Hello
 

Hello,

Hypermiling attempts with an '07 Civic Si sedan.

Paradoxically, I want great performance, but only if mileage can be improved day-to-day. Hard to beat this platform; great for the track (though not as zippy as a Mini Cooper S), but unbeatable, naturally-aspirated Honda engine!
:)

well I think you will have to decide awesome mpg or fast street performer?

as gas reaches 6 dollars a gallon later this year maybe you will have something to think about.

I mean I love sports cars but I think their time has passed :(

iomatic -

Welcome to EM! I keep thinking that you have the whole tuner crowd to fall back on with your Civic SI. If I were you, I would try to establish a "baseline granny" MPG to know where you stand. What is your current MPG? I assume you have a manual transmission.

CarloSW2

Sweet ride! Gotta love the build on that engine...

Welcome to EM! I think you should be able to eke out some pretty good day-to-day.

Welcome to the site. I'd agree with SVOboy, you can still get some really good mileage (40+ fairly easy) out of that that car.

@digitaldissent: I understand what you're saying, but some performance mods actually are more fuel-efficient. For example, in most cases, a race header (with a high-flow cat--no super-pollution for me either.) increases exhaust throughput and power, while not burning up more gas. Lighter wheels (unsprung weight) and shifting weight off the drivetrain increases performance by taking hindrances off the engine.

So, some of these mods are actually beneficial for mileage and performance; they are not mutually exclusive.

I should clarify that I'm not here to reduce my total carbon offset that I'm raising my own vegetables by rotating crops and outfitting used solar panels all over my roof...:) I do what I can, but I will still race my car on weekends, and drive like a granny on the weekdays (though I doubt many grannies hypermile and slipstream behind trucks 5-10 feet behind at >55 MPH, cruising in at highway speeds at neutral on off-ramps, and taking turns at speed).

Another great advantage of having a sports-oriented vehicle--though safe driving of course is the best choice--is that you can indeed eke out more mileage by having a perfomance-based vehicle with track capabilities to use perpetualized acceleration (e.g., coming off ramps), quick braking, coasting in neutral, and taking turns without fear at (hopefully reasonable ;)) speeds.

My thoughts are that a track-capable vehicle is safer in that regard (being able to use tight suspension, good tire grip, and driver skill), to pull off some of the more extreme hypermiling stunts (to a lesser, more safer degree).

where you will really make milage gains is to hook up some hondata Kpro and endlessly tweak the cruising and low rpm and throttle opening ranges, seeing how little fuel or how little(or negative) cam angles and such that you can get. the fun part is since you are running vtec vtc you can have a real sipper (beyond how the factor sets it, possibly run wicked low or neg cam angles to have a slight atkinson effect) when not getting on it fully, then when your throttle goes past wherever you set it at, you can eek more power than current out of it. I'm looking someday to add this to mine (though I have the K20a3 instead of the K20Z3 so I'm down 50 horse and a some RPMs from you, I can essentially turn off an intake port per cyl)