The 85% Rule: Helpful Guide or Misleading Myth?
Few things in caravanning spark as much debate as the 85% rule.
Some people swear by it.
Others dismiss it entirely.
And many newcomers are left wondering whether they’re breaking some unwritten law.
So what is the 85% rule really — a helpful guide, or a misleading myth?
The honest answer is: it can be either, depending on how you understand it.
Let’s clear it up calmly.
What Is the 85% Rule?
The 85% rule suggests that:
A caravan’s fully loaded weight should not exceed 85% of the tow car’s kerbweight.
That’s it.
No legislation.
No enforcement.
No fines attached.
It’s not a legal requirement — it’s a guideline that’s been passed around caravanning circles for years.
Where Did It Come From?
The 85% rule didn’t come from lawmakers or manufacturers.
It emerged as a rule of thumb, designed to:
Encourage margin
Discourage mismatched outfits
Help newcomers avoid stressful first experiences
In short:
It was created to build confidence, not compliance.
Why Some People Find It Helpful
For newer caravanners, the 85% rule can:
Act as a confidence buffer
Reduce anxiety on early trips
Encourage lighter loading
Promote forgiving handling
If you’re new to towing, staying well within limits often:
Feels calmer
Feels more predictable
Makes learning easier
Used this way, the 85% rule can be a useful training wheel, not a rigid rule.
Why Others Say It’s a Myth
The criticism usually comes from experienced caravanners — and they’re not wrong either.
The 85% rule:
Isn’t legally recognised
Doesn’t account for modern vehicle design
Ignores suspension, torque, wheelbase and braking
Can oversimplify complex setups
Two outfits at the same percentage can feel very different on the road.
That’s why many people eventually outgrow it.
The Big Misunderstanding
The problem isn’t the 85% guideline itself.
The problem is when it’s treated as:
A legal limit
A universal truth
A pass/fail test
When people say:
“You must stick to 85%”
That’s when it becomes misleading.
Legal Reality vs Practical Reality
Here’s the important distinction:
Legal limits are defined by law and manufacturer ratings
The 85% rule is neither
You can be:
Above 85%
Completely legal
Correctly insured
At the same time, you can be:
Below 85%
Legal
And still poorly loaded or uncomfortable
Percentages don’t replace good loading or good judgement.
Experience Changes the Equation
What feels sensible evolves with:
Experience
Familiarity with your vehicle
Journey length
Conditions
A newcomer might find 80–85% reassuring.
A seasoned caravanner might tow happily above that — still legally, still sensibly.
Neither approach is automatically right or wrong.
When the 85% Rule Helps Most
It tends to be useful when:
You’re new to towing
You want reassurance
You’re comparing potential outfits
You’re trying to build confidence gradually
It’s less useful when:
Treated as law
Used to judge others
Applied without understanding loading, balance and noseweight
A Better Way to Think About It
Instead of asking:
“Am I under 85%?”
A more helpful question is:
“Do I have enough margin for this setup, this journey, and my experience?”
That shift alone removes a lot of stress.
The Calm Truth
The 85% rule isn’t dangerous — misunderstanding it is.
Used sensibly, it:
Encourages margin
Builds confidence
Reduces early anxiety
Used rigidly, it:
Creates unnecessary fear
Sparks arguments
Distracts from what really matters
Where to Go Next
If this page helped, these complete the picture:
Together, they replace rules-of-thumb with understanding.
Final Thought
You don’t need to chase a percentage to tow safely.
You need:
Legal compliance
Sensible margins
A setup that feels calm and predictable
The 85% rule can be a starting point — but it should never be the destination.
