Brake Rotors: Solid, Vented, Drilled or Slotted - which ones are right for me?
Tuesday, 9 July 2019
So, your vehicle is due for a brake pad and rotor replacement.
The question is, how do you know which style of brake rotor is right for your vehicle and driving style?
Do you just commute to and from work, or are you planning on towing heavy loads or doing the occasional track day?
The amount of different rotor options out there can leave your head ‘spinning’ (because the rotors spin, geddit?).
The first option is the solid brake rotor.
This is a simple design and, as the name suggests, is a solid design usually made from iron.
These are the cheapest rotors you can buy but are less effective at dissipating the heat caused from multiple hard stops, so are only suitable for the inner city runaround.
Solid rotors are fitted to the rear of some vehicles as the rear brakes only account for roughly 30% of the combined braking effort.
The next, and most common form of brake rotor, is the vented rotor.
These are a similar design to the solid rotor, apart from they have cooling veins located between the two surfaces.
When brake pads are pushed during multiple hard stops, they release gases which prevent proper contact with the disc rotor.
This is the main culprit of the phenomenon known as ‘brake fade '.
The veins in vented rotors allow the hot gases to dissipate, increasing the service life of the rotors and brake pads.
Most modern cars will have these rotors on the front of the vehicle with solid rotors on the rear, and this will work perfectly fine for your daily commute and even towing smaller loads (a box trailer, jetski etc) where there is additional weight to bring to a stop.
The next step up from the vented rotor is the drilled rotor.
Drilled rotors are designed to dissipate the gases created by constant hard stops using a number of small holes drilled into the faces of vented rotors.
While this is good to reduce brake fade, drilled rotors can be structurally compromised due to the weakening of the faces.
If you’re only driving on the street and towing infrequently this isn’t a problem, but if you are tracking your car and pushing the brakes as hard as they can go, it might be worth moving onto the next style of rotors.
These are known as slotted or grooved rotors.
Again, these are based on vented rotors but instead of drilling holes, diagonal slots are machined into the faces.
These slots, or grooves, do not go the whole way through the rotor, so they do not affect the structural integrity like drilling does.
They provide the same function of removing the gases produced under hard braking, and the slots also ‘clean’ the face of the pad, removing any built-up brake dust.
The downside to these style of rotors is the increased pad wear. The edges of the slots increase friction, which in turn increases the wear on the brake pads.
So which rotors are right for your vehicle and driving style?
For 90% of the population, and depending on what your vehicle was fitted with from factory, standard vented and solid rotors will be more than up to the task of what you can throw at them.
If you're planning on towing frequently, live in a mountainous area where your brakes build up heat on the descent, or like to take your pride and joy to the track and pretend you’re a world class racing driver, it may be worth upgrading your rotors to a drilled or slotted set.
It might also be worth looking at different brake pad material to ensure your brakes bring you to a halt consistently and safely, time after time.
Finding a passion for cars from a young age, Joel carried out work experience as a mechanic whilst at school before starting an apprenticeship after finishing year 12.
After almost 10 years on the tools and in customer service, he moved into the IT realm as a Data Analyst and In-House mechanic at AutoGuru.