ALH fuel economy questions

Hi all, been checking through the forums here for a while but I can't see anything here that seems to relate exactly to my symptoms.
I just bought an 03 Jetta ALH with an automatic transmission and I drive mostly around town with the occasional short highway trip and I never get more than 650 km to a tank (I think this works out to roughly 30mpg if my calculations are correct). I've talked to others with similar cars who are getting around 900kms/tank (about 42mpg).
Here's what I've done so far:
- replaced the air and fuel filters (this car doesn't have a snow screen)
- cleaned the MAF sensor
- cleaned the intake manifold and EGR (it was pretty coked up)
- increased the air pressure in the tires to just below max
I have no fault codes and the car seems to have some power (I dan't really have a good point of reference for this though as my last car was an 87 Jetta TD!). The exhaust is fairly normal too, not much soot.
I have a VAG-COM cable and have had a look at the specified vs actual manifold pressures in VCDS and they seem to be pretty close to each other. Does this preclude any possible problems with the turbo/guide vane system or a potential plugged cat converter?
Another interesting thing is that on a recent long highway trip I got about 500kms on half a tank (about 47mpg or so) which is more consistant with the fuel economy I was expecting. This was on cruise control on the I5 doing about 110km/hr the whole time.
Am I correct in assuming that I should be seeing around at least 35-40mpg around town?
Any help would be greatly appreciated gentlemen!

Do you vent your tank (do a search for ventectomy) which helps you fill it to the rim so fuel just about spills out. Let the foam dissipate as you fill it slowly at the end.

Fill it up to FULL (to the rim) and drive it. I have an 02 manual and get about 1100km out of a tank at 100-120kmh full highway driving. Your automatic should be lower, but only by 100km or so.

Without filling it to FULL you never know how full your tank is because of all the foaming when filling.

My dad auto also gets that but his is a wagon. I use to get that when I frist got mine but then changed my drvining habits now I see 835km for 42.5L but mine is a manual

My 02 wagon averaged between 34 and 37mpg for the 1st 76k miles it was driven and then suddenly went to 40-42 overnight!!
After some back and forth on the forum I decided that my dreaded 01m torque converter had not been locking up; so with clutch slippage my mpg's were down.
Like I said, somehow the TC began functioning properly and my mileage went up. There was no work done to the car.
The lockup was also demonstrated by the end of the surging that the car had suffered from during the first 76k miles.
I am still averaging 40+ mpg with varied Vermont hill twisty country driving with the infrequent highway cruise.

I agree with checking fuel consumption starting with a full tank. And, the ventectomy is one way to do that.

But, if you don't want to do the ventectomy, you can full it to the rim using the vent release!

I have never done the Ventectomy on my car. I just fill until the nozzle kicks off. Then from there until it will hold no more, I vent by pressing on the vent release............ that's what it's for! Sure, it may take me a little longer and I may piss off a waiting customer.

Now, "city" driving really is tough on fuel economy of both manual and auto transmissions either diesel powered or gasoline powered.

My 5-speed manual has dropped in milage since I retired... more short run and "city" driving now. However, anytime I hit the road for a long trip the MPGs pick back up very good!