Who wants 2-3 mpg better

[NHarris]

Stock. You got aftermarket headers?
looks like different heat wrap than what we were talking about.

 

[jd4242]

Yea there aftermarket headers.ooo heat wrap tape,yea don't ever do that.

 

[zjrog]

I know it goes against the grain, but warm air will get you better mileage than cold air. Cold air is great for power. Chances are, you might actually have changed your driving habits ever so slightly, and that is where you see the change...

 

[rileyrs]

I know it goes against the grain, but warm air will get you better mileage than cold air. Cold air is great for power. Chances are, you might actually have changed your driving habits ever so slightly, and that is where you see the change...

Wrong. Cooler air is more dense (basic chemistry), which means there's more oxygen, and oxygen is what fuel needs to burn. More oxygen equals more efficient burn. More efficient burn, equals better fuel mileage AND power.

 

[kelvin37]

thank you for clarifying that for him, because if he wants i can video all of my findings just to show him that i am not making this stuff up. and that i did not change my driving habits. the way i know that is that my wife still holds on the door like i am going out of the atmosphere. some how i can get great gas mileage while driving like a ****** bag, and she can never get above 21mpg.

 

[zjrog]

I know some of the basic chemistry. But I also follow some of the fuel efficiency forums as well. I'm not doubting you see an increase. But the folks on the eco forums will be happy to show you 5-10 MPG improvement during the summer months.

Now for my own experiences. 1995 Grand Cherokee 4.0. I can 22MPG with it in the summer time, easy. But in winter, my MPGs fall to 18. Still better than EPA though. This summer, I changed a few things and am still firmly in the 18s.

 

[storlied]

He's right, better fuel economy comes from warm air rather than cold.. but yes.. you will see better MPG with cooler air if it's helping the combustion process in your specific situation.. might have a lil more power also. We're all in different climates, at different elevations..ect.. our vehicles are unique in their own ways, how they run, what issues they have..ect.. Gotta keep all that for consideration.

Colder air either way is gonna do just as he mentioned before.. it'll be more dense and the whole process will be more efficient to an extent.. with performance in a lot of cases comes MPG. I don't think it's so much about the driving habit change... you did this, but aren't rallyin around to notice any type of performance difference... rather doing this mod and driving like you usually do..

 

[damarble]

Don't forget, there's a lot of factors that contribute to lower winter mileage. For example, you drive differently based on weather, and winter fuel blends often have additives that reduce economy.

 

[storlied]

Additives? You mean all the water these companies love to water down their fuel with? That or, the low grade crap they send out?

That and the engine .. you warm your truck up, it idles higher to warm up faster...ect these things also will affect.

 

[damarble]

Additives? You mean all the water these companies love to water down their fuel with? That or, the low grade crap they send out?

That and the engine .. you warm your truck up, it idles higher to warm up faster...ect these things also will affect.

I've heard as much as 1/3 of every gallon is junk that won't burn. Anybody else know anything about that? It's that kinda BS that drove me to a diesel conversion. Pump diesel is pretty crappy now too, but at least I can make my own and bypass these scammers.

 

[storlied]

You can also use the heating diesel which is better for the engine and gains power but is illegal for street use. Apparently there is a die in it now so certain officials can see if you've been running it.

There's lots of companies all over the place that do something to their gas so they're making profit off of not as much actual fuel sold.......... pretty lame if you ask me.

Looking at the fuel report for the past month I've noticed a consistant H20 level in the 'super' (90 octane, our highest) fuel while 87, mid grade and diesel have none. [I worked at a gas station] Also, two big cab companies here have been advised Not to use Fuel from holiday as they report damage to fuel pumps while on this gas. [I've also noticed my engine runs like **** and pings while on Holiday gas... I have a 90 octane tune so things like this are a lot more obvious to me than others]

In other words, our world is going to **** and people are getting greedy .. nothing is what it seems. Yet we gotta keep goin... we need fuel, they will continue to sell us crap. They make the bucks while the majority of the public doesn't notice anything.

 

[Riks93XLT]

I haven't seen anyone comment to what I have been referring to as factory ram air ao I took some pictures that can help explain.

The plastic comes up to the grill with a square box with holes that sux the cold air in and is protected from water entry from the top of hood. Anyone else have this setup?http://www.flickr.com/photos/broussard70769/?saved=1

 

[rileyrs]

I know some of the basic chemistry. But I also follow some of the fuel efficiency forums as well. I'm not doubting you see an increase. But the folks on the eco forums will be happy to show you 5-10 MPG improvement during the summer months.

