This is my first mini it's a 2002 mini cooper 1.6 non-s and I have noticed that I'm not getting the right mpg and also I noticed that it's kinda sluggish between 2500 and 3500 or so I need to know if there is anything that I can do to fix this issue any input will be much appreciated.

Thank you guys.

what mpg you getting ? and they are not all that fast 1.6 16v tbh cause its a heavy car.

If you've got aircon fitted then make sure its switched off, as it used to sap loads of power in the low revs on earlier cars.
Other than that - just try using high octane fuel -97-99 ron for a couple of tankfuls & see if that helps.

You dont say what your actual mpg is, but as long as its over say 28ish on the urban cycle & say 35 at a constant 55mph then your doing ok.

Hi

If you are shore it is not right
Get you car plugged in to a diagnostic tool see if there are any faults codes not all code bring on an EML light.
You my find if your pre cat O2 sensor is playing up or shot this sensor does not bring on the EML light.
If this sensor is shot it can cause rough running bad idle and bad fuel consumption
Hope this helps

Another thing to check if you have not done in a bit is new plugs, belt, airfilter and maybe fresh set plug wires.