Both RL and TL should go RWD if they want to grow any larger.

 

The C&D article helped explain it a lot.

However, HCCI still doesn't sound like anything worth pursuing. Unless Honda has found a breakthrough to this, the difficulty of running a HCCI engine, along with having to "hybrid" it with Internal Combustion components when the car isn't running lean, and then pairing this system up to an electric motor just seems overly complex.

Also, since octane is a measure of resistance to combustion under pressure, which seems to fly in the face of what HCCI tries to do, would a HCCI engine perform better on lower octane gas?

Hey, and thanks for explaining this guys.

 

i'm not sure what you mean by "hybrid it with internal combustion components." this is still an internal combustion engine, for one thing, and what components would you have to "hybrid it" with? assuming they get the engine production ready, there's no reason why they can't pair it up with an electric motor for a hybrid setup. the way the fuel ignites is of no consequence to how the electric motor is engaged.

i doubt that anyone would make an announcement like this if they weren't confident that they could bring it to market. it's pretty clear that they're already pursuing this technology, as they're almost ready to demonstrate a prototype engine in action to journalists. it sounds like the project is pretty far along. as for octane limitations, if honda produces this engine, i'm sure they'll think about that first.

 

This is great news IMO.

HCCI, should it come to market will have a dramatic effect on Honda's CAFE rating. And a potential shift to rear-wheel drive is music to my ears. :love:

 

Well, just reading the C&D article, it sounds like HCCI would run too lean in a variety of driving applications that it would require standard gas engine components anyway.

 

what "standard gas engine components" are you talking about??

 

The engine in my lab runs on a standard Ford 2.2L four cylinder block with high compression pistons on an ECOTEC head. We use anything from pure iso-octane to regular gas as fuel. The idea is that it isn't that different from normal gas engines.

 

Here's the bit from C&D that's causing the confusion:

 

i see what you're getting at finally. i guess we'll just have to wait and see what they come up with.

 

After reading the C&D article snippet I think I can offer a decent explanation.

Essentially you would need an engine that is able to operate in two combustion modes: HCCI and "regular." During low-load driving the engine runs in HCCI mode which has very low fuel consumption. When extra power is needed the engine kicks over to regular combustion mode. Overall, the engine uses less gas because it is only running in regular combustion mode when the driver requests extra power, and the rest of the time it's in HCCI.

Think of it like the SpeedStep technology that was used in some of Intel's mobile processors. When on battery power, the processor would have a low baseline clock speed for basic operations, and then when the user started to do something that required more computing power the processor would ramp up to a higher clock speed to get that work done more quickly. So instead of always running at that higher clock speed (i.e. normal combustion on the HCCI engine) all the time, it is able to run at that lower clock speed (HCCI combustion) when the extra grunt isn't needed.

Make sense?