Caravan and trailer tyres are dangerous in a different way to car tyres: they usually fail from age, not mileage. They sit unused for months, the rubber perishes from the inside, and the standing weight creates flat spots, so a tyre with full tread can still be unsafe to tow on. A pre-tow check every season is essential.
If you only check one thing, check the age. After that, it's pressures, condition and the spare. Here's the full picture before you hitch up, including how to read the date code and what to do if a tyre fails while you're towing. Our tyre date code checker turns the four digits into a week, a year and an age.
Why towing tyres are different
Unlike a car tyre that wears out through use, a towing tyre typically ages out while parked. Months of standing, sunlight and damp do the damage long before the tread does, and the loads involved are unforgiving.
- Age over use. Many caravan tyres age out long before the tread wears, so check the DOT date stamped on the sidewall.
- Flat-spotting from standing in one position for months on end, which can cause vibration when you set off.
- UV and weather damage from being parked outside uncovered, leading to cracking in the rubber.
- Heavy, sustained loads on long motorway tows that build heat, especially on a fully loaded van.
Your pre-tow checklist
Run through this before every trip, and do a fuller inspection at the start of each towing season:
- Check the age. The Caravan and Motorhome Club advises replacing caravan tyres at five years and never running them beyond seven, regardless of tread.
- Inspect for cracking, bulges and flat spots all the way round, including the inner sidewall you can't see at a glance.
- Set the correct pressure, often much higher than a car; check the handbook or weight plate.
- Mind the load and speed rating, towing tyres have specific limits you must not exceed.
- Don't forget the spare, it's usually the oldest and most neglected of the lot.
- Check the wheel nuts are tight to the correct torque, especially if the wheel has been off.
Caravan wheel nuts often need a different torque from the car's, and the figure is in the caravan handbook, not the car's. Recheck them after the first few miles of the season.
Reading the age code
The age of a tyre is stamped into the sidewall as part of the DOT code, and it's the single most important check on a caravan or trailer. Look for the last four digits: the first two are the week of manufacture and the last two are the year. So "2519" means the 25th week of 2019, making that tyre well over five years old.
Because a perished tyre can look perfectly fine, the date is what catches the dangerous ones. If you've bought a used caravan, assume the tyres could be much older than the van's apparent condition suggests, and check every wheel including the spare.
On the road
A caravan or trailer tyre failure can trigger dangerous snaking, where the unit sways from side to side and can pull the towing car with it. If it happens, don't brake hard or steer sharply. Ease off the accelerator gently and keep the wheel straight to let the outfit settle, the same principle as a car blowout, then pull over somewhere safe.
Correct pressures and a sensible towing speed are your best defence, because snaking often starts with an under-inflated or overloaded tyre. Spreading the load correctly and not exceeding the noseweight also helps keep the outfit stable.
Pressures, load and the weight plate
The right pressure for a caravan or trailer tyre comes from its weight plate and handbook, and it is usually well above a car tyre's. Guessing from the car's figures is a common mistake and a leading cause of failures.
Start with the weight plate, normally near the door or on the A-frame. It shows the maximum technically permissible laden mass (MTPLM), the most the unit may weigh fully loaded. The handbook gives the tyre pressure for that weight. If you tow well below the maximum, some manufacturers publish a lower figure; if not, use the full-load pressure.
Then check the tyres can carry it. The load index on the sidewall converts to kilograms per tyre, and two tyres on a single axle must together exceed the axle's rated load with a margin. Our guide to load and speed ratings has the conversion.
A tyre with a lower index than the caravan needs is unsafe even at the right pressure.
Noseweight matters too. The downward load on the towball, commonly set at around 5 to 7% of the caravan's laden weight and never above the car's or hitch's limit, keeps the outfit stable and also loads the car's rear tyres. Heavy items belong low and over the axle, not in the rear locker.
Set pressures cold, before you tow, and check the car's rear tyres against its loaded figure at the same time. Twin-axle caravans need all four checked, including the pair you cannot see easily from the kerb.
UK towing speed limits
When towing a caravan or trailer, the national speed limits drop to 60mph on motorways and dual carriageways and 50mph on single carriageways. Lower posted limits still apply as normal. The limits are set out on GOV.UK.
These limits are also close to what the tyres want. Caravan tyres run hot on long motorway tows because they carry a high, constant load with little airflow behind a large body, and heat is what breaks down an ageing tyre. Sitting at 60mph rather than creeping above it keeps that heat in check.
The tyre's own speed rating still applies. Many caravan and trailer tyres carry a modest rating, and a few older trailer tyres are marked for lower speeds still, so check the letter on the sidewall against the table in our load and speed guide. Where the tyre's rating is lower than the road limit, the tyre wins.
Two more rules of the road worth knowing. On a motorway with three or more lanes, a car towing a trailer must not use the right-hand lane.
And if the outfit starts to snake, the fix is to ease off gently rather than brake, as described in the section above; going slower in the first place is what stops it starting.
Storing the caravan between trips
Tyres age fastest while the caravan is parked, so the way it is stored decides how many seasons they last.
- Keep the weight off, or move it. A caravan left on its tyres in one spot for a whole winter flat-spots them. Either roll it a quarter turn every few weeks, or take the weight on axle stands or wheel-saver supports so the tyres are not bearing the load. See flat spots on tyres.
- Inflate to the full-load pressure for storage. A tyre losing pressure over months of standing sits on a smaller, more deformed patch. Check it monthly and reset before towing.
- Keep the sun off. UV hardens and cracks the sidewall. Wheel covers or parking with the tyres in shade slow it noticeably.
- Keep the tyres off bare earth and out of standing water. Park on paving, boards or gravel.
- Clean the tyres with plain soap and water before storage.
- Check the spare and its pressure at the same time. It is usually the oldest tyre on the unit.
Whatever you do over winter, do a full walk-round in spring: cracking between the tread blocks and in the sidewall, bulges, and the DOT date on every tyre including the spare. A tyre that shows fine cracks when you flex it is finished, however deep the tread.
Extra protection: TPMS and safety bands
Two add-ons give a caravan or trailer tyre a second line of defence: a pressure monitor to catch a leak early, and a safety band to keep a failed tyre on the rim.
Aftermarket TPMS. Most caravans have no pressure monitoring, so a slow leak on the offside tyre can go unnoticed for the whole tow. Aftermarket kits use sensors that screw onto the valves and report to a display in the car.
They are not a substitute for a gauge, but they turn a silent leak into a warning you can act on before the tyre overheats. If you fit one, use the manufacturer's caps and check the sensors have not loosened after a few trips.
Safety bands. A band fitted inside the tyre around the well of the wheel stops a deflated tyre coming off the rim, so you keep steering control and can stop rather than snake.
They are fitted when the tyre is off the wheel, which makes a tyre change the natural moment to add them, and they need a fitter who has done it before.
Neither replaces the basics: correct pressure, a tyre within its age limit, the right load index, and a proper spare. But on a long tow with a family behind you, both are cheap compared with the alternative. The motorhome tyre safety guide applies the same thinking to a motorhome.
Getting a caravan or trailer tyre replaced
There's no need to drag a caravan or trailer to a garage on a doubtful tyre. We can fit tyres at your home, or at a storage site with the site's permission, from our base at Brent Cross, NW2, where the size can be sourced; call with the size from the sidewall and we will tell you whether we can do the job, and check age, pressures and condition while we are there.
