Mk6 Fiesta Exhaust question

[Kieran Sliwowski]

Hello everyone,

I have recently installed a hornet exhaust system to my 2007 fiesta 1.25 (not because I'm a boy racer I just like the sound of it😂) and I have noticed a drop in fuel economy of around 4 mpg.

I have found its a bit worse when cold, improving slightly once warmed up. The drop in mpg is also around 4 on motorway cruising too.

Everywhere I have looked is saying to me that changing an exhaust should have no/little effect on mpg for a car and in some cases it actually improves it.

All I have done is put the system on, nothing else has been done as of yet.

Is there anything you think this could be? If you need me to explain anything better just ask what you need to know👍

Cheers for the help

Kieran