Shipo,

you always seem to be very scientific and display the thought process of an engineer. I appreciate that. But as scientist one has to accept facts that one might not think are right if they make logical sense.

What I have showcased makes logical sense.

I am an engineer and I have worked with the software used on cars made by GM, Volvo and Mercedes-Benz; I've spent plenty of time analyzing the dynamometer results of any number of engine configurations including highly restrictive intakes, various factory intakes, aftermarket intakes and even no intake at all, and I can tell you with absolute certainty that modern OBD-II fuel injected engines will consume the same amount of fuel for any given amount of power, regardless of how the intake is configured from a restriction perspective. The only things which make a difference is the heat of the intake charge (the higher the heat the lower the maximum power available but the higher the fuel economy), and intake resonance.

From an engineering perspective, the items you've showcased really don't affect fuel economy.

As a side note, if, as potentially indicated by your avatar, you are a pilot and fly a plane which is carbureted; once you're up to cruising altitude on a day where the OAT at altitude is below freezing, try adding some carb heat and then leaning the mixture to a point just shy of causing the engine to run rough. If you do, you'll be amazed at how your GPH drops (typically by several GPH) with virtually no loss in cruising speed. Contrary to the "cold air makes more power" argument (which it will do with a commensurate increase in the richness of the air to fuel ratio), it is actually a warmer intake charge which allows the best fuel efficiency.

From an engineering perspective I guess you are right they"really don't affect" economy but they can and still do however marginal. From a practical perspective it still holds merit albiet a small amount.

As far as the plane (182) in my avatar, we were running a modified Lycoming TIO-540 turbocharged - fuel injected engine. But I can understand your statement about below freezing temps and the affect on a carbureted engine.

That is with a carb and now we are balancing efficiency with power. Of course more dense air will require more fuel for the propper mixture. So what we "loose" in initial economy we pick up in power which can increase economy due to the ability to get to speed faster. Which begs the question, where is the "crossover" point? In my opinion that is getting down to a point where we are splitting hairs

A TIO-360 in a 182? Yikes; never heard of such a beast. :) I'll bet when a new A&P looks under the cowling he or she does a double take when they see that four banger in there. :)

Where'd you get the STC for that engine swap?

Sorry I was thinkin of our old craft the 172, the 182 has the 540 haha. It would be a bit of a pig with a 360

Most of them are decently modified for a bump in power. It's in the best interest of the military haha

No STC needed (at least for an engine swap), I was just thinking of the wrong plane.

Ahhh, a 540, makes a heck of a lot more sense. :) That said, a 172 with a TIO-360 would be a pretty hot Skyhawk; mine had an O-300 (smooth but slow). :)

she was a screamer, but I really love the terrain tracking and traffic warnings of the g1000 in the 182, so much different than flying from the six pack.

I think the 172 started with an O300, then we got it had it overhauled and the TOI 360 swapped in, great little plane was a awesome climber, just no electronic aides. Not a bad thing just not great when you are searching and locate downed craft.

Sorry to hijack the thread.