MS CAi and Gas mileage

[Pondo]

Do you guys think that the MS CAI can cause the car to burn more gas than without it?

Thanks for your replies.

[mazdaspeedster3]

Yea, you like hearing the turbo and BPV so you are on the gas more.

[CWPspeed3]

Yea, you like hearing the turbo and BPV so you are on the gas more.

Exactly, the car will actually be capable of getting better gas mileage with a freer breathing intake but you will like the noise it makes more so you will get into the throttle just to hear it Unless you have really good self control and are that worried about gas mileage.

[mazdaspeedster3]

MS3/Selfcontrol..... FAIL! :-)

[camrycev6]

Do you guys think that the MS CAI can cause the car to burn more gas than without it?

Thanks for your replies.


I did not notice any signficant difference in gas mileage before or after my MS CAI. However, logically if it is making more power, it is likely using a little more fuel --- but nothing to worry about.

[mazdaspeedster3]

How does power equate to fuel usage? It is creating power from better air flow. CAI does not cause more fuel usage does it?

[camrycev6]

How does power equate to fuel usage? It is creating power from better air flow. CAI does not cause more fuel usage does it?

It is clearly more complicated than just saying more power equals more fuel. That wasn’t what I was trying to convey. You are correct that A/F mixes, burn temperatures / pressures, friction, etc., all play roles in extracting the most power from fuels. However, all other things being equal, you can't get something for nothing. The CAI may allow the engine to act more efficiently, so that power gain does not equal an increase in fuel consumption. (Or only a minor one.) Still, you can only do so much to increase the power of an engine without consuming more fuel. Eventually, you can no longer increase the efficiency of the engine, and by the laws of physics, you have to increase your fuel usage.

[mazdaspeedster3]

I was under the impression that the original idea of CAI's were for fuel efficiency gains.

[Pondo]

have you guys noticed reduced gas mileage with the CAI installed? My car is only a year old, but i've noticed poor gas mileage in the past months.

[camrycev6]

I was under the impression that the original idea of CAI's were for fuel efficiency gains.

It was my understanding that it was for power gains, not fuel efficiency. After all, a Cold Air Intake is specifically there to increase the density of the air in the cylinder, thereby creating more pressure during ignition and subsequently increasing power output. By adding more "air" to the mix, you would have to increase the fuel to maintain the same air / fuel mix.

Of course, it would all come down to how the computer handles the increased air density since A/F are constantly ajusted on modern vehicles.

[camrycev6]

have you guys noticed reduced gas mileage with the CAI installed? My car is only a year old, but i've noticed poor gas mileage in the past months.

I noticed a slight decrease in gas mileage after installing the CAI on both of my MS3s. I expected a minor decrease, and it has not been a problem.

[CWPspeed3]

have you guys noticed reduced gas mileage with the CAI installed? My car is only a year old, but i've noticed poor gas mileage in the past months.

I've actually noticed an increase in my gas mileage after installing a sri, then again my car had less than 3k miles when I put it on so it may have still been breaking in.

[sunny4201]

The dealership said that it is supposed to increase gas mileage.

[happy and angry]

How does power equate to fuel usage? It is creating power from better air flow. CAI does not cause more fuel usage does it?More power generally involves burning more fuel. You can do a few things to improve power: you can burn more fuel, more efficiently burn the fuel you have available, or decrease mechanical resistance and thus mechanical power loss (think lightweight pulleys). Our turbo essentially allows us to burn more fuel by providing more air (oxygen) with which to burn more fuel.

So how does an intake provide more power? Two ways. You get colder (and thus more dense) air, which again means we can burn more fuel. It also allows air to move more freely. The motor works less to suck in the same volume of (now more dense) air, as there is less in the way to restrict air flow. This is why an SRI or a CAI provide such similar power gains on our car - Cobb tuning called our stock air box one of the most restrictive they have ever seen.

We have motors that run pretty rich stock. There is a lot of extra fuel in the cylinder each cycle, and we don't burn it all. An intake should provide more air (colder, more dense air) so we can burn more of it which produces more power, and allows air to flow more freely so we lose less power pulling in air.

All of this adds up to a more efficient engine. You make better use of the fuel you have available, you lose less power due to air restriction.

[pdqgp]

Yes. The car is going to utilize the extra air and burn more efficiently but the ECU will adjust to the extra air and your car will still essentially run rich as it does from the factory. That's good on a turbo though. Lean runs will turn your pistons into ashtrays and your ECU knows that.


Do you guys think that the MS CAI can cause the car to burn more gas than without it?

