It's not that your fuel is thicker, it's that it's full of crap that causes wear. I do not know enough about the pump to tell you where to look, but common sense to me says if the wmo oil you are running in that precision high tolerance pump is clean enough not cause any wear, then why don't you pour it into your engine and reuse it? If pouring wmo into your engine gives you a uneasy feeling, then I would have the same uneasy feeling putting it in my fuel system.
Lots of people run wmo oil. They know it wears the pump out prematurely and accept that as part of the game of saving money. As high as fuel is now, you could run wmo and put a rebuilt pump on it every few years for $800-$1000 and still come out ahead.
I recommend you let the subject rest and not advertise what you are doing so much. Our country is changing, and they have been going after the diesel tuners and other racers. You know the next thing will probably be people skipping out on the road tax. More than likely if burning wmo becomes wildly popular, they will probably make rules on what the garages do with their wmo and your supply may dry up. Stealth is going to be your friend in this subject.
