Better Gas Mileage from my 06 Matrix

[thevisionseeker]

I'm new to this forum and am looking to find ways of increasing my gas mileage for my 06 Matrix.
I wrote on Matrixowners.com and someone sent me here but I'm having some issues finding things. Can anyone help?
I'm looking to help mileage during summer time and in the future winter time.
Thanks

[Daox]

That someone would be me. Welcome to ecomodder.

The Matrix is a pretty good platform for mileage. I've easily been able to achieve a steady 40+ mpg now that its warmer out. If I was the only one driving it I bet 45 wouldn't be too much trouble, but me and the wife both drive the car.

The first thing to check out is driving technique. It not only will provide you with your largest gain in mileage, but its by far the cheapest too! Our list of 100+ ecodriving tips is a great place to pickup some new info. We also have a thread for ecomodding for beginners which outlines some things you can do as well as modifications you can look into. The first mod I'd look into is pumping your tires up to maximum sidewall pressure. It reduces rolling resistance and increases the life of your tire.

You can also check out the link to my build thread in my signature for some ideas. There are also a few other Matrix/Vibe owners doing some good stuff here too.

[thevisionseeker]

Man you are quick! haha thanks!
I have read your post on putting a belly plate under the matrix but I'm worried about that. 1 concern is heat being trapped. 2 Moisture and what not getting trapped in as well. 3. Taking it on and off when you need to work on something underneath.
Its a cool idea just wonder how much it really helps. Not saying you are wrong by any means just my concerns.

I recently just got my car back from the shop because I hydroplanned into a cement median on the highway so I went and got new tires the other day. I make sure those are inflatted to the max all the time. I also drive a manual so I am usually thinking of how to save gas while I'm driving. I do the basic technics (cruise control, filling up when its cool out, not filling all the way to make sure fumes do not escape, etc...)

I would love to get 40+.
One thing I have thought about is getting a cold air intake or a short ram because I figured during the summer you want to cool down the motor correct and I dont race anymore so adding that would help cool down the motor. Correct?

[koihoshi]

Technically, filling up when it's cool out doesn't help much. Your gas comes from an underground tank.

Remember that gasoline is stored underground. Many feet below our wonderfully crusty earthy surface it's cold down there. Ever dug a hole in nice moist underground? It's cold about 1ft down, imagine how cold it is 15-20ft down where they hold the tanks. The only temperature difference would be your car, so you really aren't gaining much of anything. If that were the case the oil companies would be upping their prices by $.20 every night and putting it back down $.20 every afternoon saying it's an "Afternoon special!".

The tires being inflated at max will help you the most.

His underbelly pan (i was reading up on it) doesn't appear to be /air tight/, simply screwed into good spots. If you're that worried, drill a few tiny holes 1 or 2 so it doesn't stay (moisture/water). If you're worried about dirt and mud, etc, take it off once in a while. It appears his belly pan is held in by about 5-6 different bolts/screws, so taking it off to work on it underneath would not be too much of a hassle.

Be careful about your intake. Short ram if it's TOO short can sometimes just draw hot air straight into your intake, you make less power, it's less efficient (i say sometimes, not all cars are the same). And some setups and ECU's will compensate and sometimes cause the vehicle to run more richly (this varies from ECU to ECU).

Remember it isn't necessarily all about how much power you can make, but rather how efficient you can make what you have

[thevisionseeker]

See now I'm confused because I was just reading something on this site where it said having more air flow will make the ECU add more gas. This I understand but then I read that having warmer air actually helps the acceleration more. See I come from a racing side of things. For us it was the cooler the air the cooler the motor, the faster we go so when I was thinking about all this stuff I was thinking that adding a CAI or a Short Ram would allow colder air but I wouldnt be driving like I used to and in turn it would allow me to gain more mpg. But from what I just read that would not be the case.

[thevisionseeker]

How would adding a underbelly pan help? Less air resistance under the vehicle? Is that that much of a difference? I mean cuz if it is I'll go out tonight and to it! haha

I mean I am paying almost $50 to fill up every 2 weeks which every person at my work is given me crap about because I complain that that's too much haha. Except for that guy with the prius!

[koihoshi]

Originally Posted by thevisionseeker

See now I'm confused because I was just reading something on this site where it said having more air flow will make the ECU add more gas. This I understand but then I read that having warmer air actually helps the acceleration more. See I come from a racing side of things. For us it was the cooler the air the cooler the motor, the faster we go so when I was thinking about all this stuff I was thinking that adding a CAI or a Short Ram would allow colder air but I wouldnt be driving like I used to and in turn it would allow me to gain more mpg. But from what I just read that would not be the case.

I do too. We don't all come from ecomodding backgrounds, ya know.

