I had heard some interesting claims about how much the mpg would be improved by removing the EGR valve and changing the air filter so I thought Id measure before and after on my 2003 TD5 90. The mileage was noted after using at least three quarters of a tank, all driving on road,same local roads, no towing, no conscious change of driving style.
Before
Tank 1 31.03mpg
Tank 2 29.15 mpg
EGR Blanked
Tank3 29.09 mpg
Tank 4 30.05 mpg
Tank 5 29.9 mpg
Air filter changed to K&N
Tank 6 30.0 mpg
Not statistically valid of course but bugger all difference in my humble opinion. It does seem to pull more cleanly now though so worth doing.
Before
Tank 1 31.03mpg
Tank 2 29.15 mpg
EGR Blanked
Tank3 29.09 mpg
Tank 4 30.05 mpg
Tank 5 29.9 mpg
Air filter changed to K&N
Tank 6 30.0 mpg
Not statistically valid of course but bugger all difference in my humble opinion. It does seem to pull more cleanly now though so worth doing.