All other variables being equal, which would achieve better MPG, a K & N filter, or a paper filter (STP, Fram, etc)?
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Which obtains better MPG: K & N or paper filter?
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I would say the same.
I'd also say the same, unless the paper one is dirty. Then K & N might be marginally better.
No difference at all
On a modern EFI, no difference.
which ever one is the MOST restrictive - less air in means less fuel in (assuming an otherwise properly functioning EFI system)
ToyotaNSaturn
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Originally Posted By: calvin1
which ever one is the MOST restrictive - less air in means less fuel in (assuming an otherwise properly functioning EFI system)
I was thinking along those lines. Both sides of the logic argument make sense though.
which ever one is the MOST restrictive - less air in means less fuel in (assuming an otherwise properly functioning EFI system)
I was thinking along those lines. Both sides of the logic argument make sense though.
it's better to control that w/ your right foot. i would say K&N is better, but it will also allow more dirt in so stick w/ dry filters unless you're willing to trade wear for performance
Even if one did, I would imagine the difference would be small enough it would take a very long time to generate any savings, especially after you factor in the cost of the filter.
Well K&N is suppose to be, they let more air in thus easer breathing,but you know the down side to the ol stone catcher is.
Originally Posted By: daman
Well K&N is suppose to be, they let more air in thus easer breathing,but you know the down side to the ol stone catcher is.
You know what really keeps my engine from breathing easier? The throttle plate! I bet if I wired the throttle wide open I'd get great gas mileage!
Well K&N is suppose to be, they let more air in thus easer breathing,but you know the down side to the ol stone catcher is.
You know what really keeps my engine from breathing easier? The throttle plate! I bet if I wired the throttle wide open I'd get great gas mileage!
Originally Posted By: calvin1
Originally Posted By: daman
Well K&N is suppose to be, they let more air in thus easer breathing,but you know the down side to the ol stone catcher is.
You know what really keeps my engine from breathing easier? The throttle plate! I bet if I wired the throttle wide open I'd get great gas mileage!
Sure,that would do it. try it and please post back?
Originally Posted By: daman
Well K&N is suppose to be, they let more air in thus easer breathing,but you know the down side to the ol stone catcher is.
You know what really keeps my engine from breathing easier? The throttle plate! I bet if I wired the throttle wide open I'd get great gas mileage!
Sure,that would do it. try it and please post back?
The one that's less restrictive, all other things being equal. Things tend to not ever be equal in real life. I noticed a very slight increase when using K&N and attempting to drive the same way. That was no where near scientific since temperature, humidity and other factors like stop lights, etc. cannot be controlled. Also, once the K&N filter is installed people normally try to see how much more power they have, which negates any increase in pumping efficiency of the engine.
Remember, the engine is an air pump. The easier it is to get the air in, the less the pumping loss will be. The engine draws the air in by creating a low pressure area when the piston moves down in its bore. The air filter and flow restrictions in the intake tract all the way from the air cleaner to the valve provide resistance to allowing the air to fill the low pressure area. The piston is going to move down regardless, but the less restrictive the path of air is the less the pumping loss.
Imagine an extreme example where there is complete 100% restriction. The piston will be working against a vacuum on the top side of the piston attempting to pull the piston up instead of down, the direction the rod is pulling it. This effect may be so very slight but still forces the engine to constantly work against itself. This phenomenon is always happening at least slightly since there will always be some restriction in the air flow path to the combustion chamber.
Please don't take this as an endorsement of K&N filters. I use them in performance vehicles to gain a slight bit of HP but I use Amsoil EaA filters in my other vehicles due to the superior filtering ability vs. K&N.
Remember, the engine is an air pump. The easier it is to get the air in, the less the pumping loss will be. The engine draws the air in by creating a low pressure area when the piston moves down in its bore. The air filter and flow restrictions in the intake tract all the way from the air cleaner to the valve provide resistance to allowing the air to fill the low pressure area. The piston is going to move down regardless, but the less restrictive the path of air is the less the pumping loss.
Imagine an extreme example where there is complete 100% restriction. The piston will be working against a vacuum on the top side of the piston attempting to pull the piston up instead of down, the direction the rod is pulling it. This effect may be so very slight but still forces the engine to constantly work against itself. This phenomenon is always happening at least slightly since there will always be some restriction in the air flow path to the combustion chamber.
Please don't take this as an endorsement of K&N filters. I use them in performance vehicles to gain a slight bit of HP but I use Amsoil EaA filters in my other vehicles due to the superior filtering ability vs. K&N.
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You know what really keeps my engine from breathing easier? The throttle plate! I bet if I wired the throttle wide open I'd get great gas mileage!
Are you a Toyota engineer?
Are you a Toyota engineer?
Originally Posted By: ledslinger
You know what really keeps my engine from breathing easier? The throttle plate! I bet if I wired the throttle wide open I'd get great gas mileage!
Are you a Toyota engineer?
Nope, just showing how silly it is to say "letting air into the engine gives better gas mileage". That's exactly the same as saying that flooring the gas pedal will give you better mileage than at idle. Just think how much lower the pumping losses are at WOT! ... We all know that obviously can't be true. If it's true for the gas pedal at WOT it's also true for the air filter paper vs. K&N. Letting more air into the engine means you're also letting more gas into it.
More air in? >>> More gas in.
More gas in? >>> Less MPG.
Pumping losses across the air filter are incredible small; so small that I'd be surprised if it is even quantifiable compared to the rest of the drive-train losses.
