Smart filter
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Generally speaking.. Free flowing and better filtering do not go hand in hand.
Most stock systems and filters flow more than required for WOT operation. You're probably not going to get any improvements on either side of your scale swapping filters around, sorry to say.
Most stock systems and filters flow more than required for WOT operation. You're probably not going to get any improvements on either side of your scale swapping filters around, sorry to say.
You have to pick: do you want it to flow better than stock, or filter better than stock?
Originally Posted By: RamFan
Any reason why?
This. Are you looking for hp gains? From a 1L inline 3 cylinder engine pushing 70 HP stock? Good luck with that.
Any reason why?
This. Are you looking for hp gains? From a 1L inline 3 cylinder engine pushing 70 HP stock? Good luck with that.
There are likely European websites that cater to that car. The biggest gain in performance would be from improving the way the transmission performs. I would try to see if anyone has figured out ways of making it work better.
If you are looking for mpg increase, most fuel injected engines just don't care what filter is on there. I'd go with stock or a purolator pure one. More flow is not going to do much for mpg, so go for better filtration.
Originally Posted By: Virtuoso
Generally speaking.. Free flowing and better filtering do not go hand in hand.
Most stock systems and filters flow more than required for WOT operation. You're probably not going to get any improvements on either side of your scale swapping filters around, sorry to say.
Agree
Contrary to what some filter manufacturers say, there are no gains to be had, from a modern car, in stock condition, by switching away from the stock filter.
Generally speaking.. Free flowing and better filtering do not go hand in hand.
Most stock systems and filters flow more than required for WOT operation. You're probably not going to get any improvements on either side of your scale swapping filters around, sorry to say.
Agree
Contrary to what some filter manufacturers say, there are no gains to be had, from a modern car, in stock condition, by switching away from the stock filter.
Get a Purolator Pureone.
Yep, this is all on track so far.
Commonly, the only way you can reduce restriction AND maintain (or improve) efficiency is to increase the area of the media (increasing it more if you go with a more efficiency). That would require the modification of the air filter housing and ducting, none of which is an eyeball measurement if you want to go forward and not back.
What was said above about airflow is right. There won't be much, if any, power to be had on a stock engine with a replacement element. Similarly, there is virtually no fuel economy to be had either. Where you CAN see a benefit is by going with a more efficient filter and letting it do it's work without constant interference. The air intake system is the lubrication system's biggest source of external contamination. The cleaner the intake air, the cleaner the oil and the longer the engine oil, and the engine, lives.
Best advice:
1) Use a premium level, name brand replacement air filter.
2) Make sure it is seals well in the housing. Use air filter grease as indicated
3) Leave it the heck alone for the specified interval because filter efficiency improves as it loads up.
a) Alternatively, add an air filter restriction gauge (google FilterMinder) and
replace the filter when indicated. This allows you to change the filter at the
RIGHT time, not some arbitrary point. Remember the statistic: 90 percent of the
dirt that passes thru an air filter in it's operational life does so in the first 10
percent of use as the filter loads up. Constant or too often filter changes are
counter productive to engine life.
Commonly, the only way you can reduce restriction AND maintain (or improve) efficiency is to increase the area of the media (increasing it more if you go with a more efficiency). That would require the modification of the air filter housing and ducting, none of which is an eyeball measurement if you want to go forward and not back.
What was said above about airflow is right. There won't be much, if any, power to be had on a stock engine with a replacement element. Similarly, there is virtually no fuel economy to be had either. Where you CAN see a benefit is by going with a more efficient filter and letting it do it's work without constant interference. The air intake system is the lubrication system's biggest source of external contamination. The cleaner the intake air, the cleaner the oil and the longer the engine oil, and the engine, lives.
Best advice:
1) Use a premium level, name brand replacement air filter.
2) Make sure it is seals well in the housing. Use air filter grease as indicated
3) Leave it the heck alone for the specified interval because filter efficiency improves as it loads up.
a) Alternatively, add an air filter restriction gauge (google FilterMinder) and
replace the filter when indicated. This allows you to change the filter at the
RIGHT time, not some arbitrary point. Remember the statistic: 90 percent of the
dirt that passes thru an air filter in it's operational life does so in the first 10
percent of use as the filter loads up. Constant or too often filter changes are
counter productive to engine life.
While generally things are right in this thread, there is a difference between synthetic fibers and cellulose fibers. You CAN make a better filtering filter, without increasing media size and without sacrificing flow using smaller filtration fibers. And you can make a better flowing filter without sacrificing filtration and/or increasing media area.
