So, with a timing advance as much as possible and a chip, some people have seen 70 mpg+++ in normal driving.
In normal driving I mean just driving under 70 miles per hour with the cruise on.
The thing is, a chip is not the only performance (and therefore economy) mod you can make.
If you look at my mods, you'll see "Bosch 205's".
These are new injectors I installed.
The injectors on TDI's are different than on older VW diesel.
We have a 5 holes injector as the old diesel have 1 hole.
The mist produced by ours is finer, so injection is more precise.
A manual Passat (96-97)or Jetta TDI (97.5-99.5, old body) come with 184 micrometer size holes in the nozzle of the injector.
I changed those by the Bosch 205's complete injectors, which have 205 micrometer holes in the nozzle.
Stock it comes with 90 hp and 149 lb-ft at the wheel (European vehicules are measured at the wheel and not at the flyweel).
After putting the injectors I put TBVOD on the dyno and got 100 hp and 185 lb-ft of torque.
The injectors cost me 320CAD.
Good money vs performance increase.
I'll separate each item, so it's easier to read.