bash - increase characters visible in diff -y columns -

is possible increase amount of characters visible per line, per column when running diff -y <fooa.txt> <foob.txt)? have files long names , unclear ones being compared when names truncated in columns.

ex. 8d14a361aefb7796de07e9ef4aa5d2f4 2014_141_1_1__studs_place_c | 77831755d1f1db1c726d0964c807b74b 2014_141_1_1__studs_place_c

from man diff:

   -w num  --width=num          output @ num (default 130) print columns.