I did have a 1998 T4 2.5 manual petrol Transporter, Racemag, but not in syncro
Had around 700 kgs permanently in it and fuel consumption was around 10l/100km urban and hwy combined
Generally speaking a syncro would account for .5 to 1 litre extra per hundred kays
Sold it at 400,000 ks and it's since done another 40,000 without any dramas
It was originally on lpg but consumption was around 13.5l/100ks and with the dramas I had then I ditched it and went back to petrol


M