Look at these :
http://www-static.shell.com/static/gbr/downloads/euroshell/shell_fuelsave_diesel_leaflet.pdf
(Not sure there is much difference in the soot build up on the Injectors in the first pictures)
and also look at this :
http://www-static.shell.com/static/gbr/downloads/euroshell/shell_fuelsave_diesel_brochure.pdf
Paul
http://www-static.shell.com/static/gbr/downloads/euroshell/shell_fuelsave_diesel_leaflet.pdf
(Not sure there is much difference in the soot build up on the Injectors in the first pictures)
and also look at this :
http://www-static.shell.com/static/gbr/downloads/euroshell/shell_fuelsave_diesel_brochure.pdf
Paul