Improving MPG

5

Asked by Regan Jul 13, 2008 at 08:50 PM about the 2008 Honda Civic Coupe Si

Question type: Car Customization

If I have an AEM cool air intake and a Catback exhaust, will that improve my car's MPG. If so, by how much?

17 Answers

45

No, this will not improve your mileage. It will improve your cars performance, but not the mileage. Performance parts improve power, not mileage. If you plan on any serious upgrades, plan on sacrificing mileage for power.

4 people found this helpful.
5,155

haha are your serious? you bought an si and you want to improve the mileage? you should be modifying it and not worrying about the mileage its a damn si

4 people found this helpful.
5,155

you should of bought the civic hybrid if you were going to worrying about mileage

1 people found this helpful.
120

lol... i think hes looking for an excuse so his mommy and daddy will pay for mods

2 people found this helpful.
125

Yes, modifying your car does increase gas mileage, because it allows the engine to flow a lot better than a restricted exhaust and air box. The engine doesn't have to work as hard. It's not going to be a noticeable difference around town, but on the highway you can add a mpg or two. As long as you keep your foot out of the gas you will increase your gas mileage.

4 people found this helpful.
135

at most just a little the both the mods help but its hardly going to be noticeable.

2 people found this helpful.
10

actually it will improve your mileage... especially if you don't reflash your ECU. However, you will *really* improve your mileage if you drive more smoothly (less hard accelerates and then hard brakes; shifting into neutral when coasting to a red light). Also if you're short shifting (like below 3000rpm) you'll save mileage as well. I have an Si sedan... get around 31mpg just going to work and stuff... (even with dipping into VTEC about 2-3 times a day).

1 people found this helpful.
5

Swap the motor into a 94 civic hatch, you will probably get around 40MPG and still run 12's in the 1/4 mile.

120

hella BAD information in this thread... go to honda-tech.com and search for answers yourself...

1 people found this helpful.
1,075

first off any mods that are not HKS approved will void your waranty to that section you modded. did you buy an extended warany? Is this a track car or a red light warior?( which i do not endorse) is this a six speed stick you already have a fast car! stick with factory approved mods for you may need your warenty unless you have unlimited bankroll

www.mileagewillvary.com..... Check it out. I get 33 with my 2008 SI on the highway. Your car will compensate for the extra air it is taking in, as well as the exhaust flow, and add fuel which will actually decrease gas mileage.

16,745

good idea in theory, but I think you fail to understand what the additional fuel results in... Thats the same as saying... if you step on the peddle more it will use more gas... Well yes, of course that is obvious, but it also results in more force(torque)/speed. The idea of better mileage is to reduce the amount of work the engine has to do to pull air in. The principle is easy to understand.... Grab two straws with the same internal diameter. Breath in through a 5 inch straight one and then through a 6 inch curved one... Which one did you waste more energy trying to breath with? The curved one right? Same principle as a 4-stroke engine on it's intake stroke. This just makes it easier to breath... The problem with most CAI is the fact that they are open element and tend to pull hot air into the engine... This defeats the entire purpose since hot air is less dense.

150

the air intake is actually working against you if you want to increase gas mileage you should probably change your oil more often and try not to be so heavy on the gas. by puting in a high performance air intake and exhaust you will make more air go through the engine and the engine will have to work harder to pump the fuel through the car. in effect you will have to have oil changes more often and you will lower your gas mileage. Aem is a good brand though but you are just using it for the wrong purpose!!!!!!

Your Answer:

Civic Coupe

Looking for a Used Civic Coupe in your area?

CarGurus has 272 nationwide Civic Coupe listings starting at $3,590.

Postal Code:

CarGurus Experts

  • #1
    deb5deb5deb5deb5deb5
    Reputation
    2,850
  • #2
    kd5qhr
    Reputation
    2,390
  • #3
    elmerenzo
    Reputation
    1,490
View All

Find great deals from top-rated dealers

Search

Related Models For Sale

Used Honda Civic
188 Great Deals out of 4,003 listings starting at $440
Used Honda Accord Coupe
6 Great Deals out of 47 listings starting at $5,495
Used Honda Accord
50 Great Deals out of 974 listings starting at $2,995
Used Toyota Camry
48 Great Deals out of 1,142 listings starting at $4,795
Used Toyota Corolla
142 Great Deals out of 2,244 listings starting at $2,699
Used Ford Mustang
46 Great Deals out of 1,664 listings starting at $5,977
Used Lexus IS
20 Great Deals out of 423 listings starting at $4,400
Used BMW 3 Series
65 Great Deals out of 1,206 listings starting at $2,900
Used Honda CR-V
170 Great Deals out of 4,990 listings starting at $440
Used Mazda MAZDA3
76 Great Deals out of 1,320 listings starting at $1,999

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use. Content will be removed if CarGurus becomes aware that it violates our policies.