if you are searching for economy, aerodynamics is the key. the stock intake is far less restrictive that the car can use. tweaks to the alda, and the timing of the IP, along with perfect balance on the injectors, and delivery valves will net you the most economy.
reducing weight in the car, perfecting the shifting, and getting a manual trans.
moon hubcaps, air dams, spoiler/wing...

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!