Here is a car that looks unremarkable yet hides a remarkable engine – the Honda Accord V-6. The headlines are all about this engine that can run as a three-cylinder, four-cylinder or six-cylinder, which it does, and very well at that. This is a concept that could help all high-performance engines give better fuel consumption.
What that does not tell you is that this is a very sporty V-6,and that the rest of the package is much more sporty than you would expect. Power output is 270 bhp at 6,200 rpm. Yet here is a car you hardly notice out on the road.
Once you get your chance to put your foot down, you get the shove in the back that tells you this is a sporty engine. Maximum torque is produced at 5,000 rpm, so for best results you need to keep the very quiet engine spinning. Even so as the revs build up, a throaty roar tells you that you're motoring.
Use three, four or six cylinders
Let's start with the technology. Unlike previous Honda V-6s, this new 3.5 liter engine has a 60-degree angle between banks, which gives better balance and saves space. There are thin cast iron liners in the aluminum block.
Although there are four valves per cylinder, there is a single camshaft (SOHC) per bank which reduces the width of the heads, and reduces friction.
Weight is also saved because the exhaust manifolds are integrated into the cylinder heads.
Multi-mode cylinder operation
When power is required, such as when starting the engine, accelerating, or climbing hills, all cylinders are used. For cruising at moderate speeds, the engine runs on three cylinders. For faster cruising and climbing mild hills, four cylinders are used. All this happens completely seamlessly, without the driver or passenger being able to detect the switch. Amazing.
This idea is not new; various firms have done it in the past, including Mitsubishi which had a four-cylinder engine which could operate as a twin in the 1980s, but it was not a success. Nowadays, the technology has advanced though.
The i-VTEC system is the latest version of Honda's VTEC variable valve lift and timing system, which has been in use for about 15 years. The system is operated when plungers are actuated hydraulically to set one set of cams in motion instead of the other one.
In this new version one set of cams is used for low-speed operation and another for high speed operation as before. In addition, to deactivate some cylinders, the system closes both intake and exhaust valves of the relevant cylinders. This reduces pumping losses while preventing the cylinders from operating.
The sparking plugs keep firing in all cylinders to maintain their temperature and prevent fouling.
One reason why you cannot detect the changes is that there is a active control engine mount which provides motion to cancel out the shudder that might otherwise occur. Pretty snazzy, and it definitely works.
Inside the Accord is plenty of technology
Inside the car, you are aware of the technology, which in addition to the usual ABS, includes traction control and stability control. There is a navigation system which has a large screen. When you engage reverse, it activates a rear view camera which shows you what is behind.
The view is good, except when the camera gets rain on it, but it sometimes makes things seem further away than they are.
Good navigation system
Even so, this is an excellent navigation system, once you work out which way to operate the knobs. Not only does it work well, but is much simpler to operate than many competing systems.
The leather seats are comfortable with reasonable lateral support, and the conventional instruments are clear and large.
But the big question is how can front-drive handle 270 bhp? Well, the short answer is that it would be a real handful without traction control and stability control, which cut the power if you put your foot down too hard when coming out of a T-junction fast, for example.
The system does allow a little wheel spin, and the Michelin Energy 50 per cent profile tires do squeal a bit if you corner energetically.
Smooth and quiet engine and auto box
Out on the road, I was immediately impressed by the smooth engine and transmission, which delivers a good amount of power smoothly. The ride is pretty good, and the steering is well-weighted. So far so good.
Drive the car as an ordinary sedan, and it behaves well. But what happens when you want to hustle a bit? The first thing you need to do is to select S instead of D for the auto, and you now have full manual control through paddles at the wheel.
This works very well indeed, really holding the lower gears, and allowing the engine to rev right up to 7,000 rpm, which gives 44 mph (70 km/h) in first, and about 75 mph (120 km/h) in second. Third is geared for about 120 mph (190 km/h). This is a five-speed auto, so you don't get quite the good match of engine speed to road speed you get with a six-speed auto.
Even so, the performance in 'S' is very good indeed, with good engine braking. If you imagine that the Accord is rather a dull car, this engine will completely change your ideas.
Front-wheel drive handling
You can't get away from the laws of physics though. Although the Accord V-6 handles pretty well, when you enter a corner the car does not turn in quickly as with a smaller car, or one with rear drive. There is just too much weight up front.
So, you turn in quite early to pull the nose around, and on slow corners the understeer and roll build up progressively as you would expect. Lifting off reduces the understeer in a very quiet way, without real tuck-in.
Even so, when I drove the Accord V-6 over one of our test routes I was impressed with the way that the Accord tracked through the long and short curves quickly with no drama. You can find plenty of power when you want it so long as you keep that engine spinning, and this is where the S mode makes a big difference. Select a gear and there you stay, with the engine revs building up or dropping on command.
Is this a real sports sedan? Not quite. It has quite a bit of power, and despite peak torque being produced at a high speed, you are not aware of the engine coming on cam. The power delivery is pretty good. The Accord rolls rather too much and there is inevitably electronic intervention to keep control of that power going through the front wheels.
Very smooth, surprisingly quick
Overall, though, this Accord V-6 is a very smooth and quiet car that can be turned into a surprisingly sporty car at the press of the pedal and the pull of the gear lever back into S.
And cylinder switching works
And what about that cylinder switching? Well because you don't feel or hear it, you forget it. However this works. I reckon the fuel consumption is about 10 per cent better than you would get without it, and that is worth having, as Honda's technology usually is.
