There's no replacement for dusplacement

[strat61caster]

Originally Posted by ZDan

Whatchoo talking about here? *IF* the S2000 were making "more use of its fuel for power", that goes against your premise that it gets worse fuel economy. But then since it *doesn't* get worse fuel economy, your kinda right here, but your reasoning makey no sense (to me).

I'll figure the math later tonight, basically we're comparing WOT vs. cruising speed. Basically I'll pull the horsepower figures at whatever RPM make an estimate on efficiency and compare how much power/fuel each car uses at peak output. Chevy put more development into reducing fuel consumption during steady state cruising (cylinder shutoff, timing and ECU changes) utilizing the gobs of torque a large displacement motor has to maintain driveability whereas Honda with the help of Vtec angled to a more performance oriented tune with good driveability down low to compensate for the lack of torque sacrificing a bit of fuel economy.

I'll concede on the S2k C6 real world fuel economy comparison, I never really cared to look into it too much but the fact remains that they get remarkably similar gas mileage out of a lighter 2.2L compared to a heavier 6L.

[rice_classic]

Other than cruising, the S2k has the Vette beat in efficiency hands down. Rush hour traffic, city driving, grocery store trips and even spirited driving. S2k wins.

Open freeway @ 75mph in top gear with no traffic for 200 miles?.. eh, now the vette wins, however that's not accounting for variables such as gear ratios and aero allow the vette to 'punch above its weight' in terms of efficiency on the freeway. Plus, isn't "cylinder deactivation" the same thing as reducing displacement, just in a dynamic fashion.

Cylinder deactivation is to efficiency as VTEC is to power. A dynamic method of making 1 engine design function like 2 separate ones.

Atropine brought up Rotary. Rotary was an example of less displacement and less efficiency. Compare the MPG's of the S2k now against an RX8. Exactly.
"So let me get this straight, this thing only has 1.5L of displacement, makes the power of 2.5L piston engine but has the efficiency of a Ford Econoline?.. And who the hell thought that was a good idea?"

[ZDan]

Originally Posted by OrbitalEllipses

Horrifically small sample size is horrifically small...

That's why I included that info, I wasn't going to throw it out there as gospel since it's such a small sample. But still, *initial* results are right where the C6 left off, we'll see where they go from there.

[OrbitalEllipses]

Originally Posted by ZDan

That's why I included that info, I wasn't going to throw it out there as gospel since it's such a small sample. But still, *initial* results are right where the C6 left off, we'll see where they go from there.

And if I was one of four people to put my C7 on fuelly...you bet your ass I'd be driving pedal to the metal.

[ZDan]

Originally Posted by OrbitalEllipses

And if I was one of four people to put my C7 on fuelly...you bet your ass I'd be driving pedal to the metal.

And if I was one of 'em, I would be trying to see how much mpg I could get on my commute. It's not like most of the people who buy these cars have never driven fast cars before...

Any case, that's why I threw that info out there, data is in short supply at the moment. I would expect the mpg to go up, but we shall see...

[Rayme]

Originally Posted by rice_classic

Other than cruising, the S2k has the Vette beat in efficiency hands down. Rush hour traffic, city driving, grocery store trips and even spirited driving. S2k wins.

Open freeway @ 75mph in top gear with no traffic for 200 miles?.. eh, now the vette wins, however that's not accounting for variables such as gear ratios and aero allow the vette to 'punch above its weight' in terms of efficiency on the freeway. Plus, isn't "cylinder deactivation" the same thing as reducing displacement, just in a dynamic fashion.

Cylinder deactivation is to efficiency as VTEC is to power. A dynamic method of making 1 engine design function like 2 separate ones.

Atropine brought up Rotary. Rotary was an example of less displacement and less efficiency. Compare the MPG's of the S2k now against an RX8. Exactly.
"So let me get this straight, this thing only has 1.5L of displacement, makes the power of 2.5L piston engine but has the efficiency of a Ford Econoline?.. And who the hell thought that was a good idea?"

the only good "efficiency" the s2000 is for is power per liter. It sucks at torque and fuel economy (for a puny 2.0). Why brag about it's efficiency when you have to live with shitty mpg and torque? I'm completely understand the point of the engine, it's fun and it's an amazing car but at the end of the day it's just a written specs.

[Levi]

Originally Posted by Rayme

the only good "efficiency" the s2000 is for is power per liter. It sucks at torque and fuel economy (for a puny 2.0). Why brag about it's efficiency when you have to live with shitty mpg and torque? I'm completely understand the point of the engine, it's fun and it's an amazing car but at the end of the day it's just a written specs.

Not everbody want efficiency, especially for a week-end/track toy.

[rice_classic]

Originally Posted by Rayme

the only good "efficiency" the s2000 is for is power per liter. It sucks at torque and fuel economy (for a puny 2.0). Why brag about it's efficiency when you have to live with shitty mpg and torque? I'm completely understand the point of the engine, it's fun and it's an amazing car but at the end of the day it's just a written specs.

You. Point. Missed.

[Rayme]

Originally Posted by rice_classic

You. Point. Missed.

must be because you use the word efficiency as a synonym to mpg and what it seems to be everyday driving..what do you mean by efficiency???

When talking about efficiency and engine and displacement..like in this thread it is usually a short term for volumetric efficiency.

[serialk11r]

The F20C is a very efficient engine with some racing pretensions attached to a gearbox much better suited for the track than the road, so its mpg sucks. The LS engines are attached to a gearbox more suited for a tractor than a performance car, but the engine has so much power no one is complaining. Heh.

Also BSFC at WOT is probably lower for the LSx because it's got such a big bore (=less thermal losses), but since you don't get to use the power on the street as much the mpg ends up worse typically.

[serialk11r]

Originally Posted by Dimman

Mazda solved the rotary issues when they stopped making it.

Heh...

Plus the only thing limiting large displacement engine under boost is common sense and drivetrain strength.

If I had a rotary engine powered car, I would be more concerned about engine replacement and premix + replenishing oil cost than gasoline lol. Gas mileage is the least of that engine's problems.

There's nothing limiting large displacement engines from boost, that's called a "hypercar". I guess that's synonymous with "lack of common sense".

[rice_classic]

Originally Posted by Rayme

must be because you use the word efficiency as a synonym to mpg and what it seems to be everyday driving..what do you mean by efficiency???

When talking about efficiency and engine and displacement..like in this thread it is usually a short term for volumetric efficiency.

A word can have more than one meaning if you consider context. My original post did say "efficiency", true, but the conversation from there by Zdan and Strat involved the S2k and was about fuel efficiency.

So I was wrong about you missing the point, you were actually just missing the context.

[strat61caster]

My janky back of the envelope calculations are delivard:

https://docs.google.com/spreadsheets...it?usp=sharing

[hmong337]

I win!

1.5L V6 twin turbo 1000hp