Thanks for your replies.

[strytnyne]

im getting 28 mpg stock 70highway.30 city with 2500miles..what would i be expecting if cobb ever comes out of backorder ^^

[Russm]

Good Day
Silver 08
MSCAI, MSCBE, 27MPG combined,32+ Hwy 18k , synthetic 5/30.
Restraint can still be fun!

[camrycev6]

More power generally involves burning more fuel. You can do a few things to improve power: you can burn more fuel, more efficiently burn the fuel you have available, or decrease mechanical resistance and thus mechanical power loss (think lightweight pulleys). Our turbo essentially allows us to burn more fuel by providing more air (oxygen) with which to burn more fuel.

So how does an intake provide more power? Two ways. You get colder (and thus more dense) air, which again means we can burn more fuel. It also allows air to move more freely. The motor works less to suck in the same volume of (now more dense) air, as there is less in the way to restrict air flow. This is why an SRI or a CAI provide such similar power gains on our car - Cobb tuning called our stock air box one of the most restrictive they have ever seen.

We have motors that run pretty rich stock. There is a lot of extra fuel in the cylinder each cycle, and we don't burn it all. An intake should provide more air (colder, more dense air) so we can burn more of it which produces more power, and allows air to flow more freely so we lose less power pulling in air.

All of this adds up to a more efficient engine. You make better use of the fuel you have available, you lose less power due to air restriction.

Bingo... What I was saying as well, but HappyandAngry gave a more lengthy explanation.

[dread]

my mpg's went up by 3mpg after installing the ms cai.

[camrycev6]

my mpg's went up by 3mpg after installing the ms cai.

Who knows then... on both my MS3s, after the MS install, they MPG went down slightly. I am pretty meticulous about measuring my MPGs, so of course I was never using the trip computer to gage it. Clearly this could be explained by a myriad of factors. Driving styles, climate, HWY/CTY driving miles, etc.

[marashka]

The difference in mpg, from intake will be very minimal. If your driving habits remain exactly the same - theoretically it should increase, but most people i know tend to drive car just a little harder after installing modifications.
On the other note how do you guys get such an incredible mileage of 27 ...28 etc? I get 23 mpg on my trip computer (which in real world translates to 20-21 i guess) and that's with 60-70% freeway driving. Gotta work on my self control with that gas pedal...

[FORZDA 1]

The difference in mpg, from intake will be very minimal. If your driving habits remain exactly the same - theoretically it should increase, but most people i know tend to drive car just a little harder after installing modifications......

In the "old" days of carburators and early fuel injected cars this was indeed true. More air into the engine would lean it out slightly which does make more power and consequently less fuel for a given power out. In newer (read Speed3/6 series) cars, the air is measured precisely and fuel added accordingly to maintain the stoic or target AFR. The CAI, if it is doing what it is intended to provide cooler (ie denser) air, will theoretically result in LESS mpg with all other variables constant... If you're getting better mpg, you're likely driving "softer" because you can hear the intake sucking.

[happy and angry]

True to a point, but the stock air box is incredibly restrictive. Less energy is spent pulling air into the motor, which means an overall more efficient engine. This is probably the major reason why people see better fuel economy. ~1 mpg is a normal gain.

[camrycev6]

The difference in mpg, from intake will be very minimal. If your driving habits remain exactly the same - theoretically it should increase, but most people i know tend to drive car just a little harder after installing modifications.
On the other note how do you guys get such an incredible mileage of 27 ...28 etc? I get 23 mpg on my trip computer (which in real world translates to 20-21 i guess) and that's with 60-70% freeway driving. Gotta work on my self control with that gas pedal...

I just finished a recent post comparing actual verus trip computer mileage. After over 900 miles of about 60 HW / 40 City, I was getting 24.1 MPG, so really I am not that far from you. I don't get above 25 MPG unless I am driving a lot of HWs and for long periods of time. (And close to the speed limit...)

[marashka]

I just finished a recent post comparing actual verus trip computer mileage. After over 900 miles of about 60 HW / 40 City, I was getting 24.1 MPG, so really I am not that far from you. I don't get above 25 MPG unless I am driving a lot of HWs and for long periods of time. (And close to the speed limit...)

good info!
Close to the speed limit is the key for better mileage.

[assman]

I get about 6MPG better with my CP-E. Lovin-It!!!

[happy and angry]

I can pretty much guarantee that you do not get a 20-25% increase in fuel economy with your CP-E intake.

[marashka]

I can pretty much guarantee that you do not get a 20-25% increase in fuel economy with your CP-E intake.

what he said.

