Cold air still takes more fuel to burn. Warm air is less dense and takes less fuel to burn. Which is better for mpg's? Why do most vehicles get better mpg's during the summer months. Sorry, you won't convince me that my mpg increase and better throttle response is imaginary. Lol If you want power, cold air ram intake by far. If you want mpg's, warm air works best with as free flowing design as possible. I'd still run warm air and an oval filter though. As soon as I find the right filter, my 5.o will get the same treatment. I've eliminated the cold air tube and gained about 1.5 + 2 mpg on it with warm air. I despise the air intake drone though at higher speeds. Sounds like a tornado under the hood on higher acceleration.

 

Warlockk,

Sounds like a well made up argument, manifold vacuum decreases at wot,the inet air velocity increases with rpm, place a vac gauge above the throttle plates and you wil see it rise as mani vac falls. I m not buying the ford tuned ram tube idea, i think its just there to make the airbox a on fits all, and the air box duct is more about cabin noise than power gains, the high pressure area behind the grille is likely compromised by the air being pulled by the cooling fan. Dont know about t 4.9 but the ducting on my 1992 50 has an opening smaller than my 1989 4.9, but placed higher, probably because of the duct sucking water ,snow and other crap on the early trucks. Thats why i move my intake up and back as far as i could.

 

everyone is about 50% right, put the facts together and you are all right

cold air=better power
warm air=better MPG

i kept my stock air boxes on my f150, f250 and ram 1500. i just bought the flat replacement filter. i noticed better throttle response in all trucks. im not after MPG anymore so i have no reason to hack up my air box or remove it completely, but having a warm air intake is suppose to get better MPG aslong as air can get into the engine bay.

with the new f150 i will be trying for better MPG because it will be my cruiser.

 

I wonder how much nitrous i could hose down this thing before it farts parts.

 

around a 200 shot lol.

 

I'm not sure I'm following you on the pressure area behind the grill. On all the factory intakes I've seen the inlet tube goes through the radiator mount next to the radiator or over the top of the radiator mount. It's located just behind the decorative grill where all the air hits the radiator,a/v cooler oil cooler etc. At speed air is forced through the grill and through any openings ( radiator and intake ) at high speed and pressure. That's why we use clutch fans and electric fans. At driving speed the pressure and flow is adequate without a fan. As for summer Mpg I know it was posted before, but if you have it available can you post the link to the higher mileage in summer data. Otherwise ill try to search for it. It doesn't seem to make sense to me. Here are a few things I'm pondering. 1)We have generally been saying that of you make more power, then you will use the throttle less. So this point seems to go against that. 2) Summer fuel in most of the country is oxygenated to increase warm weather performance and decrease emissions. Without seeing the data, this may account for some of the discrepancy. 3) there is a war going on with auto manufacturers for the best mpg. While I worked there Toyota spent millions to change their entire line to synthetic oil because they gained 1-4 mpg on their vehicles. If warm air actually produced more mpg wouldn't they use an engine bay intake on every vehicle? Especially considering that it would require less material? However just the opposite is true. Every new vehicle I can think of at the moment, especially high mpg models like the prius and the focus use cold air intakes. 4) Ignoring the Maf for a moment, which does uses temperature differential to measure air intake and reads intake temp. Most of our trucks use intake pressure to measure air intake and an O2 sensor to decide how much fuel to add after it is burned. How would the system know the air cold and raise fuel output. 5) Egr uses burned exhust gas at hundreds of degrees to lower cylinder temp to increase fuel efficiency. Meaning the cylinder is hot, so anything to cool that cylinder would be helpful. 6) I believe we have stated before, running a lower thermostat to keep the engine cooler also increases Mpg. Unless I have that backward that seems to support my cooler air cooler cylinder better burn theory. I am open for discussion on all of these. That's how we get the most out of our vehicles.

 

I would agree with you, there is an aspect we are missing here, either scientific and/or computer combinations. Drag racers back in the 1960's used to ice down, literally with ICE, ..... Ice down their intakes before the race to make them as cold as possible, so when the air entered the engine it was more dense. Now today with computers and fuel injection maybe the cold air theory is out the window, but I have always been under the impression that cold air = more power. Not sure on the mpg. If you look back in history, most cars had a metal tube off the air cleaner that sat on top of the carb... doesnt get much warmer than that.. but then on the higher performance models, say Plymouth Roadrunner, you could get an "air grabber hood" where a hood scoop would actually come up out of the hood to get outside air.

 

I simply googled Warm Air Intake Fuel Economy and found tons of posts, and arguments. Lot's and lots of warm air MPG gains reported. Mostlt in small cars, but there is a following of fuel savers on the Tundra web sites. Ecomodder.com has allot of warm air intake test results as well. I decided to try it and it works very well for me. We're at 3.80@gallon this morning at my regular gas station. I'm rarely hauling heavy loads right now and my driving consists of mainly interstate driving of some 40 miles one way to work. My best mpg showing was 21mpg at 60mph with a few red lights on a 100 mile trip to work on country highways. I'm back working closer to home and getting 20mpg on the interstate at at 70 mph. Wish I had the money to blow and do a mpg test on the old 100 mile route to work at 60mph. I'm guessing I could average 23mpg now that I've done the timing bump. If I'm having a teenage day, I can still boast some roasted tires and 10mpg with the windows down and the radio blaring while enjoying a cool 70 degree morning air. I was talking to my ex last night and trying to remember when we got the 95 I'm talking about. Seems like it was later in '97 or early '98. I've really dogged this truck and let the maintenance go until recently. It's a miracle that this 4.9l is still running. So as long as I stay away from that 40 year old teenager urge, I'll be looking for more fuel efficiency. One thing I've thought about is installing an intake tube directly into the grill with a push/pull cable and door so that when the air temps get over 100 this summer, I could experiment with air temps and really test the sweet spot for intake temps. I have a old thermometer somewhere around here with a probe for outside temps that I want to mount in the tube right in front of the tb to see just what the air temp is and maybe play around with my setup.

 

What about the "breather tube". Where do I put/place/pug that?

 

Replace it with a push in valve cover breather filter. There's a hundred different designs and colors and styles. I went with the $6 chrome valve cover breather filter from Autozone. When it gets dirty, I'm going with the washable breather filter style. If your going with the rf1012 K&N, cap the breather tube hole with a coke bottle cap of your favorite color and silicon.