Hi Folks;

Air filters are placed on the intakes of engines to remove as much of the fine particulates in the incoming air as possible; i.e. all the stuff smaller than .005 or .006 inches. The big stuff is easy, most of it never gets anywhere near the filter anyway. Most of the after market filters are junk, unless they have more paper surface area than the stock filters, if you are trying to reduce the pressure drop across the filter. The screen type filters that you spray oil on may reduce the pressure drop very slightly but they sure do not filter out the small abrasive stuff in the air flow.

In any case the point is moot for all pressure charged engines. The manifold pressure sensor is downstream of the filter so the waste gate just adjusts slightly to compensate for filter drop, giving what ever manifold pressure is asked for by the throttle position and other inputs. To take any advantage of a zero pressure drop air filter you would have to change the computer and/or waste gate settings, not easy to do in a Volvo.

If someone sold a bigger intake box and a bigger paper filter and there was room under the hood for them, I might consider installing them. Until then, of all the Volvo components which need work/modification I would list the air intake system at about # 973.

CLEAN AIR AND CLEAN OIL ARE MANDATORY FOR ENGINE LONGEVITY.

All the best.

Robert A. Froebel