I've had my fastback for a few months now and despite a good tune up I am disappointed with the fuel consumption.
The motor does not blow any blue smoke.
It runs twin solex carbs.
I am told that as the carbs get old, the internal parts wear out and they will use more fuel.
I am open to suggestions. I do not intend on keeping this car standard so even changing to a singe carb setup is an option, I never use the boot anyway.

The distributor is the heartbeat of the engine.
The vacuum advance is there solely for economy and is prone to dying from old age.
It can be tested easily by putting the vacuum line in your mouth and watching the distributor breaker plate move.
Put your tongue over the end and it should stay in place.
009 distributors do not have a vacuum advance fitted, hence the lack of economy. Good for going flat out though!

Veedubunlimited are now advertising a genuine(?) Bosch distributor rather than the lower quality repro's at about US$169.
I am rather keen to find out what they are like.
With a US order pending I might just get one.

^^^ good advice. Go the vac dissy and get an experienced VW shop to give the engine a service and tune.

Also, is your speedo accurate?

A client of mine with a freshly rebuilt engine is finally seeing 10.8 litres/100km with thier stock 2.0 litre Kombi, so you could get better in your type 3 if the engine was in good nick and tuned properly.

You say you're disappointed, but what kind of fuel usage are you actually getting? The late Type 3s are pretty heavy and will use more fuel around town than a bug, but should do better on the highway. Mine did about 12 or 13 litres/100km in town and better than 10 litres/100km on a longer trip. They are old cars and fairly heavy for their engine size so if you are used to the fuel consumption of modern 4 cylinder cars you will be disappointed!

Also check you speedo aginst those 5km markers on the freeway

Mine have been up to 20% short

But around town I would be surprised if you were getting better than 12-13L per 100kms

Dual webers or Dels would be a better op[tion than a single

our 2010 Toyota SR5 V6 hilux uses about 11l per 100 and towing a trailer with a beetle on it about 16L/ 100
It about the same as our 1916 beetle uses , thats why its cheaper to tow it

you could fit a subaru motor, on Hwy about 7L/100 @ ABOUT 3000RPM with plenty power to spare as they rev to 7000rpm no prob.

Thanks all. From my calc's, I am getting around 12-13l/100k. I see that I cannot expect too much as yes, they are heavy, but having owned a 73 BMW30.si I somehow thought this would be cheaper to run.

By the way, if you have money to burn on parts, a 3.0si is a beautiful car.

My mate had a 3.0

Best beemer in my books
But yes - reckon they would be a bitch to get parts for

good fuel economy whats that ha ha , 2110 in a lowlight dc with tray full of bay parts dual 44's big heads cam think i did 180kms and used 35ltrs doesnt help sitting on 110-130km/h cruising along

Have you tested the compression?