You know what really keeps my engine from breathing easier? The throttle plate! I bet if I wired the throttle wide open I'd get great gas mileage!
Are you a Toyota engineer?
Nope, just showing how silly it is to say "letting air into the engine gives better gas mileage". That's exactly the same as saying that flooring the gas pedal will give you better mileage than at idle. Just think how much lower the pumping losses are at WOT! ... We all know that obviously can't be true. If it's true for the gas pedal at WOT it's also true for the air filter paper vs. K&N. Letting more air into the engine means you're also letting more gas into it.
More air in? >>> More gas in.
More gas in? >>> Less MPG.
Pumping losses across the air filter are incredible small; so small that I'd be surprised if it is even quantifiable compared to the rest of the drive-train losses.
calvin < physics -you're also forgetting that fuel maps in the PCM will prob allow the mix to go rich when less air gets in, instead of matching it exactly with less fuel and risking a lean cond. rich = safer for all the manufac
it also depends on how restrictive your stock intake is. on the 4th gen LT1 camaros there were repeated dyno results showing 15-19hp gains w/ the K&N intake. so in my mind the best solution is the K&N intake but using the Amsoil Ea4070 air filter. and yes that also translates to better mpg, but so does grandma driving
it also depends on how restrictive your stock intake is. on the 4th gen LT1 camaros there were repeated dyno results showing 15-19hp gains w/ the K&N intake. so in my mind the best solution is the K&N intake but using the Amsoil Ea4070 air filter. and yes that also translates to better mpg, but so does grandma driving
Originally Posted By: calvin1
Originally Posted By: daman
Well K&N is suppose to be, they let more air in thus easer breathing,but you know the down side to the ol stone catcher is.
You know what really keeps my engine from breathing easier? The throttle plate! I bet if I wired the throttle wide open I'd get great gas mileage!
Hey dude? did you ever try this? please try it immediately and post back?
Originally Posted By: daman
Well K&N is suppose to be, they let more air in thus easer breathing,but you know the down side to the ol stone catcher is.
You know what really keeps my engine from breathing easier? The throttle plate! I bet if I wired the throttle wide open I'd get great gas mileage!
Hey dude? did you ever try this? please try it immediately and post back?
Originally Posted By: [RT
ProjUltraZ]calvin < physics -you're also forgetting that fuel maps in the PCM will prob allow the mix to go rich when less air gets in, instead of matching it exactly with less fuel and risking a lean cond. rich = safer for all the manufac
it also depends on how restrictive your stock intake is. on the 4th gen LT1 camaros there were repeated dyno results showing 15-19hp gains w/ the K&N intake. so in my mind the best solution is the K&N intake but using the Amsoil Ea4070 air filter. and yes that also translates to better mpg, but so does grandma driving
Even if this was about intake swaps, which it isn't, hp<>mpg. You might have also noticed that the more HP on tap the lower the MPG, just generally speaking.
Also, where are you getting this about fuel maps running rich?!?!? The only time that happens is at or close to WOT, which again is not really relevant to someone looking to get the best mileage. At all other times an EFI system is at or close to a stoichiometric (perfect) mix or it's broken. The O2 sensor says either "lean" or "rich" and it's up to the ECM to nudge it back the opposite way until the signal changes, repeat. If it runs consistently lean you'll melt valves and pistons, rich and you'll line the cylinder and exhaust with carbon.
Someone please just explain how getting more fuel to the engine gives you better mileage, not power, mileage.
ProjUltraZ]calvin < physics -you're also forgetting that fuel maps in the PCM will prob allow the mix to go rich when less air gets in, instead of matching it exactly with less fuel and risking a lean cond. rich = safer for all the manufac
it also depends on how restrictive your stock intake is. on the 4th gen LT1 camaros there were repeated dyno results showing 15-19hp gains w/ the K&N intake. so in my mind the best solution is the K&N intake but using the Amsoil Ea4070 air filter. and yes that also translates to better mpg, but so does grandma driving
Even if this was about intake swaps, which it isn't, hp<>mpg. You might have also noticed that the more HP on tap the lower the MPG, just generally speaking.
Also, where are you getting this about fuel maps running rich?!?!? The only time that happens is at or close to WOT, which again is not really relevant to someone looking to get the best mileage. At all other times an EFI system is at or close to a stoichiometric (perfect) mix or it's broken. The O2 sensor says either "lean" or "rich" and it's up to the ECM to nudge it back the opposite way until the signal changes, repeat. If it runs consistently lean you'll melt valves and pistons, rich and you'll line the cylinder and exhaust with carbon.
Someone please just explain how getting more fuel to the engine gives you better mileage, not power, mileage.
Originally Posted By: daman
Originally Posted By: calvin1
Originally Posted By: daman
Well K&N is suppose to be, they let more air in thus easer breathing,but you know the down side to the ol stone catcher is.
You know what really keeps my engine from breathing easier? The throttle plate! I bet if I wired the throttle wide open I'd get great gas mileage!
Hey dude? did you ever try this? please try it immediately and post back?
Not wired that way but I have gone WOT and every time I get more HP and less MPG than cruise. It's funny how that works.
Originally Posted By: calvin1
Originally Posted By: daman
Well K&N is suppose to be, they let more air in thus easer breathing,but you know the down side to the ol stone catcher is.
You know what really keeps my engine from breathing easier? The throttle plate! I bet if I wired the throttle wide open I'd get great gas mileage!
Hey dude? did you ever try this? please try it immediately and post back?
Not wired that way but I have gone WOT and every time I get more HP and less MPG than cruise. It's funny how that works.
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