Let’s start with what most people think.
A wheel spacer is just a piece of metal that pushes the wheel out.
So as long as the bolt pattern matches, it should work… right?
That’s the assumption.
That’s also where the problems start.
Because there are two very different types of spacers, and most people don’t realise which one they’re buying.
What People Think the Difference Is
If you search this topic, you’ll usually get a simple explanation:
- Hubcentric = better
- Lugcentric = cheaper
That’s about as far as it goes.
But that doesn’t explain why one works properly and the other can cause issues.
So let’s break it down properly.
What Hubcentric and Lugcentric Actually Mean
Hubcentric Spacers
A hubcentric spacer locates on the hub using the centre bore.
It then provides a new centre lip for the wheel to locate onto.
So the load path looks like this:
Hub ? Spacer ? Wheel
Everything stays centred through the hub.
That’s how the car was designed from factory.
Lugcentric Spacers
A lugcentric spacer does not locate on the hub tightly.
Instead, it relies on the bolts to centre the wheel.
So the load path becomes:
Bolts ? Wheel ? Spacer (floating)
That’s a completely different setup.
And it’s where the problems begin.
Why Lugcentric Spacers Cause Issues
The problem is small movement.
Even if the spacer looks like it fits, there is usually a tiny amount of clearance.
At low speed, you won’t notice it.
At higher speed, that small misalignment becomes vibration.
You’ll feel it through:
- The steering wheel
- The seat
- The whole car at certain speeds
It can also lead to uneven load on the bolts.
Over time, that’s not what you want.
Why Some People Say “Mine Are Fine”
This is where it gets confusing.
You’ll always find someone who says:
“I’ve run cheap spacers for years and had no issues.”
That can be true.
A few reasons why:
- Their tolerances happened to be tight enough
- The car isn’t driven hard
- The wheels self-centred during install
So yes, sometimes you get away with it.
But it’s not consistent.
That’s the key point.
How Proper Engineering Fixes the Problem
The fix is simple in theory.
Make the spacer behave like part of the hub.
That means:
- Tight centre bore tolerance
- Proper hub lip
- Flat mounting faces
- Correct material
When all of that is right, the wheel sits exactly where it should.
No reliance on bolts to centre anything.
No movement.
No vibration.
If you look at properly machined hubcentric wheel spacers, this is exactly what they are designed to do:
Why Tolerances Matter More Than You Think
You’re dealing with rotating mass.
Even a small error becomes noticeable once the wheel is spinning.
For example:
- 0.1mm off-centre at the hub
- Multiplied at the tyre edge
- Felt through the car at speed
That’s why cheap spacers often feel fine at 30 mph, but not at 70 mph.
Precision matters here.
Real-World Example: Porsche Fitment
Cars like Porsche make this very obvious.
The factory tolerances are tight.
The steering feel is sharp.
So any small issue shows up quickly.
If you install a spacer that doesn’t locate properly:
- You’ll feel vibration straight away
- The car won’t feel right
But if the spacer is hubcentric and machined correctly:
- The driving feel stays the same
- Just with improved stance
For Porsche wheel spacers, using the correct spacer type makes a noticeable difference:
When Lugcentric Spacers Might Be Acceptable
There are limited cases where lugcentric spacers can work.
For example:
- Very thin spacers (3–5mm)
- Temporary setups
- Low-performance applications
Even then, you are relying on the bolts to centre the wheel.
So it’s still not ideal.
A Simple Rule to Follow
If you want to avoid problems, keep it simple:
- Spacer must locate on the hub
- Wheel must locate on the spacer
- Bolts should only clamp, not centre
If all three are true, the setup will work as intended.
Final Thoughts
The difference between hubcentric and lugcentric spacers is not just terminology.
It’s the difference between a properly supported wheel and one that relies on the bolts to hold everything in place.
Some setups will work either way.
But if you want consistent results, smooth driving, and no vibration, the choice is clear.
Get the fitment right at the hub, and everything else falls into place.