Everything is a compromise but not all media is the same.
Everything is a compromise but not all media is the same.
Last edited:
Originally Posted By: badtlc
While generally things are right in this thread, there is a difference between synthetic fibers and cellulose fibers. You CAN make a better filtering filter, without increasing media size and without sacrificing flow using smaller filtration fibers. And you can make a better flowing filter without sacrificing filtration and/or increasing media area.
Everything is a compromise but not all media is the same.
Well, you're right and I shoulda mentioned it.
Full syn media replacement air filters are not all that common, yet, so whether one might be available for an application as obscure as the Smart is a big question. Blended aftermarket media is more common but, AFAIK, those filters do not flow better but they should be a bit more efficient at the same restriction. Across the line of OE replacement filters, specific efficiency and restriction info is not easily obtained.
While generally things are right in this thread, there is a difference between synthetic fibers and cellulose fibers. You CAN make a better filtering filter, without increasing media size and without sacrificing flow using smaller filtration fibers. And you can make a better flowing filter without sacrificing filtration and/or increasing media area.
Everything is a compromise but not all media is the same.
Well, you're right and I shoulda mentioned it.
Full syn media replacement air filters are not all that common, yet, so whether one might be available for an application as obscure as the Smart is a big question. Blended aftermarket media is more common but, AFAIK, those filters do not flow better but they should be a bit more efficient at the same restriction. Across the line of OE replacement filters, specific efficiency and restriction info is not easily obtained.
Originally Posted By: expat
Originally Posted By: Virtuoso
Generally speaking.. Free flowing and better filtering do not go hand in hand.
Most stock systems and filters flow more than required for WOT operation. You're probably not going to get any improvements on either side of your scale swapping filters around, sorry to say.
Agree
Contrary to what some filter manufacturers say, there are no gains to be had, from a modern car, in stock condition, by switching away from the stock filter.
If there was any power gain from a more free flowing air filter on a computer controlled engine, it would only be at wide open throttle conditions. Otherwise, as mentioned before by others, the various sensors & computer will compensate for correct A/F ratio if the filter is restrictive or not. To get the same engine power with a restrictive filter, the throttle plate will just have to open a little bit more to get the same air flow through the filter and into the engine. But when at WOT, that all goes away and a restrictive filter will indeed cut down some power by choking off some air, even on a computer controlled engine.
On the other hand, on engines that are not computer controlled, a better flowing air filter would increase power at any given throttle opening if the carburetor was re-jetted to take advantage of any increased air flow at any given throttle opening.
Originally Posted By: Virtuoso
Generally speaking.. Free flowing and better filtering do not go hand in hand.
Most stock systems and filters flow more than required for WOT operation. You're probably not going to get any improvements on either side of your scale swapping filters around, sorry to say.
Agree
Contrary to what some filter manufacturers say, there are no gains to be had, from a modern car, in stock condition, by switching away from the stock filter.
If there was any power gain from a more free flowing air filter on a computer controlled engine, it would only be at wide open throttle conditions. Otherwise, as mentioned before by others, the various sensors & computer will compensate for correct A/F ratio if the filter is restrictive or not. To get the same engine power with a restrictive filter, the throttle plate will just have to open a little bit more to get the same air flow through the filter and into the engine. But when at WOT, that all goes away and a restrictive filter will indeed cut down some power by choking off some air, even on a computer controlled engine.
On the other hand, on engines that are not computer controlled, a better flowing air filter would increase power at any given throttle opening if the carburetor was re-jetted to take advantage of any increased air flow at any given throttle opening.
I suppose it's safe to say you are both right.
Pumping loss exists but is insignificant in most cases, so while we can debate the fact whether it exists or not, or debate the magnitude, we are debating minutiae of little importance in the real world. Possibly with a few exceptions... such as old school oil bath systems and other dinosaur technology of the past.
It's all variable anyway, according to how the intake system is designed. Some are very or relatively efficient. Others less so. Some mfrs will trade a few HP for a quiet intake. Some systems are very noisy when they don't need to be.
Pumping loss exists but is insignificant in most cases, so while we can debate the fact whether it exists or not, or debate the magnitude, we are debating minutiae of little importance in the real world. Possibly with a few exceptions... such as old school oil bath systems and other dinosaur technology of the past.
It's all variable anyway, according to how the intake system is designed. Some are very or relatively efficient. Others less so. Some mfrs will trade a few HP for a quiet intake. Some systems are very noisy when they don't need to be.
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