GM To Debut HCCI Technology on Opel Insignia

Incidentally, I've taken another look at the Vauxhall Insignia and it's a good looking car. I'm impressed. I just hope the interior will be better than the current Vectra. Vauxhall/Opel interiors really are poor.

@ Paul Niedermeyer "A gas ICE engine runs most efficiently (least wasted energy) at fairly high power levels. That’s why small engines working relatively harder are more efficient than a lazy big engine." Don't think so. The most "efficient" running of a gas ICE engine occurs at low rpm and wide throttle opening, assuming some attention has been paid to valve timing and lift, so that one is not too far from the peak torque. Why? 1. Low pumping loss because the throttle plate is nearly out of the way of prevailing airflow into the cylinders at wide throttle opening, making it more diesel-like, because they have no throttle at all. 2. Low rpm minimizes friction losses with respect to piston rings sliding along cylinder walls, and low rpm is easier on bearings and oil films due to the lower dynamic loads. In addition, a large cylinder has a smaller surface area compared to its volume than does a small one, so less heat is rejected proportionally to the cooling system, and more goes into mechanical work. So, fewer bigger cylinders are more efficient for a given displacement. All this I learned 40 years ago on an engine dynamometer. Austin engine of 948 cc, versus a Volvo of 1780 cc and a 272 cu in Ford V8 The Ford had the least specific fuel consumption, that is pounds of fuel consumed per horsepower per hour, which cheesed me off, because I was a Volvo enthusiast. If you think about it, it makes sense. The trick is really to optimize engine size versus rpm required, and the weight of the resulting engine block, which dictates the size of the vehicle it is installed in. I think we've all heard about GMs aluminum V8s. They're pretty damn efficient being physically small and able to produce enough power to cruise a car at 70 mph at about 12 or 1300 rpm, with a relatively wide throttle opening. On the aeronautical side of things, during the second world war, both the RAF and the USAAF had to try to persuade pilots to minimize rpm and maximize propeller pitch with WOT to maximize cruising range. Apparently, most guys just wanted to wind the engines up and didn't like "lugging" them. Nice thought, but wrong if you want to get back home again. In my new car, one can watch the fuel consumption in real time. At 40 mph, from 2nd through 5th, the mileage increases (consumption lowers) as one goes up each gear, and the rpm lowers. And this happens even though only second gear is anywhere near the published maximum torque peak rpm for the engine, (although it does have variable intake valve timing). That's the actual real world for you. As a further point, people have complained about the mileage of a Smart Car versus the Honda Fit or Toyota Yaris. You have to flog the Smart to keep up, while the "big" lazy engines of the Japanese cars are just easing along by comparison. So what does HCCI actually do again? Ah yes, work at low rpm like a diesel, but over a very limited rpm range. Makes sense to me.

Landcrusher; I think Ferrari, Mercedes Benz, Audi, and BMW would argue your point that GM makes the best V8 engines in the world.

Matthew, They would have a good argument until it came time to discuss the definition of "best". Ya, I know they can make some really great numbers, but reliability is REALLY big for me, along with long term cost of operation. My experience says that GM's eights are as reliable as anyone elses modern eights, but they are a lot cheaper in the long run. Too bad I can't trust the rest of the car to be better than those mentioned by you. Well, okay, GM electrics are better as well. I would rather buy a BMW than any of the cars you added, and rather than a GM, but I avoid their 8 cylinders and go with the straight sixes. They make great sixes. Until Honda makes an eight, I will still consider GM top dog in that arena.