Some interesting data there, must have taken a long time to research and compile it. Important to note that alot of it only applies to trucks though, and isn't necessarily true for light passenger cars. I like the 50,000 mile true break in though, jeez I'm lucky to get 5000 from a set! Tyres do account for a lot of your economy, would be interesting to see the different results for size differences too. In my case, a car with 16" alloys as appose to my 17" will get around 5 MPG more overall, at least in the lab tests anyhow.
In a smaller lighter vehicle increasing speed may increase your economy. I read a report not so long ago where a car was tested at various speeds and it used less fuel at the higher cruising speed. That's why it's important to do your own experiments, you might be driving slow on purpose to save fuel when there's no need.
Ha well Draig or Ddraig if it follows a vowel, is Welsh for Dragon, as in the Red dragon (Draig coch) on our country's flag - Draigflag get it? Without sounding too patriotic, has to be one of the coolest flags in the World, I mean how many flags have fire breathing mythical creatures on them?