Hyundai reveals direct-injection petrol engine

HYUNDAI has released details of its upcoming direct-injection four-cylinder petrol engine.

A first for the South Korean brand, the 2.4 Theta II GDI (for Gasoline Direct Injection) is earmarked for the brand's Sonata medium sedan replacement, which is codenamed the YF and will wear a new name when it arrives here in the first half of 2010.

The GDI engine could also power the ix35-badged replacement for Hyundai's top-selling Tucson SUV, which will be launched in Australia early next year with a new 2.0-litre turbo-diesel engine.

Based on the existing Theta II four-cylinder petrol engine family, which features variable valve timing, the GDI delivers 150kW of power at 6300rpm and 245Nm of torque at 4250rpm, and features a high compression ratio of 11.3:1.

This compares to the current Theta unit’s 127kW at 6000rpm, 225Nm at 4000rpm, and 10.5:1 compression ratio.



The GDI system positions the fuel-injector hardware inside the combustion chamber for improved precision over a conventional multi-point injection set-up as per the old Theta engine. Fuel pump pressures of up to 150 bar result in better control over the combustion process.

Lower emissions are the upshot, since there is a two-phase injection system that specifically reduces the load on the catalytic converter during cold-start driving when it has not had a chance to properly warm up and operate at peak efficiency.

As a result, according to Hyundai cold-start emissions plummet by up to 25 percent, making the GDI engined vehicle equipped to meet the California Air Resources Board's ULEV-2 and PZEV standards.

Fuel consumption improvements in the vicinity of 10 per cent are also a GDI high point, so working from the existing Sonata 2.4L’s 8.4 litres per 100 kilometre combined average rating, we can expect the new model to fall below 8.0L/100km.

Hyundai has slashed internal friction paths within the engine by implementing measures such as new types of surface coatings and a cooling jet that sprays oil over the piston walls.

Other advances include a new three-stage variable induction system dubbed VIS thatat improves engine breathing, a quieter and more durable dual variable valve timing system, a stiffer engine block, a redesigned crankshaft, and a lighter catalytic converter. “The Theta II GDI convincingly demonstrates our parent company’s advanced powertrain engineering capabilities,” Hyundai Motor Company Australia’s sales and marketing boss Kevin McCann stated.

“Developed with a budget of AU$160 million, over a research period of almost four years, the new 2.4 Theta II will make its debut in the first half of 2010, initially in the all-new mid-sized sedan codenamed YF – beating the mid-size sedan competition with this exciting new technology – but will subsequently be expanded into other models.” In the meantime, a hybrid system known as Hyundai Blue Drive will be available in the new Sonata (which will be followed 12 months later by a European-oriented mid-sizer codenamed VF and dubbed the i40), in some global markets.

But whether the lithium ion battery-fitted eco model comes to Australia is not known at this stage.

“We can’t confirm what technologies will be introduced on the YF until launch,” said HMCA PR and product communication boss Ben Hershman.

“But some may not be available for Australia. Hyundai must make sure there is sufficient demand for these items (before committing to introducing them to a market like Australia’s),” he added.