The other issue with petrol is the propogation speed of the flame front, diesel is not a problem, try the same thing with petrol and you’ll get “knocking” and blow the bearings out of the thing, and there is only so much you can do, traditionally, to slow down the flame propogation front, traditionally an alloy head absorbed more free electrons and slowed it down that way, compared to an iron head.

As I know *nothing* about the engine in question I’m guessing they have solved the knock issue by some sort of fancy combustion chamber design and some sort of fancy metered direct injection system, then you have a compression ignition petrol (even if you use a spark or glow plug to initiate combustion) engine which due to the higher compression ratio is closer to a diesel for torque, so if we say for example that a 2 litre diesel pulls as well as a 3 litre petrol, now maybe a 2 litre diesel will pull as well as a 2.2 litre hcci petrol.

Lower compression means lighter build weight / quality / cost.

but it is STILL a heat engine, and if it is based on poppet valves and reciprocating pistons, that is about as good as it gets, 60% of the energy in the fuel is going to go down the pipe as heat.

Perhaps a 1300 cc hcci will do in place of a 1950 cc normal petrol engine, so I can see the economic case for it.

Dowsides are it is going to be a fucking bitch to work on and maintain compared to an OHV spark ignition 2 valve petrol lump.

Upsides are a 3 litre hcci celica would haul ass

Connections with electric vehicles, none, it doesn’t change anything, rolling resistance of a tesla isn’t much different than any other similarly sized and weight car, it can’t be, ditto aero resistance.

The downsides of the electric car is the IC engine has a fuel tank that costs less than 100 bucks to make, and said tank can be charged at a rate measured in megawatt/hours per minute, while electric is stuck at the *****very***** low end of the kilowatt/hours per minute rate….

The ONLY case for an electric vehicle is someone operating a fleet in london, they beat the congestion charge and they have a site to park and overnight charge, nota bene, electric VEHICLE, not car.

hcci is “just” going to be a more efficient way of burning gasoline in an IC engine, not that that is anything to be sniffed at, but we are talking about something on a par with fuel injection or electronic ignition, rather than the invention of the poppet valve.

Consider the hayabusa, the engine has to be relatively light, it’s 1,300 cc and 175 bhp, so 7.4 cc per bhp.

The dodge hellcat is 6,200 cc, and 707 bhp, making 8.76 cc per bhp, with a haybusa tune it would be 838 bhp

Meanwhile back in the real world her indoors drives an 02 1,300 cc kia rio that makes 96 bhp, it costs MORE to road tax every year than the 01 1,950 cc volvo diesel that I drive, yet both make similar (to within 5%) mpg if driven steadily, the difference being the 2 litre volvo doesn’t slow down on steep hills and has overtaking power, whereas the 1.3 litre rio struggles at bit.

hcci should make a 1300 cc petrol that can keep up with a 2000 cc diesel in those scenarios.. without having to either put the pedal to the metal or drop a cog.

that’s my 2c anyway

Any thoughts on HCCI gasoline engines?