TOKYO MOTOR SHOW: Honda's drivetrain future revealed

Honda has unveiled three new turbocharged petrol engines and an eight-speed dual-clutch-style torque converter-based transmission ahead of the 2013 Tokyo motor show.

The three- and four-cylinder direct-injected DOHC units range in displacement from 1.0 to 1.5 and 2.0 litres, and will power a range of models from small hatches and SUVs, through to the next-generation Civic Type R.

It is anticipated that the first application of the lower capacity engines will come as part of the drivetrain package for the upcoming Jazz-based Urban SUV, which will make its production premiere at tomorrow’s Tokyo motor show. The model is also confirmed as offering diesel and hybrid powerplants.

The 1.0-litre three-cylinder VTEC TURBO forms the base of Honda’s next-generation compact engines.

It develops 95kW and 200Nm and will likely replace most smaller four-cylinder engines in Honda’s current line-up -- up to and including the current 1.8-litre petrol.

Compared to this engine, Honda says its triple develops 45 per cent more torque and 20 per cent better fuel economy.

A quick drive of the engine in a prototype ‘mule’ proves Honda isn’t exaggerating. The engine provides brisk step-off acceleration and strong in-gear pull. It is flexible and remarkably smooth for a triple, with hushed NVH characteristics and a distinctive off-beat warble.

Compared to other three-cylinders sampled in this category it is impressively linear. There’s little lag in its lower reaches and no noticeable slack as the revs build. Even under the weight of a Civic hatch, the triple proved outstandingly strong, and had no trouble accelerating to speeds nearing 160km/h.

The mid-spec 1.5-litre four-cylinder VTEC TURBO engine is anticipated to replace current petrol engines ranging in capacity from 2.0 to 2.4 litres in displacement.

It makes 150kW and 260Nm and, like the three-cylinder offering, utilises a fixed-geometry turbocharger to achieve what Honda says is a “good balance between high output and torque”.

Motoring.com.au was also offered a brief drive of this unit, which proved potent, though not entirely refined. The mid-grade four-cylinder offered fluid acceleration from around 2000rpm, revving freely to around 6500. The acceleration was brisk, but uncharacteristicly coarse-sounding, with a dry mechanical note to the engine.

It was, however, impressive to note that in an Acura RLX (a vehicle similar in size to the Honda Accord Euro) this engine felt unflustered by the vehicle’s weight. It was not as brisk from standstill as the three-pot, but managed excellent overtaking performance in a straight line, dashing from 80 to 130km/h effortlessly.

Despite the merits of the two smaller engines, the undisputed flagship of the new VTEC TURBO range is the 2.0-litre four-cylinder. It will likely premiere with the next-gen Civic Type R from 2015.

Developing “206kW or more” and 400Nm, the engine also features new technologies for Honda, including an electrical wastegate for the turbocharger, cooling gallery-style pistons, a cooled cylinder-head and high-tumble intake port design.

The Euro 6-compliant unit also offers fuel-saving technologies such as an idle-stop function.

We sampled the 2.0-litre unit in a Civic Type R prototype for one very quick lap of Honda’s Tochigi R&D circuit. There’s virtually no lag evident as the car grapples for traction, accelerating harder again once the needle passes 4000rpm.

From here to a 7000rpm cut-out, the intake noise presents in a similar gush to that of the Renault Megane RS 265, but there’s little exhaust character to speak of.

‘Pull’ through the wheel is evident but not overpowering as the throttle is nailed to the floor, and by the top of fourth gear at full noise the 2.0 VTEC TURBO has reached its 200km/h electronic limiter.

Honda says that, although the 2.0 VTEC TURBO will likely make its debut in the new Civic Type R, it could go on to replace a myriad of petrol engines, up to and including the current 3.5-litre V6, as found in the full-size Accord locally.

It was a mule version of an Accord that also gave us a chance to sample Honda’s new eight-speed torque converter
‘DCT’. The unit is aimed at replacing the aging five-speeder found across much of Honda’s line-up, though besides the drive itself, details were scarce.

The transmission eliminates entirely the take-up lag usually present in dual-clutch units, and did not appear to ‘surge’ at low speeds, or in reverse.

Under acceleration the DCT swapped quickly and seamlessly through its ratios, the changes imperceptible at moderate throttle loads, bar of course for a dip in the tacho needle.

Under heavier throttle inputs the transmission reacted near-instantly, promptly selecting the correct ratio for the desired input and road speed and accelerating accordingly.

Even under heavy throttle, the transmission did not ‘bang’ through the gears in the way a traditional dual-clutch often can. It’s far more refined, but no less effective.

A very brief lap of the track could only tell us so much and Honda was coy on detail, but the manufacturer did say the transmission was capable of delivering acceleration performance 10 per cent faster than a conventional dual-clutch transmission while also being eight per cent more efficient.

It is unknown just where the transmission will first appear in production form, though with a torque ceiling of 270Nm its applications are somewhat limited.

It is anticipated Honda will divulge more information on the future of its drivetrain technology at the Tokyo motor show this week.

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