Colder air makes more power with compression, period. Colder air contains MORE oxygen than hot air, it's condensed. Therefore cold air intake creates more power because most setups are pulling colder air from a fenderwell or in an area where the air is not hot.

And what I told you is exactly correct, rich = more gas added. Adding more air makes the ecu add more gas. Some think it's going faster than it really is and it richens up the mixture, but sometimes it causes it to run significantly richer. This varies from ECU to ECU and it is designed. But what I'm getting at is that just because you add an intake that adds more power doesn't mean you are going to get more miles per gallon.

So think of it this way... if your stock intake runs great and is more efficient for your ecu why change it? You may actually end up losing mileage if you go with a cold air intake or ram air. generally a short ram/ram intake is pulling hot air from the engine bay and improves power yes, BUT CAI is more effective for power because you're getting colder more condensed air that will make more power into the engine for compression.

But we're talking miles per gallon efficiency, not power efficiency.

-----

Back to an ecomodding perspective.

The underbelly pan reduces drag from components UNDER the car, making the air flow smoother. That's known as co-efficient of drag. The lower the co-efficient of drag, the less resistance there is, the less the car has to work and push itself to maintain speed/accelerate, etc.

If you want a cool example of this look up the early Lamborghini Diablos. They had the underbody of the entire car "smooth" with an underbelly pan setup. Very cool as an example, less drag.

On daily driver cars if you can decrease this on them you can pull more efficiency out of it on the highway which will increase your miles per gallon as well. The car is quite literally not "fighting" the wind as hard to push itself to maintain speed.

Ever put your hand out the window at highway speed? Stick it flat it's like a brake, tilt it like a "bird wing" and it's fine right? Same thing, if you can stop oddball un-aerodynamic disruptions in the car body, underneath it, anything that "catches" that airflow there is less resistance, you "cut" through the wind better at speed.

Wheel covers for example, smoother wheels, there is less air resistance as it isn't beating on your spokes and is simply "flowing" over a smooth surface.

[thevisionseeker]

haha naw I wasnt saying that. Didnt mean to insult.
Ok so pretty much I need to get off the power efficiency horse and find myself mpg efficiency horse. Ok so really going to a CAI or even a Short Ram wouldlnt do much but add more power? Depending on the ECU ofcourse but I think I understand what your saying.
Any suggestions?

Thats pretty much what I thought on the underbelly pan. It's a good idea I'm just wondering what material to use that will last and not cause any damage.
I think the material Daox used should work just Always worried abotu my car. haha

[koihoshi]

It's cool, I didn't take any offense, and I meant none as well. I'm hard to piss off either way :P

And correct. Remember that you could have a car with 300hp, drive it with the lightest foot possible, but you may get your butt handed to you by a little car that makes no power that runs /more/ efficiently in terms of your mileage. Making the car work/run/function better than what it is now.

Think of it this way. If a car that is already running really well gets 35mpg and you see things you can improve on (less weight, better aerodynamics and excellent driving habits) then you don't /need/ the extra power you're letting the car better utilize the power and efficiency it already has and "unleashing" the potential in it in daily driving in doing more with what you have. Not sure if you've read the big list of things yet. But it's excellent. You can find that Here and an even larger one Here.

And yes, the CAI and Short ram is a power mod. You can /try/ it, but hook it up to something to see what mileage you are getting first, compare afterwards, you might get lucky. My guess is that your money will be spent better elsewhere though if you're looking for efficiency If it helps as an example, the stock intake on my car is modified, but i bought nothing aftermarket, simply removed my resonators. Someone made a good point that it may not have doing that in which made it "more efficient", however, the purpose of me /not/ having bought an aftermarket intake for my car is that i've seen dyno charts, how it affected the car, and also the reported miles per gallon afterwards which was decreased. That's just for my car though, like i said, every ECU tunes differently, some even adapt to measurements differently though the concept is similar.

I've seen a few belly pan setups on here searching through the thread. Some people have used setups where they used aluminum sheets or other things like hard plastics and used bolts with clips on the end that "clip onto" the subframe or frame or part of the car so you aren't drilling into anything (if that's what you are worried about). In the thread in Daox's thread he uses choroplast (I'm assuming you can probably buy in sheets at home depot or what not).

I'm heavily considering doing a belly pan to my car and that would be the route i'd take because I don't want to drill into any part of my subframe or the car itself.

You want to use something though that will be rigid enough that it isn't going to flap in the wind or come loose.

[thevisionseeker]

haha ya man me either.
I totally understand what you mean now. Like I said I'm still trying to get past the whole power mod thing and become for efficient. Saving money is always best.

How much mpg are we talking about with this underbelly pan? I mean if its a good amount then why wouldn't every manufacturer be doing it? Just another concern of mine.