I have an earlier Ford 6.9L IDI diesel (with a Banks turbo kit the last 18 years) and recently switched to the bigger FL-1995 filter from the smaller FL-784, which is spec'ed for my older engine. I've had the truck since it was a year old (it's an '86) and have always used the FL-784 till now. I noticed something interesting on the Wix site about these filters... at least on the Wix brand. The Wix FL-1995 equivalent (Wix 51734)had a nominal micron rating of 19 with a Beta ratio of 2/20=10/30 while the 784 equivalent (Wix 51742) had a nominal micron rating of 25 and a beta ratio of 2/20=24/44. I suspect any filter brand will (or should) follow the same trend because the Powerstroke has the HEUI injection and it's more susceptible to dirty oil than the old IDI engines were. Both engines have an internal bypass, BTW. It took me ten years to figure this out, sheesh! My truck has only 120K miles, so with the better filter, I figure they’ll roll me into the grave in my old Ford with the original engine intact. I'd sure like to be able to determine the filtration specs on the Motorcraft filters! BTW, my Wal Mart just got rid of all the MC filters (again). Lucky I just switched to Wix.