Just from a point of accuracy, my understanding is that with the additives used - i.e. not the drug store stuff - Shimano mineral oil has a higher boiling point than DOT4 and only a slightly lower boiling point than DOT 5.1.
Technically DOT is hygroscopic and will absorb water (boiling point lowering) but I’ve never seen any test to suggest it’s a real issue with bikes.
Certainly the standardization, cost, and availability are all great talking points.
Mineral oil is probably still an easier product for the average home wrench to manage.
Pros and cons for sure but in the end maybe not a huge deal.
As I noted in the first look, Hayes chose to stay DOT as they said it helped with that very consistent, very light, lever action.
Jan. 30, 2020, 6:49 a.m. - Andrew Major
Just from a point of accuracy, my understanding is that with the additives used - i.e. not the drug store stuff - Shimano mineral oil has a higher boiling point than DOT4 and only a slightly lower boiling point than DOT 5.1. Technically DOT is hygroscopic and will absorb water (boiling point lowering) but I’ve never seen any test to suggest it’s a real issue with bikes. Certainly the standardization, cost, and availability are all great talking points. Mineral oil is probably still an easier product for the average home wrench to manage. Pros and cons for sure but in the end maybe not a huge deal. As I noted in the first look, Hayes chose to stay DOT as they said it helped with that very consistent, very light, lever action.