100+ Hypermiling / ecodriving tips & tactics for better mpg - EcoModder.com
65+ Vehicle modifications for better fuel economy - EcoModder.com
Five from each will get you past 18 mpg...lol
A scanguage does nothing special to the car. 10 SGiis hooked up to a car would make zero difference- it's how you use it. It gives you instant feedback, and that is what will help guide you.
Some like the challenge, some like the guidance, but mostly everyone agrees the instant feedback is the most crucial piece.
I know your challenge, when my Escort was ready to be sent away for good, I was driving a 4.6 2008 F150 (4x4, quad cab)- I only got 19.x to the tank with driving and zero feedback. You have already honed your skills at this point very well, with a more thirsty engine you have seen better. With feedback, further driving style improvements and potential modifications, you could see some very good performance (for the circumstance). Check out Diesel Dave, he puts a lot of hybrids to shame.