress.
One of the main reasons that the engine is so good is a low compression ratio. Petrol engines run at about 10:1, while most diesels end up at about 20:1. The i-CTDi, due to its variable swirl and other technologies, runs at only 16.7:1, which means more refinement, less engine resistance to changing down gears, and a more petrol-like experience.
Because of the extra torque of the diesel engine, suspension settings have been revised slightly, but all that does is give the car the same easy-going nature of the petrol. This Accord is first and foremost a good, solid cruiser and, with the diesel unit, even more so.
It is a difficult thing to compare different sized engines, like comparing a heavyweight boxer against a flyweight. Volkswagen's 5.0-litre V10 is staggering and the BMW 3.0-litre straight six is fantastic but litre-for-litre the four cylinder, 2.2-litre i-CTDi engine could well be the best diesel engine in the world.
HONDA might not have wanted to build a diesel, but its engineers stoically slugged back that bitter pill and created a fantastic engine that reflects Honda's reputation as an engine builder par excellence. As a first effort, this is a staggering achievement.
Model: Honda Accord i-CTDi
Engine (cc): 2,204
Power (bhp/rpm): 138/4,000
Torque (lb-ft/rpm): 251/2,000
Max speed (mph): 130 (123)
0-62mph (sec): 9.4 (10.1)
Comb fuel consumption (mpg): 52.3 (48.7)
CO2 emissions (g/km): 143 (153)
Transmission: 5-sp manual
Fuel tank capacity (l): 65
Service interval (miles): 12,500
On sale: February 2004
Prices (OTR): £18,700 – £23,300
Tourer figures in brackets