i always did it to my Powerstroke (FL-1995) but never did it to my gas motors because they all have had angled filters.

At work i do ~50 oil changes per day and the only ones i prime are 7.3L

 

I prime mine, its an 07 4 cylinder...It has a remote filter location that is straight up and down so why not. And when I had my mustang with the 3.8 engine (has an angled filter) I filled it half way so it wouldn't spill and atleast some oil would be in there right away on the first start. Reving the engine seems like a bad idea to whoever said that...something about no oil and higher rpm's... Dry starts are killer, I'm in MN and it's cold up here. The less dry starts the better, haven't had a bad dry start though since I switched to MOBIL 1. Just fill the filter and listen to the beautiful harmony not the scraping and scratching of your cylinder walls...Fill it up, your engine will thank you

 

I always prime mine. I realize that in 5 seconds the oil will be flowing freely, but since the filter is straight up and down on my 4.0, it is cheap insurance. I never knew about diesels needing it.

 

On a diesel it's the fuel filter. You don't want to get air into the injector pump, and between the injector pump and injectors. This is also why it takes
a long time to start a diesel if you run it out of fuel......

 

Ive always poured a little oil into the new filter before installling it, never had a problem.

 

Same here, I have always filled any filter that hangs down, usually fill it up, dab finger into the new oil, lube the gasket and tuck it aside for a min, usually most of the oil is absorbed into the filter media by the time I install it, fill the crank case and fire it up.

 

I fill the filter up. Its certainly not goona hurt anything and I'm not in a hurry