TOYOTA'S desire to increase the sex appeal of its stalwart Corolla small car has left the door open for a multitude of larger and more powerful engine possibilities – including a V6.
At last week's 10th-generation (150-series) Corolla launch, the executive chief engineer for the project, Soichiro Okudaira, confirmed to GoAuto that the model's engine bay was designed to accommodate a V6.
"Everything from a 1.4-litre engine to a 3.5-litre engine will fit in the Corolla," Mr Okudaira said.
The 2GR-FE 3.5-litre quad cam 24-valve V6 is the basis of the Aurion sedan in Australia. It delivers 200kW of power at 6200rpm (204kW on premium unleaded) and has a torque peak of 336Nm at 4700rpm.
More tantalisingly, as most Aurion models top 1600kg, its 7.4-second 0-100km/h sprint time would be slashed in the circa-300kg-lighter (and more aerodynamic) Corolla.
If the Corolla V6 does get the green light, it is likely that a six-speed manual and six-speed automatic gearbox will be made available.
It is also likely that the part-time AWD system used in Toyota's RAV4 SUV will be utilised to channel the Corolla V6's outputs.
Mr Okudaira told GoAuto that his engineers concentrated specifically on strengthening the engine bay and rear floorpan to accommodate larger engines.
He also revealed that the independent double wishbone suspension set-up found in some overseas versions of the Corolla hatch (known as the Auris elsewhere) was devised primarily to house AWD hardware. A V6 with or without AWD would only ever be sold as an image-boosting niche model for the Corolla/Auris brand, to take on Volkswagen's Golf R32.
However, a Camry-powered Corolla is more likely to arrive in the next two years than the Aurion-engined version.
Based on the Japanese-market Blade model, the next Corolla Sportivo is expected to use a larger four-cylinder engine.
As Toyota’s standard 'world' engine (models as diverse as the RAV4 and Tarago use it in Australia), the 2AZ-FE 2.4-litre unit in the Blade develops 123kW at 6000rpm and 224Nm at 4000rpm.
In Japan the Blade is available in front or AWD models, and is linked to a constantly variable transmission.
This gearbox may also eventually be fitted to the regular 100kW 1.8-litre 2ZR-FE Corollas.
Mr Okudaira admitted that a CVT was the preferred gearbox solution to the outmoded four-speed automatic that is fitted to an overwhelming number of Corollas in this country.
According to Toyota Australia's chief product planner Doug Soden, the company is considering the possibility of a CVT, but is unsure as to the consumer reaction to this technology – despite the success of isolated models such as the Honda Jazz CVT.
"Although Australians have accepted it in light cars, we don't know how they would react to CVT in larger models such as the Corolla," Mr Soden said.
Meanwhile, the Di-D direct-injection four-cylinder diesel engines available in the European Corolla/Auris models – in 1.4-, 2.0- and 2.2-litre sizes – are still some years away from an Australian introduction, if at all.
"(The diesel engines) are under some consideration and discussion," a Toyota spokesman said.
However, Toyota Australia's senior executive director for sales and marketing David Buttner insisted that there would not be a diesel-engined Corolla before 2010.