Power Steering Fluid Additives: what Claude and GPT would buy

Two AI models chose on their own, with no web access. Nobody tested these products: this is what each one says, and how to check it.

They disagree: Claude chooses BlueDevil and GPT chooses LUBEGARD

In Automotive, Claude and GPT choose the same brand in 60 of 112 categories.

Claude Opus 5.5 · October 27, 2026

BlueDevil Power Steering Stop Leak (line)

A seal-conditioning stop-leak for slow rack and pump seeps that you can add without draining the system.

Not for: Cars with electric power steering, leaking hoses or fittings, or a rack that is visibly dripping.

GPT 6.1 Sol · November 11, 2026

LUBEGARD Power Steering Fluid Protectant (line)

Helps reduce hydraulic steering noise and friction; I would use it only when the vehicle manufacturer permits additives.

Not for: Electric power steering, incompatible fluid specifications, or repairing mechanical failures.

Lucas Oil Power Steering Stop Leak (line)

A thick conditioner commonly used to quiet a whining pump while sealing minor seeps.

Not for: Systems that call for a thin dedicated fluid such as CHF-type or OEM-specific power steering fluid.

Does the car even use fluid?. Check whether the steering is hydraulic or electric. Many newer cars use electric power steering and have no reservoir. Buying fluid additives for a fluid-free system is a common mistake.
Fluid type compatibility. Match what your system specifies: ATF, a universal PSF, or an OEM-specific or CHF-type fluid. Some European and Japanese systems react badly to generic fluids and thick additives.
Leak location. Additives help hardened internal seals. Replace leaking hoses, crimps and O-ring fittings instead. Rubber conditioners can't seal a hole in a hose.
Whine diagnosis. Rule out low fluid, air in the system and a clogged reservoir screen first. These cause most pump noise and are cheap to fix.

Shops seen in search results on November 5, 2026. A shop missing here may sell it too. Nothing was checked by a person.