anybody experience better fuel efficiency with an aftermarket intake? what kind of intake?

 

shouldnt have any affect, but if it did, itd be negative. more air coming in = more fuel = worse fuel economy

 

not true at all...more air equals "easier to breathe."

I've had intakes on all my cars and they've all *HELPED with my mpg. Anyone else experience this? I understand the theory though; how more air would equal more gas to maintain the same air/fuel ratio (given the the ECU corrects itself and add more gas when it detects more air)...but just from experience...I've never had a decrease in mpg. Not in the S2000 or Civic.

 

Er... more air coming in + more fuel = more power/better efficiency/bettercombustion characteristics = more energy used from fuel at lower RPMs = less throttle needed = better fuel economy.

 

When you think of an engine as a big air pump the less work it takes to suck in that intake air (as well as push out all those combustion products)the more efficient the engine and thus better mpg.
Thus more efficient intakes, measured by air flow at a given pressure differential, the more efficient intake will use less gas.
Needless to say very careful port matching on assembly is critical too.
And of course taken to the ultimate each intake track may be slightly different to equalize and maximize the air flow from valve opening to valve closing. like you my and others finished intakes all produced better mpg. some of my development manifolds had enormous mpg losses. Lots of times it just didn't make sense.

 

No, aftermarket intakes should not affect fuel economy. First, most of the restriction is due to the throttle plate. A less restrictive intake only helps during WOT, which is not good for fuel economy. Second, the car reads the amount of air coming in and calculated the amount of fuel that is needed.

 

intake is good and all but what about aftermarket exhaust even on small engines dont they need some back pressure to help with horse power and even torque so even if it can suck in air better and exhaust it faster is there a such thing as too fast? and well the ECU cut power to try to heal this and if so what would be good for the 09 FIT god i hope im making scene...

 

I got minor improvement in MPG in my accord with AEM CAI on it. It only made like 1-2mpg average difference with the KN filter head it came with. Your mileage should be the same or a lil better, if you aren't flooring it to hear it. If you like the sound of your intake a lot, chances are your MPG will go down a bit

 

If you had ever run air flow tests on intake manifolds you would know that good ones decrease air flow resistance across the board, meaning the pressure drop across the manifold passages is reduced from idle on up. While the major resistance is indeed the throttle plate the overall reduction still leads to better mpg .
There are specialised or inept manifolds that do have more pressure drop at other air flows than WOT; most are for racing efforts as at Daytona.
Just making the passages bigger is more often not correct.There is an optimum air velocity that matters most.
Building manifolds is another one of those black arts. Perhaps computer moldeling has progressed to a science nowdays but not may will advertise it.

 

If better fuel efficiency could be had by a simple design change of the intake or exhaust then Honda would have done it. That's their goal.

Better performance at the expense of fuel economy (loss) is another thing.

 

You need to visit a NASCAR race shopand see the stacks and stacks of manifolds on hand to try variations on the 'stock' passage designs to improve performance and mpg (especially now that so many races are won on mpg). They spend a lot more time developing manifolds than Honda would do considering the extra cost for them. They get close and compare costs and ease of assembly for producuing tens of thousands of manifolds not 100.If someone's design proved better Honda would no doubt buy or approximate that design if it worked on mass production. A manifold design is never simple.

 

:sigh:. .................

 

The real reason honda doesn't run intakes or exhausts is for noise. The average car driver wants a quiet ride. They try to balance power, economy, and sound levels. The more you can quiet an engine on either opening the less sound insulation needs to be used in the car, resulting in weight savings and that equals better economy.

On my RR it has an intake flapper that closes to make it idle more quietly. By adding the flapper valve it maintains quiet levels at idle, but when you get on it, the flap opens allowing a more aggressive intake path. And if you cut open a factory exhaust canister, its not a straight through or just a baffle or two, its shaped like a nautilus shell, so they are modeling it organically after nature. It maintains high flow while minimising engine noise.

Honda designs products for the average consumer in their target market, while allowing the design to be easily modified by aftermarket without sacrificing reliability, which is also why the ECU's actually can detune mods over time. Honda is super smart. Half of the intake boxes on most hondas are just resonator mufflers, designed to make the engine more quiet. As fuel efficient and powerful as honda motors are per liter, the long standing complaint is noisey engines by reviewers. I personally love the sound of a honda takin a deep breath

 

........... :laugh!:

 

Its the work the engine has to perform to suck air/fuel mixture into the cylinders engine that makes the difference, not the amount of air or fuel.