The SDL just did this on the last tank. It lost about 50% of the available power when I got down to the last three gallons.

Funny thing about it was that it took about 100 miles of running, after the tank was filled for the power to completely return.

In fact, I can't be certain that it has fully returned because I typically measure its performance against a specific grade in CT. It should be able to hold 70 mph on the grade if it is providing the proper horsepower.

We'll see........

It's a strange deal, I'll say that for it. Can't be fuel filters, AFAIK, because they are not self-cleaning as the vehicle is driven.