[assman]

I went from about 10L/100km I think 23mpg ish to 8L/100km 29 mpg. My car was a pig when I first bought it.

[FrequentFlyer]

I have not noticed an increase in mpg with my Cobb SRI.

[camrycev6]

I went from about 10L/100km I think 23mpg ish to 8L/100km 29 mpg. My car was a pig when I first bought it.

I am not making any accusations here assman. (Boy that sounds strange saying that...)

Anyway, I would like to see some more data on this compared to others. We need a lot more than a tank or two's worth of data. Frankly, I have a hard time (from a physics standpoint) believing that adding a CAI not only adds 20+ HP, but it also gives you 4-5 better MPG! That sounds a little too good to be true. I got the HP, but my mileage has essentially remained the same, or dropped slightly from time to time. I have data for well over 1000 miles of driving with and without the CAI.

[happy and angry]

I have no problem saying it's too good to be true. It simply is too good to be true. There is another explanation for what he is seeing. His ECU getting smarter, getting through break in, a change in driving habits, etc etc etc. He is not getting a 20 - 25% increase in fuel economy from an intake alone.

[assman]

1. Ok so here it is, is the fact that my mileage was uber shitty before at 23mpg not believable?

2. Or is it inconceivable that I get 29mpg now? Is this higher then normal on the board? I think not.

I dont have the data with me, or maybe even at all. I have been recording my mileage and amount of gas put in into a notepad in my car for a while now but Im not sure how old it is or when exactly I had put on my intake, since its been on so long.

All I know is this. My mileage calculator in the car has always read about 1L/100km higher then normal. Before it used to say 11 avg now its closer to 9. But as said its real life #'s are closer to 8 and 10.


I have no reason to make any of this up. I just posted in this thread simply to give the data the member requested although my intake is CPE rather then MS.

So in conclusion, I dont expect I will defend myself anymore or try and find some data which you would probably say I faked anyways. I had a car from the factory that got absofuckinglutly bad gas mileage. It got a bit better after an ECU flash but was still aweful. Now its great.

That is all.

[camrycev6]

1. Ok so here it is, is the fact that my mileage was uber shitty before at 23mpg not believable?

2. Or is it inconceivable that I get 29mpg now? Is this higher then normal on the board? I think not.

I dont have the data with me, or maybe even at all. I have been recording my mileage and amount of gas put in into a notepad in my car for a while now but Im not sure how old it is or when exactly I had put on my intake, since its been on so long.

All I know is this. My mileage calculator in the car has always read about 1L/100km higher then normal. Before it used to say 11 avg now its closer to 9. But as said its real life #'s are closer to 8 and 10.


I have no reason to make any of this up. I just posted in this thread simply to give the data the member requested although my intake is CPE rather then MS.

So in conclusion, I dont expect I will defend myself anymore or try and find some data which you would probably say I faked anyways. I had a car from the factory that got absofuckinglutly bad gas mileage. It got a bit better after an ECU flash but was still aweful. Now its great.

That is all.

(Sigh)... Relax Assman. No need to go on the defensive. This is the response I was trying to avoid. I am simply saying if you wouldn't mind providing some more data in the future, that would be great. If you don't feel like it, no problem.

However, I must point out one premise that is incorrect from the start. In your statement #2, you point out that averaging 29 MPG in not higher than normal on the board. Sorry sir, but that is incorrect. If you do a thorough search of posts relating to gas mileage, the vast majority of MS3 users are getting between 23-26 MPG on a consistent basis. 29 is by no means close to the majority.

[happy and angry]

I'm not saying your mileage calculations/numbers are wrong, I'm saying that much of an improvement can't be attributed to a CAI alone.

[strytnyne]

most mileage can be gained from driving habits

[Rotus8]

most mileage can be gained from driving habits
+1
My normal milage has been 22-23 for the last year or so. When gas went through the roof, I miraculously started getting 25-26. On a road trip last weekend I got 30.5! (That last one was 95% freeway and my wife was in the car. Makes a huge difference.)

[Russm]

Control of or Lack There Of!

[camrycev6]

+1
My normal milage has been 22-23 for the last year or so. When gas went through the roof, I miraculously started getting 25-26. On a road trip last weekend I got 30.5! (That last one was 95% freeway and my wife was in the car. Makes a huge difference.)

Sure Rotus8, I hear you. I once got 31 MPG driving 50 mpg in sixth gear for over 70 miles towards Ocean City. Getting that kind of mileage is the exception not the rule. I noticed your normal mileage is exactly in line with what I was saying 23-26.