The ECU controls your injectors as a set. So if they are imbalanced at all, you will have some cylinders that are flowing slightly rich and some flowing slightly lean. The percentages are how closely the injectors are flow matched to one another. The closer that the injectors flow to one another, the more precise the entire fuel system will be which makes it more efficient. This improved efficiency manifests as better fuel mileage and a smoother engine.

We offer an advanced 1% flow-matching service which also includes documentation of the flow-results for each injector. This is $80 for the advanced flow matching. 

As far as which option is correct, the choice is entirely up to the customer based on their individual needs and budget.

*Please send us a message if you are interested in the 1% advanced flow-match BEFORE ORDERING*