VE under the skin: fast figures and fuel confusion

Holden has released performance and mass figures for its new VE Commodore. The announcements came as the company continued to drip-feed information about its critical new car via two days of engineering briefings this week.

While weight is up (see below), so is performance -- at both ends of the VE spectrum.

Holden's claimed 0-100km/h figure for the auto-only base Omega is 8.1sec. This is backed up by a 15.7sec standing 400m.

The top-shelf SS V with six-speed auto does the 0-100km/h split in just 5.4sec and the standing 400m in 13.7sec. These are fast figures by any measure and knocking on the doors of several HSV models which appear to have significantly higher claimed outputs than the SS V's 270kW.

Holden has now clarified the different fuels used in each set of power claims and the fuel consumption cycles: they are all different because of different market and legislative requirements! CarPoint unraveled this confusion by talking directly to Holden engineers.

The new L98 V8's 270kW/5700rpm (previously 260/5600) and torque of 530Nm/4400rpm (previously 510/4400) can only be achieved on 98 RON Premium Unleaded fuel. The fuel consumption tests as dictated by ADR's (Australian design Rules) must be undertaken on European specification unleaded which is 95 RON or higher.

Even though the new L98 will run on Australia's basic 91 RON unleaded, Holden told CarPoint that its peak power will drop by 7kW and torque will drop back by a significant 22Nm if 91 RON is used.

It is not the quantum of these reductions that are a concern, but where they occur. Generally, the losses are more noticeable at lower revs and will become even more pronounced under load or higher temperatures. If drivers push the engine harder to compensate for the loss of performance, then fuel consumption will almost certainly increase on the lower grade fuel.

The power and torque figures for the heavily revised Alloytec V6 engines are all measured using basic 91 RON unleaded fuel yet the fuel consumption figures are generated on 95 RON as stipulated by the relevant ADR.

Holden claims that it quotes the lower 91 RON power and torque figures to allow a direct and fair comparison with its main rivals which also measure their outputs on 91 RON unleaded. This means that both VE Commodore V6 engines along with their BF Falcon rival are capable of delivering higher power and torque outputs when filled with 95 (or 98) RON fuels.

Holden seemed confident that owners should be able to replicate its V6 fuel consumption figures on basic 91 RON unleaded within the confines of the fuel consumption test. However, it was conceded that under high temperature/high load situations such as with air-conditioning on at high speed or towing, the higher octane fuels may deliver better fuel consumption when the torque and power figures are beefier at lower revs.

There is another factor that makes direct comparison difficult. Until the start of 2006, manufacturers could measure their power and torque outputs by the DIN measurement. Manufacturers must now switch to the more conservative ECE measurement.

The fundamental difference to horsepower junkies is that the DIN measurement allows manufacturers to claim power and torque spikes (even if they only occur momentarily through the rev range) as maximum figures. The ECE measurement requires manufacturers to identify a power and torque peak then hold it for a full 60 seconds. If it's a very fine peak ‘blip', it won't be sustainable under this measurement forcing manufacturers to seek a more sustainable peak elsewhere in the rev range which is usually lower.

This explains why so many manufacturers appeared to lose power and torque in the Euro III changeover at the start of 2006. Holden's figures have all been brought into line with ECE measurements including V6 models.

Current HSV figures are measured using the DIN system so that the difference between the current Z-series 297kW claim and Holden's latest 270kW figure is not as high as the raw numbers suggest. This explains why the new SS V appears to post such outstanding performance figures for such a relatively modest claimed output.

HSV is expected to bring its figures in line with Holden's ECE measurements at the August launch of its new VE-based range. This will create a similar situation where HSV's relatively small increases in claimed power and torque figures will be matched by some rather more outstanding performance figures.