I have recently bought a juicer and have been testing which pears are best for juicing.
2 Conference pears weighing 480g provided 300mL of juice: 0.62mL/g at a price of £2.40/L
The juice was sweet, creamy but not powdery and gave an olive green colour.
2 Comice pears weighing 510g provided 375mL of juice: 0.73mL/g at a price of £2.36/L
The juice was thick with small bits, pulpy, sweet and a muddy brown colour.
2 Williams pears weighing 285g provided 125mL of juice: 0.43mL/g at a price of £3.47/L
Very thick juice almost like a smoothy, strong pear flavor with a creamy brown colour.
I would suggest using Comice pears for juice as they provided the most juuice per gram although Conference pears are probably just as good as they are usually a bit cheaper so the price per mL is very similar.