1.6 NA Giles vs non-Giles fuel economy comparison

[Giles@PerformanceDiesel]

thought i'd give my 2 cents in this equation

swapping the pump and injectors would be the best way for sure.
other things to consider are compression of both motors and the fact one motor is solid lifters and one hydraulic

i personnly don't like the Merc nozzless, they have a straight pre-stream of raw fuel in the middle of the atomized
spray pattern. it was developed just for the bad running Merc 5 cyl.  with a good DNOSD293 or 273 nozzle stock
nozzles it should run much better. i have tried these nozzles in my own car and they smoked all time.

sometimes there is just something different in MPG between engines and cars that no-one can put their finger on.

my own personal car is a 93 Passat with an AAZ, Giles pump  (of course). ported head, 2.5in exhaust. stock european
i/c'er. k&n filter. 135HP at the wheels. 1/4mi of 15.9sec.
this is my daily driver and i drive fast,  80-90mph all the time. lots of races and i get 43-45mpg, engine is pretty fresh
30,000mi on my own rebuild.

i see some people who get better mpg than others with the exact same car and equipment and no rhyme or reason
to say why he gets more than the next guy. would like to see the results after the complete swap

Giles

[Runt]

I'm going to throw a couple thoughts in here, but I fall into the group of people suspecting non-motor causes.
When were the wheels on the caddy last checked for balance?  I can't vouch for the truth of it, but I was taught years a go that an unbalanced wheel at 70mph could waste over 5hp. 
Also, you have mentioned that the alignment on the caddy is a little out.  I think you would be surprised by how much power is required to scrub one or more tires, even just a tiny bit.  Think about trying to maintain a steady speed through a corner, you have to roll into the throttle a little, right?  Consider that misalignment can be just like always trying to turn just a little bit.
I would think that either factor above could cost you at least a few mpg.