The DOT 5.1 Brake Fluid Review You Need to Read Before 2023

Brake fluid is an invaluable and indispensable component of a brake system. It is used in all hydraulics systems in all automobiles, motorcycles, etc. It is the main reason behind the stopping of your vehicle when you press the pedal. The type of brake fluid your vehicle uses determines the efficiency and power of the brake system. While a good and the appropriate brake fluid will enhance the responsiveness of a brake system, a bad and an unsuitable one will cause overheating, inadequate lubrication, and may equally affect transmission. That is why vehicle owners or drivers need to know the type of brake fluid their vehicle uses.

When it comes to brake fluids, there are different types. There is DOT 2, DOT 3, DOT 4, DOT 5.1, and the DOT 5. We shall be laying more emphasis on the DOT 5.1 brake fluid.

DOT 5.1 Brake Fluid

What is DOT 5.1 brake fluid?

DOT 5.1 brake fluid is glycol-based, just like the DOT 3 and DOT 4, but with a slightly higher dry boiling and wet boiling point. This type of fluid is widely used in automobiles and motorcycles.

DOT 5.1 brake fluids were developed due to the lack of acceptance of DOT 5, which is a silicon-based fluid. DOT 5 brake fluids are not compatible with vehicles that have ABS because it is immiscible with water. DOT 5.1 has similar chemical properties and structure of DOT 3 and DOT 4, and that's why it's widely used.

DOT 5.1 Brake Fluid Review

If you are looking for a quality brake fluid at an affordable price, Motul 5.1 is the best product that will match your description.

Motul is a major brand when it comes to manufacturing brake fluids for automobiles and motorcycles. The French company was founded in 1853 in New York City. They have been around long enough to know that there is no substitute for quality. For your vehicle's brake system to function at the optimum, it needs quality brake fluid. This brake fluid will ensure that your car responds to the stop command whenever you stop it. That is why they have come up with the Motul DOT 5.1 brake fluid. To ensure that your brake system is responsive and efficient as ever.

Motul 5.1 offers a high-quality performance of all hydraulic brake systems. Since it's a poly glycol-based fluid, it's compatible with all Anti-lock Brake Systems.


  • It has a wet boiling point of 180-degree Celsius and a dry boiling point of 260-degree celsius.
  • Motul DOT 5.1 is glycol-based, which makes them suitable for Anti-Lock Braking Systems.
  • Has a constant low viscosity.
  • This brake fluid has a low compressibility level, which is vital in ensuring stability and consistency in the brake system.

Pros & Cons of DOT 5.1 Brake Fluid


  • Motul DOT 5.1 is corrosion resistant. It does not corrode metal parts in the braking system.
  • Affordable.
  • You can mix it with other glycol-based brake fluids like DOT 3 and 4.
  • Can be used in ABS and Stability Control systems.
  • It is hygroscopic, which means it can absorb moisture.


  • It may damage the paint of your vehicle’s bodywork if it mistakenly spills.

Why is DOT 5.1 brake fluid the best?

DOT 5.1 brake fluids maintain low viscosity over a wide range of temperatures. This makes them compatible with cars that have an Anti-Lock Braking System (ABS) because this system uses small valves for quick activation.


This brake fluid has high dry and wet boiling points. Dry boiling point refers to a particular boiling point in a brake fluid without containing any moisture content. In other words, the dry boiling point is the original fluid content without water. Wet boiling point, on the other hand, refers to the boiling point of a fluid with moisture content. That is why most times, the wet boiling point is lower than that of the dry boiling point.

Being that DOT 5.1 brake fluids have high dry and wet boiling points, they can be subjected to high temperatures before vaporizing.

How To Change Your Brake Fluid

Start by identifying the type of brake fluid that your car uses. Once you are done with that, get a turkey baster. Get as much fluid as possible from the brake fluid container. Then, top up the reservoir with the new brake fluid to the appropriate level. Remember to dispose of the old brake fluid as it's no longer useful.

