Threadjack is a fact of life on internet forums these days, and in this case it seemed quite necessary. Why? To help stamp out Urban Legends that lead to false expectations. Said another way, if folks get to continually say stuff like, "Adding a CAI to your car will improve your fuel economy from 28 mpg to 34 mpg" without being challenged, other folks less in the know might start thinking that by simply adding a CAI kit to their car they too can realize an improvement in fuel economy of over 20%, and that is simply isn't true.

 

Well, theres always two sides to different products! Thats how I view it. The truth is that there isn't really proof to either side. The truth is that neither Shipo or I could state anything without our statements being rebuttled by the other.
So the conclusion to this all?
I guess you guys can decide who you think is right.

 

To Shipos post.

I don't have the energy to spend all this time replying to these posts.
Obviously you think that CAI's aren't good, and I think that they are a good improvement to cars. End of story. I don't think either of us can convince one another about whos right.

My final statements and thoughts.
35 miles per hour is where gas is used to its full potential. Anything lower, your not using the gas to its full potential. Anything higher, your using too much gas, and it can't all be used to its full potential. Thus, pushing on the throttle pedal too much makes it so your gas isn't being used to its full potential. Even if the computer calculates the fuel, air ratio. Chemisty and testing has proved this. I learned it in a chemitry class. Maybe you did too?

I believe that the cold air intakes provide the engine to breathe better. The colder air creates bigger explosions in your engine thus improving horsepower, torque and because there are larger explosions to less gas, better fuel economy.

The effects of the cold air intake does depend on the type of car it is on and the type of design for the cold air intake. For my mazda 3, it seems to work great!
Not only does it sound great but I can feel the difference in the car!

Shipo, no matter how much you may disagree, you have never had an intake in your mazda 3. Therefore, I have more to say then you. I have actually experienced the improvement on a mazda 3. You just have researched and yada yada.
It was nice debating this with you!
Cheers.

 

Sorry, have to comment on some of your, ummm, comments...

The thing is, if we don't engage in this debate (either here or a purpose built thread), then one of us will be going around with very bad and faulty information in our heads, and as such, we're going to be giving out bad advice. I know that if I'm wrong then I'd be awfully embarrassed to think of all of the bad advice I'd given out over the years when I figure out what the real truth is.

That may be true, but I doubt it. The RPM and load at which any given engine achieves its lowest rate of Brake Specific Fuel Consumption (BSFC) can vary dramatically, and given that gear ratios vary from model to model, I find it highly unlikely that it is a universal truth that peak fuel economy is acheved at 35 mph.

What did it prove to you? The fact is that modern engines that feature dynamic valve lift, duration, and timing, dynamic length intake manifolds, dynamic spark timing, and even psuedo-dynamic compression ratios, have a very broad RPM/Load range at which they can deliver power at or very near their lowest BSFC. Factor in aerodynamics and gear ratios and some cars will return their best fuel economy in the 40 mph range, while some will deliver peak mileage at speeds considerably higher than that.

At what throttle settings? I've never argued that they didn't offer nominally better breathing at peak RPM at WOT, but at anything less than that the "better breathing" argument becomes moot.

Ummm, no, from many perspectives. First off, colder air will allow an engine to develop more peak power, however, that only happens if the engine is supplied with more fuel to keep the air/fuel ratio in balance; and as the intake charge continues to get even colder (say below 40 degrees), the engine management system needs to make the mixture even richer as atomization efficiency declines with the temperature of the charge. So, while an engine running in ambient air of say 20 degrees will definitely develop more power than that same engine on a 100 degree day; every unit of power from the engine running in the colder environment will require more fuel.

As for larger explosions, there really shouldn't be any such thing in our engines. Said another way, if the intake charge is "exploding" in your engine, then detonation is occurring and your engine isn't long for the world. What should actually be happening following the spark event is the intake charge burns in the form of a wave front that goes "whoosh" across the combustion chamber. The more homogenous a fuel charge is, the smoother the burn and the better the fuel economy.

At wide open throttle and near red-line, I believe you, below that I'm skeptical.

So what about the three questions I asked you in my last post? Quite honestly I think this would serve both of us and the membership here as well to bring this discussion to a conclusion.

FWIW, so as to place this discussion where it belongs, I’ve created a new thread called "CAIs and Fuel Economy; what's the real truth?” over here:

https://www.mazdaforum.com/forum/general-tech-6/cais-fuel-economy%3B-whats-real-truth-20812/

I encourage you to join in the discussion as neither of us will learn anything unless you do.