Polestar 4 Pulling Right — We Saw Three

Contents

1. Symptom — lane drift hands-off
2. Right pull, three types
3. Right pull is common
4. A familiar reading — caster offset
5. The whole process on video
6. Diagnosis order
7. What was different — the rear
8. Before and after
9. The front alone can't fix it
10. A car with no adjustment bolts
11. The tires too — 25N to 5N
12. Tires can't be undone
13. Owner's review
14. Key takeaways
15. FAQ

The Polestar 4 has been delivered in Korea since November 2024. A lot of owners came to us saying it pulls to the right. In a short window we saw three of them.

All three pulled right. Some arrived with an alignment already called normal. But once we dug in, the cause was a little different each time. This is what we measured and judged on the third car.

Symptom — lane drift hands-off

Most owners had already had it adjusted a few times. It is a new car, so the warranty is still valid, and they were likely serviced under warranty first. When that did not solve it, they came to us.

The first thing we do is a test drive. Two street lights are roughly 100m apart. Hands off over that span, within 1m left or right is normal. We repeat it, not once — ten out of ten pulls is a confirmation. This car was past that line.

Right pull, three types

First we separate the symptom. Owners describe right pull in three ways: drifting right when going straight, the wheel turning right on acceleration or braking, and driver assist hugging the right lane line.

They look alike but point to different places. This car had both straight-line pull and wheel turn together, so alignment alone was never going to answer it.

Right pull is common

Pulling right is a typical symptom. Roads are built with a slight tilt to the right so water drains off. That is called camber. So even a small alignment error lets the car drift right.

Most right pulls are solved by allowing for that camber and setting the alignment. That is the basic method. But this owner had it adjusted several times under warranty and still came to us. That means the basic method did not catch it, so we look at what comes next.

A familiar reading — caster offset

The reading looked familiar. Caster is the tilt of the steering axis. When the two sides differ, the car flows toward the side with less caster.

One car was 0.7 degrees less on the right. A Polestar 4 we had seen months earlier was 0.8 to 0.9 degrees less on the right. Ordinary cars pull hard at just 0.5 degrees, and you feel it at 0.3. With less caster, the passenger-side wheelbase came out 10mm shorter too.

Two cars in a row, same direction, similar size. That is not common. Still, we don't conclude from two or three. If the next car and the one after look the same, it becomes a question of the suspension assembly stage, not the individual car. We will write it up again once more data stacks up.

The whole process on video

Intake, test drive, measurement, adjustment, and the re-drive — the whole process is in the video.

Diagnosis order

A pull rarely has a single cause. So we erase them one by one, in order.

1. Reproduce the symptom on a test drive. Which way, and how much.
2. Separate the road camber. Roads tilt for drainage, so we strip out the pull that tilt creates first.
3. Check for torque steer under hard acceleration.
4. Measure the four-wheel angles with Hunter HawkEye 3D.
5. Measure the force the tires push with, using Road Force.
6. Adjust, then re-drive. A technician rides along to confirm.

What was different — the rear

On one car the front toe was within spec. Saying the alignment was normal was not wrong — if you only look at the front.

The problem was the rear. Rear left toe was -0.4mm, out of spec, the thrust angle was -0.04°, and the axle offset was -2mm. On a rear-based car the rear is the reference. When the rear is off, the whole car leans that way.

Before and after

Polestar 4 measured before and after (this individual car)

Item	Before	After
Rear thrust angle	-0.04°	0.00°
Rear left toe	-0.4mm	1.1mm
Rear total toe	0.1	2.2
Axle offset	-2mm	0mm
Front total toe	0.4	1.2

We brought the rear thrust angle from -0.04° to 0.00°. Rear left toe went back within spec, and axle offset moved from -2mm to 0.

The front alone can't fix it

Here is the key. The front was within spec before we touched it. But once we set the rear to 0.00°, the reference line shifted, and the front numbers changed too. Front total toe was re-set from 0.4 to 1.2.

So if you only look at the front and call it normal, this car keeps pulling. You have to re-check front and rear against the rear as the base.

A car with no adjustment bolts

There was a harder case. A Polestar 4 barely a month old, only 400km. This car ships with no caster or camber adjustment. Only front toe can be set. There are no special parts like on a BMW. You can know the cause and still not bolt it out.

So we went at it with Road Force. On our Hunter Road Force (RFW WalkAway & Revolution, first in Korea, confirmed by Hunter Korea) the front tire read 13. We treat 7 as the passenger-car limit and 9.1 as the equipment's defect threshold, so it was a maxed-out reading. The rear was 4.5, healthy. Caster set the direction, and the front tire's kickback pushed it.

With no adjustment bolts, we handled the rest through the tires. We set the toe that can be set, re-assembled the wheel and tire so their offsets cancel (matching), and placed a tire whose conicity pulls left to offset the right pull. It is how you build the best result within a car that has no adjusters.

The tires too — 25N to 5N

It is not only alignment. Tires push sideways with different force too. We measured all four with Road Force and optimized their positions.

Road Force loads the tire with real driving weight (up to 567 kg (1,250 lb)) as it spins. Two values come out. One is RFV, the stiffness-variation value that shows up as vibration. The other is lateral force and conicity, the sideways value that shows up as pull. Vibration and pull are different things.

On one car this optimization dropped the expected pull from 25N to 5N. With the angles set and the tires matched, the car tracked straight again.

Tires can't be undone

One thing to note. Even at only 400km, a sport tire has already worn. It wore in the direction of the pull, so returning it to 100% of new was not possible.

Alignment can be undone, but wear cannot. A new-car pull saves the tire the sooner you catch it. If you have been stopped by "a new car couldn't do that," check it with measured data.

Owner's review

We share the review as it is. The improvement is big, but the owner says an underlying part remains. We don't claim we caught everything either. What's left, we treat as what's left.

Key takeaways

These numbers are each individual car's measurements. Even the same Polestar 4 varies unit to unit. So we don't diagnose a cause remotely. You have to see and measure the car.

But the principle holds. A pull does not end at the front wheels. The rear, caster offset, tire force, and road camber overlap. If your alignment was called normal and it still pulls, the rest may not have been checked.

The principle and diagnosis order are in the guides section, and the Korean version of this case is here.

FAQ