I'm think about remapping my 318 sport 2010 plate is this worth doing. Some one said it's can infect injectos is this true cheers 

Not true, i had a downpipe and uprated intercooler for my 135i and got an extra 80BHP and 108 lbs. Injectors wont be affected.

Morning Lee

Is your car 318 petrol or diesel ? If petrol does your car have the inline 4 cylinder or 3 cylinder ? 

As a rule of thumb a forced injection engine (like Nick's 135 which has a twin turbo system) will respond better to remapping than normally aspirated engines. Not sure about the injector comment, but in the real world injectors are chosen for the fuel delivered at a given pressure and it's spray pattern (atomization)  Quantity is controlled by duration. So even a forced induction engine will reach a ceiling for power delivery unless the fuel delivery system is uprated (fuel pump injectors etc)

If your engine is 318i four cylinder normally aspirated then remapping wil give fairly small gains. If your engine  is 3 cy;inder turbo then gains can be quite healthy. If the engine is 318d then you will see again a significant in crease from a remap.

With all tuning it will reach a point of £ spent vs Power gained where it may be cheaper to buy a model with the power you want.

Dave