Poor mpg

[old man Logan]

Good morning all,got a 1998 w210 e280 m112 engine,my mpg has suddenly dipped also getting a whiff of petroleum when I stop , crankcase sensor? Or shall I disconnect the battery and reset?was getting around 22 now 17

 

[malcolm E53 AMG]

Morning,
Is the engine getting up to temperature, ie does the thermostat open and close as it should and what is the operating temperature at the 6 mile point? If that checks out the engine is over fuelling in some way so check air filters MAF etc without knowing how the engine is running it’s difficult to assess it could be down to wear on the injectors

 

[old man Logan]

Cheers,she gets up to temp a smidge over 80°, engine smooth as always, gearbox changes up fine , doesn't appear to drive any different just mpg crap ,have ordered a crankcase sensor,next was a MAF sensor as it looks like that's the original still fitted on the old girl

 

[old man Logan]

Would a touch of injection cleaner help ?

 

[Botus]

if that old could well have rubber in hoses, seals, pumps, etc. that can't cope with ethanol - there is a reason they brought it in - to make you buy new stuff

and at 10% filth it must introduce a 6% increase in fuel consumption - but few stuff so little loss - many see 20% at they engineered the fuel to be way more usless than just the percentage of rot filth they put in there now....