General Motors reveals Gen 5 V8

GENERAL Motors has revealed its more advanced Gen 5 LT1 V8 engine, a version of which could potentially feature in Holden’s facelifted VF Commodore from 2014.

The new 6.2-litre V8, which develops 335kW of power and 610Nm of torque, will sit under the bonnet of next year’s new-generation Chevrolet Corvette coupe in the United States.

Though based on the architecture of the 6.0-litre pushrod Gen 4 fitted to the current Commodore, the fifth-generation engine adds modern technology including direct fuel injection and continuously variable valve timing, making it not only more powerful but also more efficient than before.

Said to be the “most significant redesign” in the six-decade history of GM’s famous small-block engine, the all-aluminium LT1 has been designed to offer a broader power band, with torque delivery below 4000rpm claimed to rival the 7.0-litre LS7 V8 from the current Corvette Z06.

The new LT1 engine will appear for the first time when the seventh-generation Corvette makes its world debut at the Detroit auto show in January.

GM’s new Corvette enters production around September and is expected to go on sale in the US by the end of 2013.

Figures are not yet finalised, but GM expects the lighter new ’Vette will be the quickest naturally aspirated version to date, as well as the most frugal.

From top: Chevrolet LT1 logo Current-generation Chevrolet Corvette Holden Commodore VF prototype.

GM has indicated the car will be able to accelerate from zero to 60mph (0-97km/h) in less than four seconds and return highway fuel consumption of about 9.0 litres per 100km.

The new engine will only be dubbed LT1 when used in the Corvette, but GM says it will merely be the first of the new Gen 5 family of small-block engines destined for a host of GMC and Chevrolet models.

Considering the Gen 4 engine powers performance versions of the current VE Commodore, a Gen 5 unit could be expected to do likewise in the lighter and more frugal VF some time after its projected reveal in February and market launch a few months later.

However, since the Gen 5 will debut in the Corvette towards the end of next year – and therefore after the VF – the addition of the new engine to the Commodore range would likely come some months after its initial launch.

The restyled Australian-built VF is expected to be more aerodynamic and lighter – thanks in part to an aluminium bonnet – and feature fuel-saving features such as an electric parking brake and electric-assisted power steering.

Fuel savings are a major development parameter for the VF, with GM Holden chairman and managing director Mike Devereux on the record as saying the company is shooting for entry six-cylinder variants to use around 8.5L/100km.

VF will also likely feature an array of advanced safety technologies from the new Chevrolet Impala and a voice-recognition system featuring a broad Australian accent.

Although the current Commodore’s Gen 4 is available with cylinder de-activation technology – again a feature in the new Gen 5 – it consumes at least 12.2L/100km.

The LT1’s projected outputs would not only outstrip the current Commodore V8’s 270kW/530Nm (in manual), but also the 325kW/550Nm from the 6.2-litre HSV GTS.

Arch-rival Ford special vehicles outfit FPV offers a supercharged 5.0-litre V8 that equals the LT1 for power (335kW) but trails in torque (575Nm).

As we reported earlier this month, at least some examples of HSV’s upcoming ‘F Series’ line-up are expected to deliver even more performance thanks to a version of the Chevrolet Camaro ZL1 supercharged 6.2-litre V8 that delivers 432kW and 754Nm.

Corvette chief engineer Tadge Juechter said the LT1 engine achieved the “holy grail” of new engine development – greater performance combined with better fuel economy.

“By leveraging technology, we are able to get more out of every drop of gasoline and because of that we expect the new Corvette will be the most fuel-efficient 450-horsepower car on the market,” he said.

GM claims the LT1 is about 20kg lighter than the 4.4-litre twin-turbo V8 with similar output of an unnamed competitor – read BMW – and will help trim weight from the new Corvette and help create close to a 50:50 weight distribution.