Notices
Scion tC 1G Drivetrain & Power Engine and transmission discussions...

CAI and MPG

Thread Tools
 
Search this Thread
 
Old May 18, 2007 | 06:48 PM
  #1  
sgj's Avatar
sgj
Thread Starter
Member
10 Year Member
5 Year Member
SL Member
 
Joined: Mar 2007
Posts: 47
From: Georgia
Default CAI and MPG

I know that a CAI is supposed to hurt your MPG- colder air, more gas, more power, etc.

But how much is it really affected? I would like to get a CAI, but I am not willing to kill my gas mileage in the process.
Old May 18, 2007 | 07:10 PM
  #2  
ack154's Avatar
Senior Member
10 Year Member
5 Year Member
SL Member
iTrader: (7)
 
Joined: Apr 2005
Posts: 16,701
Default

Actually, my mileage increased a bit with my CAI. At least sometimes it seems like it did. It definitely did not hurt my mileage.

I can still easily get 30+ mpg on road trips. And average 25 mpg in town.
Old May 18, 2007 | 07:11 PM
  #3  
Spect2K3's Avatar
Senior Member
10 Year Member
5 Year Member

SL Member
Team ScioNRG
 
Joined: Sep 2005
Posts: 3,201
From: Norwalk, CT
Default

You won't notice any difference in that respect. In fact, i've heard of mpg after installing a CAI improving. Don't worry about it. That should be the last thing on your mind.
Old May 18, 2007 | 10:18 PM
  #4  
beedee's Avatar
Senior Member
10 Year Member
5 Year Member
SoCal tC Club
SL Member
 
Joined: Sep 2006
Posts: 599
Default

the adverse effect is that you love the sound it makes, so you tend to be heavier on the gas so you can hear the 'growl' and thus you burn more fuel...
Old May 18, 2007 | 11:56 PM
  #5  
Tcguy85's Avatar
Senior Member
10 Year Member
5 Year Member
SL Member
 
Joined: Aug 2006
Posts: 2,434
From: Hyde Park, NY
Default

i still get the usual 28mpg with my injen cai. and i open it up and listen to the sweet sound it makes sometimes.
Old May 20, 2007 | 01:46 PM
  #6  
Mid_Life_tC-risis's Avatar
Senior Member
10 Year Member
5 Year Member
SL Member
 
Joined: Apr 2007
Posts: 493
From: Tampa, FL
Default

I track my MPG very carefully and the CAI made no difference. My city/highway driving is about 50/50.

In fact, if you do a lot of city driving the CAI may help mileage due to heat soak of the aluminum pipes. When it's 90 outside I can watch my intake air temp (IAT) climb up to 105 degrees at a long red light. I get 28+ mpg overall, but probably 50mpg right after a long stop.
Old May 21, 2007 | 05:22 PM
  #7  
BrEaK_AwaY's Avatar
Senior Member
10 Year Member
5 Year Member
SL Member
Scion Evolution
 
Joined: Jun 2005
Posts: 4,372
From: Baltimore, MD
Default

it wont change much, but heres a rule of thumb:

cold air (dense air): more power, less mpg
warm air (less-dense air): less power, more mpg
Old May 21, 2007 | 05:38 PM
  #8  
D4u2s0t's Avatar
Member
10 Year Member
5 Year Member
SL Member
 
Joined: Apr 2007
Posts: 76
Default Re: CAI and MPG

Originally Posted by sgj
I know that a CAI is supposed to hurt your MPG- colder air, more gas, more power, etc.

But how much is it really affected? I would like to get a CAI, but I am not willing to kill my gas mileage in the process.

whover told you that was lying. if you drive the same it should actually IMPROVE your mileage, not make it worse.
Old May 21, 2007 | 06:39 PM
  #9  
BrEaK_AwaY's Avatar
Senior Member
10 Year Member
5 Year Member
SL Member
Scion Evolution
 
Joined: Jun 2005
Posts: 4,372
From: Baltimore, MD
Default Re: CAI and MPG

Originally Posted by D4u2s0t
Originally Posted by sgj
I know that a CAI is supposed to hurt your MPG- colder air, more gas, more power, etc.

But how much is it really affected? I would like to get a CAI, but I am not willing to kill my gas mileage in the process.

whover told you that was lying. if you drive the same it should actually IMPROVE your mileage, not make it worse.
who ever told him that was semi-correct, and it will hurt his gas milage (very slightly... and only when its cold out)

cold air (dense air) is more difficult to break down than warm air.

cold air - more power, less mpg
warm air - less mpg, more mpg
Old May 21, 2007 | 06:48 PM
  #10  
Ali_Cat's Avatar
Junior Member
5 Year Member
 
Joined: Oct 2006
Posts: 28
Default

The only reason you would see a drastic drop in fuel economy is if you drive with a lead foot, which you are more likely to do because it sounds so nice at 3k rpm.
Old May 21, 2007 | 09:01 PM
  #11  
D4u2s0t's Avatar
Member
10 Year Member
5 Year Member
SL Member
 
Joined: Apr 2007
Posts: 76
Default Re: CAI and MPG

Originally Posted by BrEaK_AwaY
Originally Posted by D4u2s0t
Originally Posted by sgj
I know that a CAI is supposed to hurt your MPG- colder air, more gas, more power, etc.

