What is the difference between Dot3 and Dot4 Brake Fluid?

One of the main differences between Dot 3 and Dot 4 is their boiling points. Dot 4 will have a higher boiling point as compared to Dot 3. There are some people who have tried the compatibility of Dot 3 and Dot 4, and they are compatible. You just need to think about the boiling point if this is going to be important.

Remember that intense heat will have the ability to vaporize the brake fluid, especially if you are used to using Dot 4, but you are now using Dot 3. You may feel that the brakes feel a bit spongy. They also have some differences with their overall composition. Dot 3 is only made out of glycol ether while Dot 4 is made out of glycol ether and also borate ester.