David,

All you have to fight with is the maximum allowed
axle weight for your vehicle and the loadindex of
your tires.
On my 2WD Vanagon (and all other European spec
Transporters, except those with reduces load capacity)
will carry 1100 kg front and 1300 kg rear, total
allowed weight is 2360 kg. The tires at least should
have the loadindex of 93:

205/70 R 14 93 N   (as an example)

Loadindex:   Speedindex:
90  600 kg   K  110 km/h
91  615 kg   L  120 km/h
92  630 kg   M  130 km/h
93  650 kg   N  140 km/h
94  670 kg   P  150 km/h
95  690 kg   Q  160 km/h
96  710 kg   R  170 km/h
97  730 kg   S  180 km/h
98  750 kg   T  190 km/h
99  775 kg   H  210 km/h
100 800 kg   V  240 km/h

Regards
Helmut