[FG NA tuning help]

Hi all,

Very new to the tuning side of things and would love some help starting out.

Any help pointing me in the right direction would be awesome.

Not after huge power gains but better fuel economy would be awesome.

Have a NA FG I6 with pacemakers, high flow cat with 2.5inch piping through with standard mufflers. Air intake is just a SS growler intake.

[fixing speedometer under reading]

28 minutes ago, Puffwagon said:

And it changed the speedo readout?

Yeah, speedo is no longer out for me

[fixing speedometer under reading]

18 minutes ago, Puffwagon said:

What did you change?

Changed Tyre_Size by doing minus 5% off the total value

[fixing speedometer under reading]

Thank you all for your info! It was very helpful and have figured it out!

[fixing speedometer under reading]

I'm running a larger tire size on my 2010 FG mk1 and have found that the speedo is reading 100 when i'm actually doing 105, i've noticed it is also at other speeds as well. 
I've worked out that the difference in rolling diameter is 5.1% or 32mm larger than the stock sizing.
Would anyone be able to help with with fixing the reading issues on the speedometer or point me in the right direction?
Many thanks.