SX4 diesel : Join the waiting list

Remember the ‘Men are back' campaign for the Maruti Suzuki SX4? The car filled an unmet need and possibly the campaign worked to Maruti's advantage, though there were many who thought that the tagline was sexist, rather than being sexy.

Maruti Suzuki is now taking the SX4's masculine positioning one step further with the introduction of a diesel-engine version. Again, here Maruti does run the risk of stereotyping the buyer profile of diesel cars. But, the fact remains that by sheer numbers diesel sedans are more popular amongst male buyers.

The SX4, like a few other competitors in the same segment, did miss a diesel engine dearly. Though the petrol engine variant has been clocking decent sales during the last about two years, the car had a sluggish start because acceptance levels, back then, were low for a premium sedan from Maruti and also because it lacked a diesel option. The Suzuki Swift DZire DDiS is a good example of what a diesel engine can do to a model's prospects.

So, after about one and a half years of design and development work, four lakh kilometres of endurance testing, 50,000 kilometres of cross country validation and 4,500 hours of engine validation on the dynamometer, the new SX4 DDiS diesel makes its debut.

Souped up

What the joint team of engineers from Maruti and Suzuki have done is essentially to take the same 1.3-litre common rail diesel engine that is currently available in the Swift and the DZire, and shoe-horn it into the SX4's engine bay. But, before they did that they souped up the engine so it could offer a more ‘manly' performance.

The new Super Turbo 1.3-litre DDiS engine thus delivers a 20 per cent increase in power and a modest 5 per cent increase in peak torque compared to the same engine's performance in the Swift.

The first addition has been a variable geometry turbocharger that has replaced the fixed geometry turbocharger. This new turbocharger features vanes that change their angle based on requirement to ensure optimum air flow to the engine. Depending on the driver's input, a remapped, new generation engine electronic control unit (ECU) ensures that the demands placed on the engine (through the throttle) is instantly communicated to components such as the variable geometry turbocharger.

The other change is the new, second generation high pressure fuel injection system that delivers fuel at up to 1,600 bars, even higher than the Swift DDiS' 1,400 bar. The high pressure pump has an in-built flow control mechanism to improve efficiency. Both these features optimise performance across the entire engine rpm range. In the engine chamber too, the high pressure pump breaks up the fuel to ensure more complete combustion, boosting both power delivered and emission reduction measures.

Performance

The reworked 1,248cc engine now delivers a peak power of 90 PS at 4,000 rpm and a maximum torque of 200Nm from a low 1,750 rpm. The diesel SX4's engine is capable of powering this 50 kg heavier (compared to the petrol SX4) model from standstill to 100 kmph in 14.5 seconds.

Maruti Suzuki engineers have also endowed the engine with a few other changes. For example, the Super Turbo DDiS' pistons are gallery cooled for better performance and it also uses lower viscosity engine oil (SAE 5W40) to improve lubrication.

On paper, and despite the additions, the 1.3-litre engine from Swift seems inadequate for the SX4. But, my test drive of the new SX4 diesel put to rest such doubts. Yes, we motoring journos will never really be satisfied enough, but it is a task for car makers to strike the right balance between performance and fuel efficiency.

I test drove the SX4 diesel within the increasingly congested streets of Delhi and on the Greater Noida expressway.

The engine felt like a fair choice. There is enough power available and the pep in the SX4's stride is better than the Swift DDiS'. The new SX4 diesel is about 13 per cent heavier than the Swift DDiS. But ably assisting the more powerful diesel engine in the SX4 is the new five-speed manual gearbox.ith more optimised gear ratios and a new detent pin technology that provides assistance for smoother gear shifts, the transmission is a delight to use. A short throw gear shift stick included, the package is perfect for fatigue-free performance. This is a clear improvement over the Maruti gearboxes we have been used to in the past. The overall drive quality of the new SX4 DDiS is very peppy and similar to the Swift diesel. Power delivery is very linear and available on demand all the way up to 4,000 rpm, after which it dips to about 78 PS when the engine hits the redline. The diesel SX4 is being offered only with the 5-speed manual transmission, though the petrol counterpart is also offered with a 4-speed automatic gearbox.

Refinement

The DDiS diesel engine was a fairly refined unit and was already not very audible in the Swift and in the many other cars that Fiat India and Tata Motors too employ. In the SX4, one of the most surprising observations that you'd make when pushing the new Super Turbo DDiS on the highway is the remarkably low noise and vibration levels in the passenger cabin.

The entire NVH packaging has been reworked for improving the quality of the ride and in-cabin noise levels. There is almost no discernable vibration at the steering wheel or pedals. There is almost a complete absence of the characteristic diesel clatter too inside the cabin during idling, which is usually the noisiest of the entire driving cycle. Engine noise does creep in at speeds of over 120 kmph and if you are still accelerating hard. I peep into the hood and find that the thicker padded insulation and noise isolation packing are evidently the reason for the quieter cabin. The new SX4 Super Turbo DDiS is only about 50 kg heavier than its petrol counterpart. Of course, much of that increase in weight is in the front and Maruti Suzuki engineers have tweaked the suspension to provide for the additional weight and to maintain the car's driving dynamics. The ground clearance and the suspension set up is the same as in the petrol engine. To improve stopping performance, the new SX4 diesel's brakes also get a boost.

The ride quality of the SX4 hasn't changed despite the change of powertrain. The suspension continues to soak up pot-holes and keep the passengers in the cabin fairly composed and comfortable. When pushed too hard at the turn or thrown into corners, there is very mild body roll, but nothing that can make it discomforting for the driver. High speed straight-line stability is good for a car in this class. For whatever reason Maruti thought fit, it has decided to make the petrol and diesel SX4s look like clones. Except for the DDiS badge there is nothing to distinguish the diesel from its petrol sibling. There is no change to the exterior design. There is not going be any additional body colour options too…at least for now. The same goes for the interiors. The choices of trim, upholstery, layout and colour theme too are the same as the petrol SX4. To refresh your memory about the SX4's exterior design and interior layout just take a longer look at the photos here. Safety features are also similar to the petrol SX4.

Bottomline

The one chink in the SX4's armour will get plugged with the introduction of the diesel version. To make it even more attractive, Maruti Suzuki claims that the SX4 diesel can deliver a fuel efficiency of 21.5 kilometres per litre (certified as per CMVR rules). This is said to be 8 per cent more than comparable cars in the class. During times of fuel price hikes, such as these, this must be music to buyers' ears.

Further, Maruti has upped the ante by getting the SX4 diesel certified as ‘OBD-2' compliant. The SX4 Super Turbo DDiS is said to be the first car to be certified. OBD is short for On Board Diagnostics, and OBD-2 certified car should inform the car user of any malfunction in the emission control system, which may lead to undue increase in exhaust emissions. This is meant to act as a measure of self-monitoring and in the SX4, the warning message is delivered in the form of an orange icon on the instrument cluster. The new SX4 diesel will be available in VDi and ZDi variants and I expect it to be priced between Rs 7.75 lakh to Rs 8.70 lakh (for ZDi with leather seats).

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