BXE Fuel Economy

HI All

I have just replaced the camshaft on my 1.9 BXE 2006. Before i removed the cam i checked the torque value with my diagnostic and it was at -3.5. I did this as i have been reading up on various sites about fuel economy and the need for this setting to be correct after timing belt replacement. I did the timing belt and water pump in May 2017 so had no plans to replace the belt when i did the camshaft. New cam fitted ok timing belt refitted using all correct locking tools and the car started fine. I rechecked with the diagnostic and my torque value is now -0.5. I also reset the injector backlash when i did the cam but i have a feeling i may have set this too slack. I had trawled the net for a setting for the back lash and got 225degrees. I have since found that this should be 180degrees. Before the cam failed i was easily getting high forties and if driven steady early fifties mpg but now it seems to be returning mid forties. 

So what is the correct torque value for this engine? i have read anywhere between -3 to +3 is ok but there must be an optimum setting. Also would the PD backlash sett at 225 give any issues.

Thanks in advance!