A few years ago, the German Green Party challenged car makers to produce a 'three-litre' car. That resulted in widely varying approaches to the problem - just how do you make a car that sips a mere three litres of fuel every 100 kilometres, the equivalent of 94mpg? In Germany, Volkswagen's approach was to slip a tiny three-cylinder diesel into a specially lightened, part-aluminium Lupo. There were also 'special' three-litre versions of the Seat Arosa and Audi A2.
In Japan, however, engineers reject the idea of using small, diesel engines. They reckon the 'hybrid' approach, using a combination of petrol and electric motors, is the way forward. The result is cars like the Honda Insight and Toyota Prius. Honda, regarded by many as Japan's most innovative car company, came up with the Insight - which is quite different from the Prius. It's an unusual little aerodynamically efficient two-seater coupe, made from aluminium alloy. The Honda is a 'serial hybrid' powered by a one-litre, three-cylinder petrol/electric motor.
The major difference between the Toyota and the Honda is the mechanical design. While the Prius has separate petrol and electric motors, the Insight combines the two into one unit that Honda calls an Integrated Motor Assist system. Apart from three large electric cables attached above the clutch, it looks much like any conventional petrol engine and gearbox combination.
The petrol section incorporates all sorts of things that Honda, renowned for superb engines, has developed over the years including variable valve timing, four valves per cylinder and lean-burn combustion. The engineers have even found a way of integrating the exhaust manifold into the cylinder head so that the catalyst (which neutralises noxious emissions in the exhaust) heats up more quickly and goes to work sooner.
The little electric motor doubles as the starter and is neatly sandwiched between the petrol engine and gearbox. Unlike the Prius, whose petrol engine stops when the car is able to run solely on the battery-powered electric motor, the Insight engine runs all the time. The 44lb battery pack lives in the back (the main reason why there are no rear seats) nor is there much luggage room.
The dashboard layout resembles that of other modern Hondas. However, you'll find extra battery charge and fuel economy displays in the all-digital display in front of the driver. There is very little stowage space in the cabin for oddments.
Honda's traditional reputation for excellent reliability is just as valid with an Insight as with any other model in the range. There are a few minor things to watch out for. On pre 2001 models the two quick release fasteners that hold the rear wheel skirts on were made of uncoated steel and tended to rust more or less instantly. If left unchecked the skirts fall off. 'Check Engine' warning lights on the dash usually mean the oxygen sensor is crying wolf and your Honda dealer will know how to remedy this.
The standard fit stereo is unremittingly puny and many owners replace it as a matter of course. If your install can't connect to AM stations it's probably because power hasn't been supplied to the dinky AM frequency amplifier that's located in the base of the antenna.
The Insight is designed to cut out at idle but many do not. This can be due to any number of reasons. Investigate the following points.
Is the climate control set to Auto mode? If so, try setting it to Econ mode instead. Auto mode disables the idle stop feature.
Is the climate control set very high or very low? The Insight may not enter idle stop mode if the interior temperature has not yet stabilised at the temperature you've set it to. To verify whether this is happening, you could temporarily turn off the climate control entirely, and check whether idle stop now functions.
Is defogging / defrosting mode activated? If so, the engine will continue running.
Are you pressing the clutch all the way to the floor and/or shifting into neutral? If you immediately shift into first when coming to a stop, this will make the car think you want to go again right away, and the engine will never shut off.
The engine will only turn off after it has reached operating temperature. You should expect the engine to run for at least a minute after a cold start.
Is the battery level at or very close to empty? In this situation, the engine will continue to run to recharge the battery.
If all of the above conditions are satisfied, the problem is most likely that idle stop isn't functioning due to the exterior air temperature sensor being disconnected. Some Honda dealers are not aware of this sensor, and so haven't been connecting it when they should. This sensor is located behind the grill, in front of the radiator and, if air conditioning is installed, in front of the air conditioning condenser. If its wire is hanging loose, just reconnect it, and this should solve your problem.
(approx prices based on 2000 Insight) Spares prices for the Insight are a mixed bag. A starter motor is a heady £244 and a windscreen will cost over £200 including seals. A clutch looks reasonable value at around £130 whilst a front headlamp is an affordable £71. The battery pack is covered under the terms of warranty but Honda are currently looking at offering a lifetime guarantee on this part.
When you're driving gently, the 68PS petrol engine does all the work while the electric motor becomes a generator and charges the batteries in the boot. When you need faster acceleration, the electric motor uses the battery power to give the petrol engine a hand, boosting power to 76PS and increasing torque (pulling power) from 91Nm at 4,800 rpm to 113Nm at a low 1,500rpm.
It's a bit like two riders on a tandem bicycle. When it's level, the one in front does all the pedalling while the one behind puts his feet up and 'recharges his batteries'. When they reach a hill, the one behind gets on the pedals, too. As a result, Honda claims that the Insight has the performance of a conventional 1.5-litre petrol car - yet returns 83 miles to the gallon. Some tests have questioned whether the Insight is indeed significantly more economical than the latest Clio or Lupo diesels and in normal driving the difference can be marginal. Those who are used to the arcane practices of true economy driving can eke over 100mpg from an Insight but it's about as much fun as subsisting on an eggy bread diet.
Apart from the fact that the engine stops when you come to a halt and restarts almost imperceptibly when you push the throttle or engage first gear, the Insight is no different to drive than a petrol car. Japanese buyers get a CVT automatic but UK-bound cars have a conventional five-speed manual gearbox. If battery power is low, the stop/start system is suspended until they're recharged.
The Insight accelerates to 60mph in 12 seconds (about par with a conventional 1.5-litre petrol hatchback) and goes on to 112mph, so it has no trouble keeping up with the traffic. The little three-cylinder engine also sounds quite characterful, convincing you that you're going faster than you are. Handling is also fun, proving that environmental responsibility needn't always go hand in hand with a miserable experience behind the wheel.
The Insight is a car you'll either rave about or fail to see the point of. One disgruntled ex-owner sniffily claimed he should have bought a motor bike, as the Insight carried the same amount of passengers and luggage, returned similar economy figures but was significantly slower and more costly to purchase. For others it's an urban dream come true, a supremely economical and resolutely modern scoot that sidesteps congestion charges and is fun to drive. As a used proposition the Insight's day may well be coming.