The 85 percent towing rule explained, a UK caravan guide

Quick answer

The 85 percent rule says your fully loaded caravan (its MTPLM) should not weigh more than 85 percent of your tow car's kerbweight. It is a stability guideline promoted by the Caravan and Motorhome Club, not UK law.

Two things still set the legal limit: the car manufacturer's towing capacity for your specific vehicle, and your driving licence entitlement.

Who this guide is for

• First time tow car buyers trying to pick a sensible caravan weight.
• Experienced towers wondering when it is reasonable to go above 85 percent.
• Anyone confused by adverts that quote "85 percent match" without explaining where the number comes from.

What 85 percent actually means

The figure compares two numbers:

• Kerbweight of the tow car, as quoted by the manufacturer, normally with a full tank of fuel and a nominal driver.
• MTPLM of the caravan, the maximum it is allowed to weigh fully loaded.

If the caravan MTPLM is no more than 85 percent of the car kerbweight, the caravan is unlikely to dominate the car in a stability event. That is the entire point of the rule.

Why it is guidance, not law

The legal towing limits in the UK are set by:

• The car manufacturer's plated towing capacity for that exact vehicle.
• Your driving licence category (post-1997 B, B+E, or grandfathered entitlements).
• The combined train weight (the maximum the car plus trailer can legally weigh together).

You can be inside the 85 percent guideline and still be illegal if you exceed any of those. You can also be above 85 percent and still legal. The rule is about confidence and stability, not legality.

When 85 percent is the right ceiling

• You have never towed before.
• You drive a relatively light car with a short wheelbase.
• You tour with full water, full lockers and bikes on the back of the caravan.
• You expect to drive in exposed conditions, motorways with high sided lorries, ferry routes, mountain passes.

When experienced drivers go above 85 percent

Experienced caravanners regularly tow between 85 and 100 percent of kerbweight, especially with heavy estate cars, large SUVs and pickups. That is a legitimate choice when:

• The car has a high plated towing capacity well above the loaded caravan weight.
• The noseweight is set correctly (typically 5 to 7 percent of the loaded caravan weight, within the limit set by the tow ball and car).
• Load is packed low and over the axle, not at the back.
• Tyres on both the car and the caravan are within age and load rating limits.

This guide does not certify that any given outfit is safe. It explains the rule, the buyer still owns the matching decision.

Buyer checks before you commit

1. Get the tow car's kerbweight from the V5C or manufacturer data, not the brochure.
2. Get the caravan's MTPLM from the manufacturer plate, not the advert.
3. Use our caravan towing calculator or towing capacity by registration to confirm the legal limits for your car.
4. Confirm licence entitlement for the combined weight.
5. Plan a weighbridge visit once loaded.

What this guide is not

This is buyer guidance only. It is not a safety certification, insurance advice or a legal opinion. If anything in your outfit is borderline, get a recognised specialist or your insurer to review it.

Related tools and guides

• Caravan towing calculator.
• Check towing capacity by registration.
• Caravan weights explained.
• What is MTPLM.
• Browse used caravans.