Now for my own experiences. 1995 Grand Cherokee 4.0. I can 22MPG with it in the summer time, easy. But in winter, my MPGs fall to 18. Still better than EPA though. This summer, I changed a few things and am still firmly in the 18s.

the reason you see better mileage in summer is because your engine can warm up to operating temp faster, and use less fuel/ be more efficient.
your trans and diff fluids will be thinner sooner, and create much less drag.
and less fuel additives, like ethanol.
NOT because the air is warmer.

 

[NHarris]

the reason you see better mileage in summer is because your engine can warm up to operating temp faster, and use less fuel/ be more efficient.
your trans and diff fluids will be thinner sooner, and create much less drag.
and less fuel additives, like ethanol.
NOT because the air is warmer.

Exactly right on that..
Warming up the engine in the cold weather is one of the most gas guzzling times.

 

[alakers]

kelvin37, i posted something about new mods to my 94 for increasing mileage and cheap 4x4, this mod seems like a great idea and something im considering, you said you live in arizona, so i imagine your ex. never needs hot air to heat the engine, i live in wyoming, and take it to the mountains on ski trips often. would this keep my engine from heating itself correctly, making it less reliable in cold climate ?

 

[storlied]

Either way you do won't cause any harm or noticeable degrade in performance. Just whatever you do.. make sure the intake isn't gonna be vulnerable to getting water/junk into it or you'll be having trouble.

Some people have the stock config which pulls air from the fender or front header panel which is fine. Some people like me has a short ram intake, lets more air in.. but it's awfully hot in there.. I need to make an airbox. Ram air, real ram air isn't too practical up until you get to a really high speed, and having that type of system introduces a risk with rain and various other things. Most hot rodders will go running back to their garages first sign of rain because of their ram air, or whatever exotic setup they have.

I say go with a cold air intake, which in reality is just a short ram intake... you'll get more air with less restriction which is good, the only downfall if you don't have a heat shield or airbox around the filter is hot air, but it's not going to hurt anything.

 

[NHarris]

The cold air intake is better as said by storlied, there is less restriction. There is not heat shield, but some companies do sell a heat shield with their cold air intakes. Some intakes no matter what even the stock intakes will take heat from the engine. The setup I have on my 05 has a cold air intake leading straight in to the airbox with the airbox mod with K&N filter. It works well does the mpg's I want to get out of it.
So in all I agree with storlied cold air intake is a better way to go.

 

[kelvin37]

ever hear of a rad guage. Relative Air Density. It is used to set the fuel air ratio on race cars. If a motor takes in hot air it is like driving at high altitude. the colder the air the better. The standard lapse rate is roughly 3 degrees per thousand feet. so for every 3 degrees hotter air its like driving about a thousand ft. higher. Cool air is your best friend. Ir allows your mass a/f sensor to send more fuel to the engine, and thereby make more HP, which equals better fuel mileage at a lower butterfly valve angle.

 

[storlied]

I think we're starting to lean from the original topic, while a CAI is an improvement.. the OP is looking for a cheap way to improve the stock configuration for mileage. IMO there's only so far you can push things until you need to spend some cash on improved designs.. that can apply for anything really.

Another thing said can also be hotter air, being less dense will call for less fuel = fuel economy improvements. There was a thread on here by one of the more well known members about hot air and gas mileage.

 

[kelvin37]

One could argue that hot air will call for less fuel , this is true, but it will not result in increased fuel mileage. The hot air, we are talking about, 180 -200 degree coming off the radiator, heats the intake tract to roughly the same temp, the amount of air over the outside being so much greater than the internal flow. This is outside the range of the MAFS, so it results in a slightly rich weak mixture on the low side of the stoichoimetric ideal. Low air density also impedes volumetric efficiency as the engine wants as much air as it can get as freely as possible, resulting in better combustion chamber swirl.
if you want hot air, you need it really hot, about 450 or so, this is called a plasma induction system, Smokey Yunick developed it in the 70's, it used two turbos, lots of boost and was really efficient. and the metalurgy it needed was expensive. It it also needs direct injection otherwise you get an exothermic reaction ( detonation). Another problem caused by hot air intake tracts. So keep it cool and spend less on fuel.