Roof bars are the "base" for dramatically increasing your car's carrying capacity. Whether it's a roof box, bike racks, skis, a kayak, or simply transporting bulky items, the right choice is crucial for safety, fuel economy, and ease of use.

Follow the 6 steps below to make the perfect purchase.

Step 1: Identify your car’s roof type (The most important step)

Not all roof bars fit all cars. The mounting system depends entirely on the roof your vehicle has. You need to identify which of the following categories you belong to:

1. Bare Roof (Normal Roof / Bare Roof)

The roof has absolutely nothing on it (neither rails nor holes).

How they are mounted: The bars use special "feet" (kit) that clamp onto the edge of the roof, between the door and the bodywork. They often have rubber pads to prevent the paint from getting scratched.

2. Raised Rails (Raised Rails)

The car has two parallel rails running lengthwise, which are raised above the roof (there is a gap underneath, and you can pass your hand through). Very common on SUVs and station wagons.

How they are mounted: The bars’ "feet" clamp around these rails. It is the easiest system to install.

3. Flush Rails (Flush Rails)

The car has parallel rails, but they are attached to the roof, with no gap underneath. They usually have a small groove on the outer or inner side.

How they are mounted: The feet are specially designed to "hug" the profile of that specific rail.

4. Fixpoints (Fixpoints)

The roof is smooth, but it has 4 (usually) specific mounting points, covered by plastic caps or flaps.

How they are mounted: The bars screw directly into these factory mounting points. It is a very stable system.

Step 2: Material and design selection (Aluminum vs Steel)

Once you find the mounting system, you need to choose the type of the bar itself. There are two main options:

1. Aluminum Bars 
These are the most modern and popular.

Pros:

Aerodynamic design: They have a wing-shaped profile (oval/wing shape), dramatically reducing noise (whistling) during travel.

Economy: Due to low air resistance, they consume less fuel.

Weight: They are lighter, so easier to install.

Appearance: More attractive and modern.

T-Track System: They feature a groove on the top (usually covered with rubber) that allows for very easy and quick installation of accessories (bike racks, ski racks) with special T-bolts.

Cons:

More expensive than steel bars.

2. Metal & Steel Bars 
The classic, traditional solution. They usually have a square cross-section and are covered with black plastic.

Pros:

Cost: Significantly cheaper.

Durability: Very sturdy (although the load capacity is often limited by the car roof and not by the bar).

Cons:

Noise: They produce a lot of noise at speeds above 80 km/h due to poor aerodynamics.

Consumption: They increase fuel consumption.

Rust: If the plastic gets scratched, the steel underneath can rust over time.

Accessory installation: Accessories (e.g. a bike rack) must be secured with clamps around the bar, which is more time-consuming.

Step 3: Choose shape and aerodynamics

The material does not determine the noise. The shape of the bar determines whether you will hear annoying "whistling" on the highway.

Square bars: The traditional shape (usually in steel, but also available in professional aluminum). They have poor aerodynamics, "hit" the air, and cause quite a bit of noise at speeds above 80-90 km/h.

Oval bars: A middle-ground, improved solution. They cut through the air better than square ones, but may leave a slight "hum" at higher speeds.

Aerodynamic (Wing shape / Wing): The top choice. Their profile resembles a drop or an airplane wing (thick in front, narrow at the back). They "slice" through the air, offering complete quiet during the trip and do not increase fuel consumption.

Step 4: Load Weight and Safety

Before you buy, you need to know two numbers:

Bar load capacity: How many kilos the manufacturer says the bar can support (usually 75kg or 100kg).

Car roof load capacity: How many kilos your car’s roof can support. This is stated in the car’s user manual.

Golden rule: The maximum load you can carry is the smaller of these two numbers, minus the weight of the bars themselves (about 5kg).

Example: If the bars can support 100kg but your roof can support 75kg, the maximum load (bars + luggage) is 75kg. If the bars weigh 5kg, you can place 70kg of luggage.

Security and Locks

Prefer bars that have integrated locks on the mounting feet. This prevents the theft of the bars (and anything secured on them) when the car is parked. Some cheap bars do not have locks or sell them as extra accessories.

Step 5: How will you use them? (Accessory Compatibility)

Think about what you will put on the bars.

Roof box: Most modern roof boxes have clamp systems ("jaws") that fit both square and aerodynamic aluminum bars. However, if the aluminum bar is very wide, check whether the roof box clamp opens wide enough.

Bike racks and ski racks:

If you have aluminum bars, the best solution is accessories that use the T-Track system. It is safer, visually cleaner, and faster.

If you have steel bars, you need accessories that are secured with U-type clamps (U-bolts).

Step 6: Installation and Use - Useful Tips

Read the instructions: Incorrect installation is dangerous. Follow the tightening torque specifications exactly (how tightly you tighten the bolts).

Check: After the first 50-100 km with load, stop and check whether the bolts remain tight. Do this periodically on long trips.

Load distribution: Place the heaviest items in the center of the bars and as low as possible (if they are inside a roof box). Secure them well.

Height: Always remember that your car is taller. Be careful in low-clearance garages, toll booths, and tree branches.

Removal: When you are not using the bars, remove them. Even aerodynamic bars increase fuel consumption and cause noise.