Does CAI improve mileage on an otherwise stock XLT

[2TimingTom]

On my Mazda Protege, I used everything from the stock intake to a CAI that had the filter sitting outside the engine bay in front of the front wheel and behind the fog light. I even had a header, high flow cat and cat-back exhaust on it. I even removed a set of butterflies that sit in the intake manifold just before the cylinder head.

I started with a 100% stock car and modified the crap out of it and then sold most of the parts and put what I could back to stock. In that entire time, I never noticed any difference in mpgs that I would attribute to the breathing mods being there or not being there. It was a daily driver and I'd say my driving habits remained pretty consistant throughout. I did notice better response and acceleration with the breathing mods all in place.

It seems that the small, 4 cylinder motors are hard to gain any power from via simple bolt ons. I think the engineers extracted nearly as much as possible at the factory. With larger 6 and 8 cylinder motors (my 4.0 in my Explorer is twice the displacement of my 2.0 Protege motor yet only 52% more power (134 vs 205)) it seems that breathing mods are more effective.

So like I said before in reply #8, don't get any kind of bolt on mod strictly for "mpg savings". Get it either for power or bling or both.

 

[FIND]

^ That's why ^ people who want increased MPG create "warm air" intakes... That does work...

Thank god you were here to save this thread and insert some reason.

 

[Fifty150]

instead of sucking in cold air from the fender (like the stock intake box) it pulls in warm air from the engine bay

I monitor my intake air temperature with a laptop computer hooked up to the car's OBD II port, or a ScanGauge II. You only get "cold air" when you're moving and there is decent airflow. At highway speeds, with an ambient temperature of 60 degrees, my intake air temperature runs from 70 - 75. When I had the factory air box, intake temps were always from 120 - 150. In my car, the air intake tube runs right next to the upper radiator line. In stop & go traffic, the radiator line heats up the air in the intake tube, giving me the same exact conditions as the factory air box.

 

[Phil111260]

so are you better off just getting a performance filter?

 

[celly]

I monitor my intake air temperature with a laptop computer hooked up to the car's OBD II port, or a ScanGauge II. You only get "cold air" when you're moving and there is decent airflow. At highway speeds, with an ambient temperature of 60 degrees, my intake air temperature runs from 70 - 75. When I had the factory air box, intake temps were always from 120 - 150. In my car, the air intake tube runs right next to the upper radiator line. In stop & go traffic, the radiator line heats up the air in the intake tube, giving me the same exact conditions as the factory air box.

That's pretty much what I see with mine as well (I use a SG as well). Actually, it's pretty cold out today and my intake air temps were around 17F-19F (pretty close to outdoor temps) and that was in city traffic. Do I notice any performance gains in cold weather? Not really. The whole "hot air vs cold air" argument is based on theory, but I've never noticed much. My truck tends to run better in summer, but I think that's because it's never much cared for winter gas.

I do like air intake setups because I do feel they're less restrictive. I noticed marginal gains when I put one on mine (and the Explorer Sport before it). Very subtle change. Improved throttle response and sounds more aggressive. Nowhere near the bold claims the manufacturers make, but something there. That's why I tend to recommend that people make their own setups. There is a definite price premium on those "store bought" units a la MAC, K&N and Volant.

I discussed these basic mods with a trusted colleague a while back and he feels that the only way you'll see benefit from an air intake setup is to also free up your exhaust. If it inhales better, it also needs to exhale. I noticed a boost in performance when I put the new exhaust maybe a day or two after installing the air intake on my 5.0 (I had a similar setup on my old SOHC 4.0 Sport as well). I feel the exhaust gave me a bigger boost than the air intake.

You really notice the benefits of the mods when you tie them together with custom tunes a la SCT. It really feel these three mods (air intake, exhaust and custom tuning) work well together. Whether one can justify the cost of all three is a matter of debate. In my case, I was underwhelmed by the 5.0 in stock form when I first test drove it. I had been driving the SOHC with similar mods for a few years and the V8 seemed pretty dull until I went with the same three mods within weeks of getting the 5.0.

I use a Volant based setup so my filter is housed in a box not unlike the stock one, albeit way more breathing room. I truly don't feel a "performance filter" (in stock box) will make a difference over a basic filter because it's still scrunched up in the stock airbox. I do know of someone who has dyno tested a Volant air intake on another truck (SOHC I think) and did say there were small gains of around 2-3 HP if I recall. I'd have to dig out emails from about 5-6 years ago to get the real #'s. He said he got similar #'s from exhaust. I don't remember his what setup he was testing it on either.

At the end of the day, the best "mileage mod" is your right foot and the imaginary "egg" under your foot. Al Franklin (aldive) always said just that. One of the readings I like to measure on my Scangauge is the throttle position sensor. Keep it as low as possible and your mileage improves big time. A lot of mileage weenies out there on the web swear by the Scangauge for that very reason.

My problem is I like to drive aggressively and the basic mods I've done (air intake, exhaust, headers, UI spacer and tuning) makes my truck way more fun to drive than a stock one. I love how it sounds too. I'm not into super loud exhaust, but when I stomp on it, it sounds pretty mean.

We can debate this until we're blue in the face (in many ways it's a tired argument and gets repeated often).

Do what works best for YOU.

 

[Fifty150]

so are you better off just getting a performance filter?

Yes & no. A performance filter may offer a little better flow than the stock filter. However, it is still in the factory air box. You will still be running with under hood temps of 120+. The advantage of the cold air intake is, obviously, cold air. You will get cold air when you need it most; while accelerating rapidly & at freeway speeds.

What I do notice is that in my other car, a Ford F-150, the upper radiator hose runs towards the passenger side just like in my Ford Explorer, but the intake goes towards the driver side as opposed to running to the passenger side fender. In the F-150, I don't have hot coolant heating up the airway passage, so the air is a lot cooler, even while in stop & go traffic. With the F-150, I can see inatake air temps near ambient at freeway speeds.

Look inside your stock air box. Now look at the paper filter. Where the air comes in from the fender, you should see on the filter a dark patch of dirt. It is roughly about an inch wide, and perhaps 4 inches long. That is all the air that you will get. And if you don't look in there at all, ever, then you have never rotated that paper to get the clean part of the paper in front of the air inlet. I have opened up air boxes to find that the little space that is actually filtering air was completely blocked by dirt, and the rest of the filter was perfectly clean.

If you simply vacuum the dirt off of that one area, and rotate the paper filter every oil change (5,000 miles), you could easily run that $15 paper filter for 40,000 miles. I wouldn't recommend it, but you can get away with it. My dad was famous for pinching pennies that way. He would use the crevice attachment with the brush on the end, and "clean" the paper air filter at every oil change interval. With oiled filters, you could easily clean & re-use that same filter for the lifetime of that vehicle. The manufacturers say that oiled filters are good for up to 50,000 between cleanings, and that you can accumulate up to 1/8th of an inch worth of dirt before it needs cleaning. In fact, K&N claims that you can wash and re-use their filter up to 100 times, and has a million mile warranty.