But how much is it really affected? I would like to get a CAI, but I am not willing to kill my gas mileage in the process.

whover told you that was lying. if you drive the same it should actually IMPROVE your mileage, not make it worse.
who ever told him that was semi-correct, and it will hurt his gas milage (very slightly... and only when its cold out)

cold air (dense air) is more difficult to break down than warm air.

cold air - more power, less mpg
warm air - less mpg, more mpg
break down?? what exactly do you mean by that... it doesn't get broken down at all, just compressed and ignited... you have it all wrong man...
Old May 21, 2007 | 09:16 PM
  #12  
BrEaK_AwaY's Avatar
Senior Member
10 Year Member
5 Year Member
SL Member
Scion Evolution
 
Joined: Jun 2005
Posts: 4,372
From: Baltimore, MD
Default

read up and learn:

The colder/higher density air of the winter months will allow you to get more power from your engine, however, since fuel doesn't atomize as well with a cold intake charge, your mileage will suffer.

The warmer/lower density air of the summer months will reduce max power (sometimes dramatically so if high humidity is involved as well), however, because fuel so readily atomizes with a hot intake charge, there will be far fewer "rich zones" in the combustion chamber, allowing for more power to be derived from what air and fuel does make it to the combustion chamber.

So, if a hot intake charge yields more power from any given unit of gasoline, why don't you get more power from your engine in the summer time? Simple, your engine measures the weight of the air entering the engine, and then provides a given amount of fuel for every pound of air (typically something a bit over stoichiometric which is roughly 14.9 weight units of air to 1 weight unit of fuel). Since lighter air is entering the engine in hot weather, less fuel is pumped in via the fuel injectors, and so even though you're getting more power per unit of fuel, the max power of the engine is reduced.
Old May 21, 2007 | 10:53 PM
  #13  
D4u2s0t's Avatar
Member
10 Year Member
5 Year Member
SL Member
 
Joined: Apr 2007
Posts: 76
Default

you're talking about summer vs. winter. you can't use the same argument for an intake vs. no intake. that's rediculous. by increasing the air flow through the engine, you're in effect running more LEAN than you were before. the engine will compensate a little bit, but you will run slightly more lean than without an intake. is denser air harder to move? yes... but that's compensated by the higher flow of an aftermarket intake.

the ONLY way an intake will hurt your mileage, and almost ANY vehicle, is if you're driving harder than you did before you put it on.
Old May 21, 2007 | 11:38 PM
  #14  
BrEaK_AwaY's Avatar
Senior Member
10 Year Member
5 Year Member
SL Member
Scion Evolution
 
Joined: Jun 2005
Posts: 4,372
From: Baltimore, MD
Default

Originally Posted by D4u2s0t
is denser air harder to move? yes... but that's compensated by the higher flow of an aftermarket intake.
really? so the CAI is controlling your a/f ratio alone? dont think so... its alot more than that buddy

and im not just saying summer vs winter. a CAI will pull cooler air than a SRI, so its the same concept
Old May 21, 2007 | 11:49 PM
  #15  
D4u2s0t's Avatar
Member
10 Year Member
5 Year Member
SL Member
 
Joined: Apr 2007
Posts: 76
Default

i never said that the cai is controlling your a/f ration alone, did i? your'e fighting a losing battle. you WILL get better gas mileage with an intake. end of story.
Old May 21, 2007 | 11:54 PM
  #16  
D4u2s0t's Avatar
Member
10 Year Member
5 Year Member
SL Member
 
Joined: Apr 2007
Posts: 76
Default

what's next, you get more power from premium over regular??
Old May 22, 2007 | 12:03 AM
  #17  
ack154's Avatar
Senior Member
10 Year Member
5 Year Member
SL Member
iTrader: (7)
 
Joined: Apr 2005
Posts: 16,701
Default

You kids are silly...
Old May 22, 2007 | 12:04 AM
  #18  
D4u2s0t's Avatar
Member
10 Year Member
5 Year Member
SL Member
 
Joined: Apr 2007
Posts: 76
Default

i agree... this is a very silly "argument". haha
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
BlingSlade
Scion iA Discussion Lounge
6
Oct 19, 2016 12:39 AM
mudguy
Scion xB 2nd-Gen Drivetrain & Power
7
Oct 22, 2015 04:31 PM
CrowJenkins
Scion tC 2G Owners Lounge
5
Oct 9, 2015 10:47 PM
olyellr
Introduction Forum
1
Sep 28, 2015 10:32 PM
vi3tb0i09
PPC: Engine / Drivetrain
2
Sep 23, 2015 08:32 PM




All times are GMT. The time now is 12:00 AM.