Vauxhall Vectra 2.2 HCCI (Insignia...)

**Penfold101** · 22nd May 2008, 12:39

Taken from the latest Autotrader...

It’s the most exciting family model that has ever worn the famous Griffin badge – and the Vauxhall Insignia is getting an engine to match!
Auto Express has been given early access to a hi-tech new petrol unit that will appear in the forthcoming Ford Mondeo rival, and it promises an amazing blend of performance, fuel economy and low emissions.
It’s called HCCI – the initials stand for Homogenous Charge Compression Ignition. And the new system will join Vauxhall’s line-up of small-capacity turbocharged petrol and diesel ecoFLEX engines to provide the Insignia with an unbeatable range of environmentally friendly powerplants.
An HCCI engine is effectively two motors in one. At low speeds, it means a petrol unit can work just like a diesel. This in turn increases efficiency – the overall result is a 15 per cent improvement in fuel economy.

We drove a 154bhp 2.2-litre Ecotec-powered Vectra fitted with the HCCI system. Although there are no official figures, it should return 43mpg (up from 37mpg), while emissions are set to fall by 30g/km to only 150g/km.
Engineers claim that they are not yet satisfied with the level of refinement offered by this version of the new car. However, the most obvious difference is the transition from a quiet, diesel-like rattle at low throttle to a normal petrol engine hum when you put your foot down – there’s no obvious jerk in power delivery.

Drive gently, and the engine stays in HCCI mode, although the slightest squeeze of the accelerator moves it immediately into conventional spark ignition running. After this, it takes a while for the powerplant to switch to the HCCI settings – something engineers at the firm say will improve once they’ve revised the control software.

When all the bugs have been ironed out, the 2.2-litre unit will mean the Insignia is not only a fast car, but also fuel-efficient and clean. And if HCCI is the future for petrol engines, things are looking very bright.

There’s no doubt HCCI brings great benefits. Even though the car we drove was a prototype, it feels remarkably close to production. While work still needs to be done in refining it, the smooth power delivery and gains in fuel economy are clear. HCCI is some way off – bosses at Vauxhall won’t commit to a production date, but we’d guess it will be another two years away. Yet it shows there’s plenty of life in the petrol engine yet.

**Big Sig** · 22nd May 2008, 12:51

Oooo I can't wait! its about time for a decent size petrol engine with dooe economy!

**glenboy** · 22nd May 2008, 13:19

Sounds a great motor,bring it on.....

**ccsnet** · 22nd May 2008, 13:38

Intresting....

Terran

**Hideous** · 22nd May 2008, 14:00

If there were more bhp it'd be very interesting. 154 bhp isn't enough to tempt me away from my diesel.

**Penfold101** · 22nd May 2008, 14:03

What petrols lack is the torque - that's what I like about my diesel... However, if the cost of buying the diesel is so much more than the petrol, I might be tempted...

**Ste** · 23rd May 2008, 13:13

I wonder how they are achieving HCCI at low engine speeds.

Normally petrol doesn't ingnite under normal compression ratios (typically around 9-11:1)
So, in order to get CI operation, the compression ratio would need to be increased, and then during 'normal' operation it would need to change back to a more realistic ratio for SI. Is it direct injection or port injection?
Variable compression ratio is not new, but it would be interesting to know more about the alleged fuel economy increase. Eg, compared to what and over what cycles??

**john_k_sri** · 23rd May 2008, 17:39

Originally Posted by Ste

I wonder how they are achieving HCCI at low engine speeds.

Normally petrol doesn't ingnite under normal compression ratios (typically around 9-11:1)
So, in order to get CI operation, the compression ratio would need to be increased, and then during 'normal' operation it would need to change back to a more realistic ratio for SI. Is it direct injection or port injection?
Variable compression ratio is not new, but it would be interesting to know more about the alleged fuel economy increase. Eg, compared to what and over what cycles??

Ste, from this week's Auto Express: "HCCI units direct some exhaust gas back into the cylinder to heat the incoming petrol-air mix, so it ignites as it is compressed (and further heated) by the piston".

I don't begin to understand any of it, but maybe you can care to comment on the feasibility of the above. To be fair VX say that they have yet to perfect the system, and in particular the transition from HCCI to conventional spark ignition at higher revs.

**benny** · 23rd May 2008, 18:06

sounds a good engine to me ..and no worry of cam belt or chain failure as i belive from reports in the vx world this new lump has no cam shafts uses electric valves .....wonder how good there gonna be tho on a vauxhall after 20k only time will tell what new faults they can think up ....

**Ste** · 23rd May 2008, 19:55

Hot EGR, normally it is cooled.

To be honest, and going on what has been said, it sounds like the article is full of sales speak - ie not technical.

HCCI is notoriously difficult to control and only works for a limited engine operation range (ie speed and load) - more tecky info would be welcome.