Elmo P. Shagnasty wrote:
> In article <X6CdndVcWtBDRSPfRVn-3Q@speakeasy.net>,
> jim beam <nospam@example.net> wrote:
>
>
>>but formulations change between producer, by country, by state, by
>>season, by law, by mistake... there's plenty of reason to use smart
>>management, and a by-product of that is being able to run any grade gas
>>to best advantage.
>
>
> no, the *only* thing it has to do is prevent engine damage from knocking.

there's more to gas than octane rating.

>
> You don't program it to run any grade at that grade's best advantage.
> For example, where does that stop? Can I put avgas into my Hybrid and
> the programming will "take advantage" of that?

modern programs run each tank of gas according to each engine sensor's
output and how that complies with what the ecu knows it can do with it.
if its ability to read sensor results for avgas are within its
abilities to manage, then sure, it can run avgas to best advantage. if
it can't, it won't and i'm not trying to tell you i know how the thing
is programmed.

>
> It's designed to run at 86 octane. Yes, the engine management computer
> will prevent damage should lower octane fuel be present, but that's
> different from saying it will change the engine parameters for more
> performance if higher octane is present.
>
> It doesn't do that.
>

i'm not interested in a personal disagreement - i'm only interested in
the technology. i've stated what what i understand to be the current
state of the art, and that /does/ include ability to run different
grades of gas to best advantage. i'm /assuming/ this applies to the
honda because honda have the necessary sensors, ie. knock and crankshaft
angular velocity, [among others]. and they have a good mechanical
design. other than fuel/air charge & ignition, one other big thing in
the performance equation is combustion chamber design. basically, some
designs can only run well with high octane. honda otoh have a design
that fundamentally runs well with lower octanes, but burns higher
octanes very well too - something that's hard to do well the other way
around. from that perspective, the honda /should/ be able to take best
advantage of different grades if it's getting the necessary ecu input
and has sufficient "smarts" to handle it, hence my assumption.

but maybe you /know/ this is not the case.