Hey all! So I have two idi trucks: a 1991 f250 7.3 N/A (soon to be turbo) E4OD 4X4 and a 1987 F350 6.9 t19 4X4. I know that back in the day the diesel had sulfur in it and that helped lube the fuel system. I have been told by some older guys that I should either get sulfur substitute or put ATF in my fuel for the long jevity and efficiency of my motors. This makes sense because I use lead substitute in my gas tractor from the 50’s but some more opinions never hurt. So what do you guys say on that?