Since the ULSD switchover, diesel has cost roughly the same as premium gasoline in this part of the world. Pretty much all across the South. OP is in Houston, fuel cost is the same there as it is here. Diesel/Premium E10 is roughly 50¢ more per gallon than 87 E10. When fuel cost is roughly $2.45/gal for 87, that's a LOT of mpgs you have to squeeze out of that diesel to break even, not to mention actually save anything.

__________________
Current stable:
1995 E320 157K (Nancy)
1983 500SL 125K (SLoL)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Gone and wanting to forget:
1985 524TD 167K (TotalDumpster™) [Definitely NOT a Benz]