What is the difference between an indoor and an outdoor car cover?

Indoor covers: dust and knocks

In a garage the threats are dust, a bike handlebar brushed against a wing, and the cat. MGOC Spares describes its indoor cover as a breathable lightweight material that keeps dust off the panels without abrasion or moisture-trapping, with a soft-lined construction. Dust matters more than it sounds: the same retailer notes that dust settling on paintwork over winter forms a fine abrasive layer that scratches the paint when it is removed.

Outdoor covers: rain, wind and sun

Outside, a cover has to keep rain off and stay in place. Halfords recommends fabric that is waterproof yet breathable, so rain stays out while condensation can evaporate, and a cover that fits snugly so it will not flap in the wind. MGOC Spares makes the same point about fit: a generic cover that is too large billows in the wind and abrades the paint at the contact points.

Side by side

Both must breathe

Whichever type you buy, avoid anything that seals the car in. MGOC Spares warns that a fully impermeable cover traps any moisture beneath it and holds it against the paintwork. "Waterproof" on an outdoor cover is only good news if the listing also says it is breathable.

Sizing

Universal covers come in sizes such as small, medium and large, or by length range, and the car's overall length is the number that decides it. Ourcar cover length guide shows how to measure, and thecar cover buying guide covers fabrics and fixings.

Common mistakes

• Using a garage dust cover on a driveway because it was cheaper.
• Buying a waterproof outdoor cover with no mention of breathability.
• Choosing a size by car category instead of measured length.
• Covering a dusty or dirty car, indoors or out.

Related reading

• Should you cover your car in winter?
• How to measure your car for a cover
• Car cover buying guide
• Our car cover picks

Frequently asked questions

Can I use an indoor car cover outside?

No. MGOC Spares, which sells both types for classic MGs, says indoor covers should not be used outside because they offer no meaningful weatherproof protection. If the car lives outside, buy an outdoor cover.

Can I use an outdoor cover in a garage?

It will work, as long as it is breathable. It is usually heavier and bulkier than an indoor dust cover, so it is more awkward to put on and take off, but it will not harm the car in a dry garage.

Do I need a cover at all in a garage?

Not always. The main job of an indoor cover is to keep dust off. MGOC Spares notes that dust settling on paintwork over winter creates a fine abrasive layer that can scratch the paint when it is wiped or the cover is pulled off. If the car is used often and the garage is clean, you may not need one.

How do I pick the right size?

Measure your car's overall length, bumper to bumper, and compare it with the range the cover lists. Universal covers are sold in sizes such as small, medium and large, or by a length range. The Favoto hatchback cover, for example, is listed for cars from 157 to 171 inches long, which is roughly 399 to 434 cm.