501.14 conforms to the same DOT4 standard as most other fluids.
Not really. DOT4 is frankly an ancient standard, developed by the Yanks, and crucially, long before any specific requirements of ABS, and even more crucially, ESP / DSC systems.
So whilst VW501.14 may well 'meet' the DOT4 specification - crucially, 501.14 'exceeds' DOT4 by a massive margin. DOT4 specification fundamentally only refers to 'dry' boiling points and 'wet' boiling points - for brand new fluid from a sealed container. DOT4 makes no requirements of longevity of fluid (so there is no performance testing over its usage lifespan). Some DOT4 brews can go off exceedingly quickly. But above and beyond boiling point requirements, the DOT4 specification has absolutely no requirement on fluid viscosity - NONE! Modern ESP / DSC systems are highly reliant on very low viscosity brake fluids, and especially those from Conti Teves! The VW501.14 not only includes the requirement for a very low viscosity, it also includes an extended in-use performance quality requirement (very similar to the 650 hour extended drain interval for LongLife engine oils, compared to the 300 hour requirement for non LL engine oils).
The frequency of change is more important than the brand.
I won't disagree with that!
Though brand does matter . . .
I've used Mobil, ATE, Halfords own etc etc over the years - bugger all difference.
Mobil and ATE are top-spec brands. Halfords is now made by one of the top brands for them, though about 10 years ago and before, Halfrauds brake fluid was crap.
But there are some truly shyte DOT4 fluids from brands who ought to know better. I have frequently seen a supposedly quality brand brake fluid go off, and pour like honey or even treacle. Comma are particularly bad (as are all their oils
), as are the likes of Car Plan, Egol, and oddly many of the cheaper German brands. The best pure DOT4 only brake fluid will be one made from a Shell Oils formulation.
