I get 21-23 around town and 25-29 on the highway with my 88 3.0ltr 300E. This is using 89 octane
fuel. I seldom run 91 octane but I do run a bottle of techroline once a year to keep the injectors clean.

__________________
Dave
88 300E 250K Sold
2000 C230K Totaled @104K
2003 ML320 156K Sold
2009 E350 4Matic Sport 46K Sold
2011 ML350 60K Sold
2014 GLK350 46k Sold
2012 GL450 67K
2016 E550 Cabriolet 48K