Why is my Focus 1.6tdci returning low MPG after fitting new DPF & EGR?

[Qaisser]

Hi

CAR: 2008 Mk2 Ford Focus 1.6tdci Zetec, 94k, FSH. 

ISSUE: Went into limp mode, diagnosed as DPF codes. 

PRIOR TO ISSUE: very good running order with full service from Ford and some reputable garages. Returned average 55mpg. 

DURING ISSUE: Ran car approx 800 miles in limp more without any problems other than the usual lack of power. Returned average 35mpg. 

ACTION: Finally got round to major service including (new) timing belt, water pump, full service, glow plugs, DPF, EGR and ECU & manual regen. Injector cleaner/fuel additive may have been added by the garage but not too sure. 

(BTW - the initial problem stemmed from failing glow plugs that got masked by the DPF codes. The DPF was absolutely fine but because the glow plugs weren't picked up in the codes the DPF got clogged and then ironically failed too). 

RESULT: after the works the car drives like a new car with max power. However the fuel consumption/mpg is still averaging the 35 mpg mark. 

THE QUESTION: WHY???

Why is fuel consumption bad after having fitted bed DPF, EGR  and glow plugs?

Any help, advice or guidance would help me stop me the scratching of my head especially having forked out £800 on parts and labour :/

Q

[tazzman600]

Hi m8. I think you'll get a better feedback if you post this in to the mk2 focus sections. Don't ask as I don't know how to move a post.

[Luke4efc]

6 hours ago, tazzman600 said:

Hi m8. I think you'll get a better feedback if you post this in to the mk2 focus sections. Don't ask as I don't know how to move a post.

Probably because you can't 😄😄. That being said I'm sure I've seen this posted before somewhere 🤔