Fuel use correction factors

Hi,

Wonder if anyone can enlighten me about using the Fuel Use Correction Factors.  Let's say my ECU says my average fuel economy is 8 mpg since the last fill up.  When I fill up, the fuel economy calculates to only 7.6 mpg.  Do I set the Fuel use correction factor to -5% or +5%.  My head tells me -5% but on my other ECU reader requires a positive correction factor for the exact same situation.

Another question on Trip Fuel Economy.  Let's say you have a two stop trip, that will require shutting off the engine and tablet at each stop.  Does the adapter pull the data for Ave Fuel economy from the ECU for the first travel day and include it into the calculations for the second travel day?

Thanks,
Steve

Finally got the rig back on the road and figured out how to use the Fuel Correction factors.  I found that in order to get my Trip Average MPG to read close to my hand calculated mpg, I had to add a correction factor of +5%.  Yes, I am a nerd!  :)