Oil Filters

More for the brains trust.
Oil & filter change time.
I just watched a bloke fill his CAT oil filter with new oil before he screwed it back on.
Then he proceeded to put the rest of the oil charge in via the filler.
I have never "pre-filled" any oil filter before.
Just wacked it in, whatever the charge is meant to be, check on the dipstick before starting and again a few minutes after running
Is his method better/worse, right/wrong?
Enquiring minds etc.
Thanks in advance

I thought you always had to pre-filled to ensure no air locks…. Just doing what I was told.

Always prefill

I always pre fill filters, as it saves that amount of oil that the filter has to prime, meaning less/minimal time the engine is running without pressurised lubrication. 

I always pre-fill where possible.

I was told that if you do not pre-fill, the bearings etc. are running without oil until the oil pump fills all the galleries.

Funny Cat used to specify DO NOT fill the filters in their engine manuals.
Personally the oil in the system is enough for a start and idle with less chance of junk going into the engine.

Blackduck that would be because Cat sell you new engine kits more often

A bit cheeky, Cobba.

Well think of older units with horizontal filter housings and elements, not spin-ons. No chance of filling those and they survived quite well.