How To Check the Level of a Brake Fluid?

It's not so difficult to check the level of brake fluid. Firstly, you have to locate the brake fluid reservoir in the bonnet of your car. Once you have identified it, carefully remove the top of it. On the side of the brake fluid reservoir, you will see markers to indicate the level of your brake fluid. If it's below that marker, then it's an indication that you are low in fluid and that you need to top up. If otherwise, that means you still have sufficient brake fluid.

Once you are done checking, clean before replacing it, this is to prevent dirt from entering inside.

How To Determine the Type of Brake Fluid Your Vehicle Needs?

There are two types, generally - glycol-based and silicone-based brake fluids. Your vehicle's manufacturer manual will state the nature of brake fluid that is suitable for your car. Refer to it first before making any purchase.


DOT 5.1 Brake Fluid Review (FAQs)

Is DOT 5.1 brake fluid the best?

DOT 5.1 has the highest wet and dry boiling point, but that doesn’t mean it’s the best brake fluid out there. That’s because it has the same chemical properties as other mineral-based brake liquids with lesser wet and dry boiling points.

Is all DOT 5.1 brake fluid the same?

All DOT 5.1 brake fluids are the same. However, some manufacturers classify their aftermarket DOT 5.1 brake fluids as DOT 4 because they have the same boiling point. So in most cases, some DOT 4 brake fluids are DOT 5.1.

Is DOT 5.1 better than DOT 4?

DOT 5.1 has a higher boiling point when compared to DOT 4, but that doesn’t mean it’s superior to DOT 4.

Can I use DOT 5.1 instead of DOT 3?

Since they are glycol-based fluids, you can use DOT 5.1 in place for DOT 3. However, it's always better to adhere to your car manufacturer's manual for the recommended type of brake fluid.

What is the difference between DOT 5.1 and DOT 5 brake fluid?

DOT 5.1 is glycol-based and has a different wet and dry boiling point when compared to DOT 5 brake fluid. DOT 5.1 is widely used in the automotive industry. DOT 5 is silicone-based and is not commonly used because it's not mixable with water.

Does DOT 5.1 damage paint?

DOT 5.1, DOT 3, and DOT 4 are glycol-based fluids. Once they spill on automotive bodywork, it will damage the paint. That is one advantage silicone-based fluids like the DOT 5 have over glycol-based fluids.

Can you mix DOT 5 brake fluid with DOT 5.1 brake fluid?

The answer is a big NO! Like earlier explained, DOT 5 is silicone-based fluid, while DOT 5.1 is glycol-based fluid. This means that they are not compatible and can not be mixed. Mixing them will corrode the components of the braking system and will cause brake failures. However, you can mix DOT 5.1 with DOT 3 and DOT 4 without causing your brake system any harm.

Is Motul DOT 5.1 brake fluid good?

Motul DOT 5.1 brake fluid is an excellent and high-power brake fluid that ensures your hydraulics braking system is super responsive and working optimally. It is one of the best brake fluids you can get in the market.

What can affect the effectiveness of brake fluid?

When brake fluids begin to absorb too much moisture from the brake system's seal, it can lose its potency. When it does that, your brake system will be unresponsive. What you need is to change the fluid and replace it appropriately.

Can I change my vehicle's brake fluid twice a year?

It depends on your vehicle’s mileage or time. You will have to refer to your vehicle’s manual for confirmation.

Final Words & Recommendations

Brake fluids are beneficial and go a long way in determining the performance of your brake system. They essentially prevent brake failures and make you enjoy your driving experience. You can't stop your car without a brake fluid.


Motul has proven to be a company that users can rely upon. Having been in the automotive industry for over 100 years, the company has manufactured high-quality brake fluids that will maximize the efficiency of brake systems. Motul DOT 5.1 brake fluid is no different and one of those products from the French company that is worth your money.- Also you can check PENTOSIN BRAKE FLUID REVIEW.