"C. E. White" > wrote in message
news:47ac6ddf@kcnews01...
>
> "My Name Is Nobody" > wrote in message
> news:vpKqj.6861$Qj3.1135@trndny07...
>
>>> There is no reason that it should be. In fact, if the feedback system is
>>> functioning as designed there should be very little change in the A/F
>>> ratio no matter what you do to the intake. If the PCM can't maintain the
>>> proper A/F ratio, then it should set the check engine light.
>>>
>>> Ed
>>
>> BULL****!
>
> You love to use that term, yet I would argue you keep dishing out the same
> references without really considering the facts. Tell me why you think
> just changing the air filter (not the complete air intake

OH Fer Crying out loud! I've told you no less than six times!!!
Yes that term is perfectly applicable here. You are blowing smoke up
everyone's ass on this issue, and somehow you expect no one will call you on
your BULL****!

I logged every single fuel fill up and all maintenance (all done by me)
75,000 miles on a new car, both before and after a simple air filter element
change in the stock air box, with ZERO other changes.

Before air filter element change 7~25,000 miles with a very consistent 24.5
mile per gallon fuel mileage.
After air filter element change 25,000~75,000 miles with a very consistent
26.5 mile per gallon fuel mileage.

All NORMAL everyday mixed highway / surface street commuter miles! Near
ZERO WOT!












> system) can effect fuel mileage. Two of your three references were ads, so
> you should view them with suspicious. All three were concerned with WOT
> performance, not normal everyday driving. Trying to predict changes in gas
> mileage based on WOT performance tests is risky at best.
>
>> I've posted three different links to documented dyno tuning of new FORD
>> cars with simple new air intake systems, that exceed the PCM's ability to
>> properly adjust the air fuel ratio without changing the programming.
>> There are many many more links showing the same. If indeed these peoples
>> information (dyno charts with A/F ratios) indicating a filter changing
>> DOES cause the PCM to run the air fuel ratio TOO LEAN, is held up against
>> your undocumented insistences that the PCM can maintain the proper A/F
>> ratio, seems like you are wrong.
>
> The first reference you cite, really just an ad
> ,http://www.allfordmustangs.com/revie...hp/product/394 was
> ridiculous. I have repeatedly pointed out that it is inconsistent.
>
> Point 1 - They are measuring performance at WOT. The vehicle runs open
> loop at WOT, so the PCM is not adjusting the A/F based on feedback at that
> point. For real world situations, this is handled by the long term fuel
> trim. However, in order to learn the long term fuel trim, you have to
> actually complete a drive cycle.
>
> Point 2 - I doubt if what they say is even true (or at least not in sense
> that you interpret it). The ad provided no numbers, it just made a BS
> statement - "Even when replacing the air filter ONLY to a higher flow
> assembly, the air/fuel ratio leans out at an alarming rate." What is the
> air filter assembly? Just the actual filter element, or everything in
> front of the throttle body? What is an alarming rate? How can "replacing
> the air filter assembly ONLY to a higher flow assembly" lean out the A/F
> ratio at an "alarming rate" when in the same article they claim that
> replacing the air filter assembly won't result in a mixture "lean enough
> to cause engine durability concerns." If there are no durability concerns
> (at WOT by the way) what the heck is "alarming."
>
> Point 3 - Mostly the ad is talking about a complete intake system
> replacement, including the MAF. Certainly if you start screwing around
> with the MAF you may need to retune the PCM. I never made any claims about
> what happens when you do things like that. I am only talking about air
> filters in the OE intake assembly. Once you start screwing with the other
> components (particularly the MAF), all bets are off.
>
> Your second reference was another thinly disguised ad
> http://musclecarnews.tenmagazines.co...ticle&aid=3684 :
>
> Point 1 - There are no charts that say anything about FUEL ECONOMY.
>
> Point 2 - There are no charts showing that changing the air filter ALONE
> will cause the engine to run to lean. And although the charts do show
> changes in A/F ratio when the COMPLETE AIR FILTER ASSEMBLY is changed
> (again the charts are showing only WOT operation), I don't see anything
> alarming. Without data at part throttle operation and after the PCM has
> learned the long term fuel trim, I can't see where the information
> presented can be used to say anything about the effect changing the air
> filter has on fuel economy.
>
> Point 3 - I suspect they did not bother to complete a drive cycle in
> between the tests. Unless you compete a drive cycle, the PCM does not have
> a chance to learn new long term fuel trim parameters. Since they are
> measuring things at WOT (i.e., not in feedback mode), you need to complete
> a drive cycle to make sure the PCM has learned the correct long term fuel
> trim so that the A/F ratio will be corrected for open loop operation.
>
> Your third reference
> http://www.edmunds.com/insideline/do...ticleId=118839 was dealing
> with performance, not fuel economy. I agree that a restricted air filter
> can reduce maximum power. So, I have no problems with this article.
>
> Ed
>