Tire Wear Inside: Causes for Long Vehicles

This topic was briefly mentioned in another thread, but I want to address it separately here because some people seem to be experiencing issues with their tires collapsing inwards.

Inner edge wear is typically a tracking issue. Negative camber is only secondarily responsible. Specifically, it's toe that causes the tires to wear on the inside.

When turning, the front axle exhibits toe-out. This is due to the difference in toe angle (which is standardized at 20 degrees for the outer wheel). This is because the inner wheel travels a smaller radius than the outer wheel during the turn.

The longer the car, the smaller the required track difference angle needs to be. The track difference angle is determined by the suspension strut (wheel bearing housing). If VW uses components from smaller vehicles, this would theoretically lead to wear on the inner edges of the tires.

Solution: Set the axle to the correct alignment.
If you compare the alignment settings of a Golf 2 and a Corrado VR6, or an A4 quattro and an RS4, you'll notice that the high-performance sports cars often have positive camber. Positive camber means the axis is under tension, which makes the handling feel tighter. Furthermore, the car feels more aggressive/nervous/direct because the outer wheel already has some steering angle. However, it doesn't necessarily feel bad...

In addition, a negative camber is used, which also puts stress on the axle (causing the wheels to turn inwards) and further increases the load on the outer wheel. However, since you're going downhill on the inside, I would be cautious about that.

So, if you're experiencing issues with tires wearing unevenly on the inside, compare your alignment settings to those of higher-powered vehicles and find a compromise. For example, you could adopt the toe setting and adjust the negative camber towards 0 degrees, moving it closer to the tolerance limit, to prevent further inner tire wear.

Hello Martin,

danke für die super Erklärung. Da ich hauptsächlich meine km auf der Autobahn mache, also wenig Kurven, werde ich meine Räder jetzt mal einfach auf etwas Vorspur stellen (Sollwert Passat ist O°). Kannst Du nochmal kurz begründen warum der negative Sturz keinen großen Einfluss hat? Mein Passat hat schon das Plus Fahrwerk vom VR6. Da sind die negativen Sollwerte vom Sturz kleiner als beim Normalfahrwerk. Spboth are at 0°.

Best regards, Albrecht.

The camber isn't as critical because it doesn't hinder the free rotation of the axle as much as incorrect toe. If the axle rotates freely, it won't rub and won't excessively wear. Toe is a factor in wear, and with its adjustment, you can correct for uneven wear.

What does a negative target ride height mean, resulting in less drop than with a standard suspension? Does it really bring the car closer to zero ground clearance? So, you actually drive more like Michael Schumacher with the base suspension compared to the 'Plus' axle system.
Finde ich seltsam dass das VW beim Passat das so gemacht haben soll. Ich bin eher bei Golfs unterwegs und da ist das nicht so. Die größte Steigerung des Negativsturzes in der Golfklasse ist der Corrado. BThe same applies to the A4.
That's at least what the computer at ATU spat out when I had my beloved, now-crashed, Golf measured there. It makes sense, though.

@ Albrecht:
What do you mean by 'Plus suspension'? Was that already standard, or did you have it installed later? I'm interested because I also drive one of these cars, but I don't know much about the car's suspension yet.

@ampac

The "Plus" suspension can be identified by the 5-hole wheel hubs. It was standard on the Passat 35i with VR6, 2.0 16V, and 81 kW TDI engines. On the Golf 3 TDI, it was likely optional or only available on the GT model...?

@Martin

It doesn't make sense to consider the difference in descent rate when calculating the pitch-up angle during a forward flight maneuver, which is correct. However, I had it in mind differently. I should review this again sometime, taking into account my new knowledge, especially regarding the track deviation angle.

Best regards,
Albrecht.

Hello everyone,

So, I went for another wheel alignment today.
Result: Wheel alignment is OK; the toe was slightly positive but within tolerance. When I asked the dealer about the cause of the tires wearing out on the inside, he said it's not unusual for tires, especially those on the front axle with heavy diesel engines, to reach their load capacity limit. In my case, this seems to be happening with a load rating of 83 (which is the lowest possible). He suggested using branded tires (Michelin, Continental, etc.), as this is less likely to occur. Alternatively, reinforced tires would also help. I had TOYO Proxes T1S tires. I'll take another picture when I install the winter tires tomorrow.

Best regards,
Albrecht.

Well, my BMW 5-series isn't exactly lightweight, but the tires generally wear out on the edges.

Hello Christian,

You always need to consider the axle load in relation to the tire's load capacity. Your C4 likely has tires of size 195/65 R 16 or larger, which have much higher load capacities. The C4 also had V6 engines and a 4.2-liter V8 quattro variant. Those probably weigh even more than the 5-cylinder diesel. Of course, the standard axle geometry also plays a role.
I took another picture. This is definitely not normal wear and tear. Everyone can form their own opinion about it.

Best regards,
Albrecht

That's really not normal wear and tear.


Positioning the fender edge onto the tire shoulder...

Quote:

Positioning the fender edge on the tire shoulder...

Please read the inside first!

@Albrecht:

Hi,

I find this very extreme because the severe wear is almost exclusively limited to the outermost edge. The wear indicators on the surface all appear to be at a similar distance from the tread depth.

Can you rule out the possibility that the front suspension is so worn that excessive toe-in occurs during braking due to play in the components?

Quote:

I find this very extreme because the severe wear is almost exclusively limited to the outermost edge. The wear indicators on the surface appear to still have a similar distance to the tread depth.

That's exactly right.

Quote:

Can you rule out the possibility that the front suspension is so worn that, for example, excessive toe-in occurs during braking due to play in the components?

Yes, I can rule that out.

If it turns out to be something else, I'll be able to report on it in the spring. By then, the winter tires will certainly be ready. However, they have a higher load capacity and were already used last winter without any problems.

Best regards,
Albrecht.