Roof Bars: Frequently Asked Questions
The most common questions we get about choosing, fitting and living with roof bars. If you can't find your answer here, contact our team — most enquiries get a same-day reply.
What are roof bars?
Roof bars (also called roof racks or load bars) are the foundation of any roof load-carrying system on a car. They sit across the roof, secured at the sides, and provide a strong platform onto which you can attach roof boxes, bike carriers, kayak carriers, ski racks, ladders or other loads. Without roof bars, your car has nowhere safe to mount any of these accessories.
Will roof bars fit my car?
Yes — every car on the road can take roof bars, but the type of bar and the way it attaches depends on your specific make, model and year. At Bars 4 Cars we use your registration to look up your vehicle in our fitment database and show you exactly the bars (plus foot pack and fitting kit if needed) that fit your car. We back this with our Guaranteed Fit promise: if they don't fit, we'll refund you including return postage.
How do I know what roof type my car has?
There are four common roof types: flush rails (rails sit flush to the roof with no visible gap), raised rails (chunky rails with a visible gap you can put your hand under), fix points (hidden mounting points under plastic covers), and bare roof / clamp (no rails — the bars clamp into the door frame). You don't need to know which one you have — enter your reg above and we'll tell you.
What's the difference between aluminium aero bars and steel square bars?
Aluminium aero bars (like the Thule WingBar Evo and Summit Premium) are lighter and have an aerodynamic profile that reduces wind noise and fuel consumption. Steel square bars (like the Thule SquareBar Evo and Summit Value) are heavier and noisier but more affordable and equally strong for carrying loads. If you only use roof bars occasionally, steel is great value. If you have bars on permanently, aluminium aero is the better long-term choice.
How much weight can roof bars carry?
Most roof bars are rated to carry up to 75kg dynamic load (i.e. while driving). Some heavy-duty bars (like the Thule ProBar Evo) can carry more. The actual limit for your car is set by your vehicle's roof load rating — always check your owner's handbook. Note that the bar weight rating and the vehicle's roof rating are different limits, and you must respect the lower of the two.
Do I need a separate foot pack and fitting kit?
It depends on the bar. Some bars (like the Thule WingBar Edge) have an integrated foot and need no separate parts. Most others — the Thule WingBar Evo, SquareBar Evo, ProBar Evo, SlideBar, and most Summit and Menabo bars — need a foot pack (the part that attaches to your roof type) and sometimes a fitting kit (vehicle-specific clips). When you enter your reg above, our system bundles the correct parts together for you so there's no guesswork.
Do roof bars affect fuel economy?
Yes, slightly. Empty aero bars typically add 1–3% to fuel consumption at motorway speed; empty square bars add 2–5%. A loaded roof box can add 10–20%. To minimise the impact: choose aero bars over square, remove the box when not in use, and drive smoothly. Removing roof bars between long trips is the best way to keep fuel costs down.
Are roof bars noisy?
All roof bars make some noise above 60mph. Aerodynamic aluminium bars are much quieter than square bars. Fitting the rubber T-track strip (supplied with most aero bars) further reduces noise when you're not carrying anything. If you regularly drive at high speed, an aero bar is well worth the extra cost.
Can I leave roof bars on the car permanently?
Yes, modern roof bars are designed to be left in place and are weatherproof. However, leaving them on increases fuel consumption and wind noise. Many customers fit them for the season they need them (summer holidays, ski trips) and remove them otherwise. Aluminium bars are particularly easy to live with permanently.
Will roof bars damage my car?
No — when correctly fitted, roof bars do not damage your car. They're engineered to clamp or attach using your vehicle's designated mounting points without paint, metal or trim damage. The most common mistake is overloading — always respect the vehicle's roof load rating in the handbook.
How long does delivery take?
Most roof bar kits ship within 1–3 working days to UK mainland addresses, and delivery is free on orders over £40. We dispatch from our Northampton warehouse Monday to Friday.
Can I return roof bars if they don't fit?
Yes — we offer 60-day returns on all roof bar kits, including opened boxes where you've tried the fit. Backed by our Guaranteed Fit promise: if our reg lookup picked the wrong kit, we'll refund your return postage too.