air filter vs fuel economy - controlled test results

[ivymike]

regarding thread71-214125

A government study has (FINALLY) shown that what they've been saying about filters and fuel economy has been wrong for 20 years, if it was ever right.

http://www.fueleconomy.gov/feg/pdfs/Air_Filter_Effects_02_26_2009.pdf

"Results show that clogging the air filter has no significant effect on the fuel economy of the newer vehicles (all fuel injected with closed-loop control and one equipped with MDS). The engine control systems were able to maintain the desired AFR regardless of intake restrictions, and therefore fuel consumption was not increased. The carbureted engine did show a decrease in fuel economy with increasing restriction. However, the level of restriction required to cause a substantial (10–15%) decrease in fuel economy (such as that cited in the literature3,4) was so severe that the vehicle was almost undrivable. Acceleration performance on all vehicles was improved with a clean air filter."

 

[SomptingGuy]

I guess if the car is auto, a (throttle linkage based) kick down trigger could be tripped more often if the lack of power is compensated for by more aggressive use of the throttle pedal.

- Steve

 

[dicer]

When these type of disscussions have come up in various places, I have always compaired a plugged airfilter on a newer electronically controlled engine, is like going up the highest mountain pass you could find. The controls are going to maintain the correct mixture, so a plugged airfilter should actually give you better gas milage, with of course a loss of power. Because with the loss of air, there will also be a loss of fuel supplied.

 

[yurinovich]

thx for the link ,very interesting

 

[apsix]

I've just returned to this thread.

Thanks Pat, your suggestion is noted, but rejected.

 

[patprimmer]

I wasn't asking your permission or aproval.

Regards
Pat
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