I thought I would show a 1.9 XL size mounted tire comparison, because the specs given are not very accurate. Also threw in a couple 2.2s just for fun. Something like this would have helped me when buying. I don't have every XL 1.9 but hope this helps.
From Left to Right:
*Axial 1.9 Nitto Trail Grappler:
4.7 x 1.9 / 119.4mm x 48.2mm "this tire has little man syndrome"
*Proline 1.9 Super Swamper SX XL:
4.75 x 1.75 / 121mm x 44mm "seems accurate"
*Duratrax 1.9 Deep Woods:
4.6 x 1.6 / 117mm x 42mm "this tire is way bigger"
*JConcepts 1.9 Rupture:
4.92 x ? / 125mm x ? "width seems about 1.75"
*Proline 1.9 Super Swamper Bogger:
5.40 x 1.91 / 137mm x 49mm "seems accurate"
*Proline 2.2 Super Swamper SX:
5.40 x 2.05 / 137mm x 52mm "seems accurate"
*Proline 2.2 Chisel:
"Ugliest tire ever but the best tire ever made"
From Left to Right:
*Axial 1.9 Nitto Trail Grappler:
4.7 x 1.9 / 119.4mm x 48.2mm "this tire has little man syndrome"
*Proline 1.9 Super Swamper SX XL:
4.75 x 1.75 / 121mm x 44mm "seems accurate"
*Duratrax 1.9 Deep Woods:
4.6 x 1.6 / 117mm x 42mm "this tire is way bigger"
*JConcepts 1.9 Rupture:
4.92 x ? / 125mm x ? "width seems about 1.75"
*Proline 1.9 Super Swamper Bogger:
5.40 x 1.91 / 137mm x 49mm "seems accurate"
*Proline 2.2 Super Swamper SX:
5.40 x 2.05 / 137mm x 52mm "seems accurate"
*Proline 2.2 Chisel:
"Ugliest tire ever but the best tire ever made"