Worked on both, much preferred products to crude.
In the distant past the difference for engineers was
Motor or
Steam
I think most of the big ones are motor now,
Back in my day even the product tankers had full size boilers to run pumps and or TA for pumps.
My son just worked on a couple as eng cadet.
Motor ship but still has full steam plant for cargos, no steam time cause it’s a motor ship.
The smaller one runs LNG so both were interesting
Trouble I found with the big ones they go from nowhere to nowhere and take a long time getting there.
Other differences crude oil washing but it’s a deck guy thing.
They all have IG, though some of the products ones I was on were open load.
Yes a long time ago.
Back in my day most US tankers were steam. Not sure now, I would think most of the old T2 are long gone.
Segregation of ballast and Double Hull required.