[thackney]

Because those mod's would cost $1500-2500.00 depending on car make + labor.

Then if that capital outlay will not justify the fuel savings, then I suggest to you, it is not much of a crisis.

[TXBSAFH]

A friend of mine replaced his stock air filter with a k&n replacement in his diesel work truck. Just replacing that filter wiht a $50 after market replacement gave him an extra 2 miles per gallon. This truck runs 50000 miles a year.