Engine oil flush yes or no ???

[amwphotos]

20mpg? That sounds ridiculous, it's not a Ferrari! If that's the best you can get something is surely wrong and needs checking. Pretty sure you don't drive everywhere in 1st gear!!

 

At this point deciding whether to use oil flush or not (I never have at 200,000 miles in my old megane diesel and it's sweet) and wondering about super petrol is the last of your worries!