I need a tire with less ply.
I need a tire with fewer ply.
Is "less" correct because ply is a singular noun? Or should it be "fewer" because it refers to a specific count of plied material? Or should "fewer plies" be used to reduce ambiguity?
A quick Google search seems to show that "fewer ply" is much more common. However, it could lead to confusion in the example below:
Continuing trend toward fewer ply tires is expected." -Technological trends in major American industries
It might seem that it refers to the number of tires as opposed to the having fewer plies, which seems to be the intention.
Another example could be toilet paper:
I normally use 3 ply, but now I am searching for a brand with (less/fewer) ply.