Hi Ausias!
Yes, the 5th gear swap was pretty helpful in improving my FE at reasonable speeds on long trips. There are many options for the gear ratio on that 5th gear... I didn't go too tall, only .681 but of course there are also .622 and .588 available. There is even a kit now that can add a 6th gear to the standard 5-speed manual transmission (cheaper than doing a complete change to a standard 6-speed... ). It is something that I may consider doing because then I can have a slightly tall 5th speed and a very tall 6th for the long flat drives.
As described in my Helga description, I've also replaced the stock injector nozzles with larger T4 nozzles and had a little bit of a tune to adjust for the larger nozzles... this has helped improve the 'driving enjoyment' quite a bit while also giving Helga the extra grunt that she needs to shift much sooner (usually around 1500rpm or so). So yes, originally I started with the 90hp 1.9L TDI, but now I think it is a little more than that.
One of my (non-FE related) tasks in preparation for this long trip was to replace the driver's side axle... it was making a bit of a grinding noise possibly related to the bolts being loose after some service... one of the reasons I prefer to do my own work when I can. So while I had the front struts out anyway, I removed the axle. Here is the missing appendage:
Can't help but think of the Boston Marathon victims when looking at Helga without the axle. Thankfully not as traumatic.
I got a brand new axle.
The inner CV joint was not pre-greased; the little tube in between the two axles is the grease. Unfortunately, I made a mistake when greasing up the joint... I rotated the outside of the joint so I could grease the ball bearings but I went too far... the whole CV joint came apart and the ball bearings popped out. It took one day, two buckets of sweat, and three languages of swearing to get everything back together again, made doubly difficult because everything was covered in grease. Now that it is finally all back together again, I'm fairly certain the ball bearings are well greased.
Pics of it all assembled next time.
Earlier this week, I worked some more on the replacement exhaust pipe. Here is a comparison shot between the old muffler and the new pipe.
I welded together 2 18" extensions plus a 45 degree tip and also welded on a hanger. Then did some grinding to hide my mistakes and painted. Came out about half-way decent, plus it'll be under the car anyway. Should be able to get it fully installed this weekend.
Now that the hardest parts are done, I'll be finishing up the rest tomorrow (Saturday). Exhaust, oil change, spats, and probably another attempt at an axle-back under-tray (as noted before, last year's attempt failed pretty quick, but I think I have some ideas). As well, a triple (or more) check on the important nuts and bolts that hold the suspension together.
Monday, I'll bring Helga in to get an alignment done, just to ensure that it's correct again after all that mucking around with the suspension.
Then Tuesday, we start the trek and I'll be trying to hit that magic 70mpg tank!