Units Conversion: Understanding the Differences

Okay, I just looked up the repair manual from VW, and the first thing I encountered was a misunderstanding.
"the units of measurement listed there and those in my measurement report from the tire dealer."

Basically, I don't understand how the different pieces of information relate to each other.
The vehicle data provided to the tire dealer should be (almost) identical to the data from the vehicle itself, allowing for accurate calculation or comparison.
VW thread replacer. I know it's a VW thread replacer, but I don't know how to convert it or put it into a direct comparison.
Can someone explain the relationship between the units of measurement used by a tire dealer and those used in a VW repair manual?

According to the VW repair manual and the tire dealer, my suspension is designated as 2UC – which I have verified and is correct.

Let's take three examples from it:

1. Example:

At the tire dealer, the vehicle data specifies the following for the front axle: Caster angle: Minimum -1°11', Maximum -0°11'.

According to the VW repair manual, the specified camber (when aligned straight) is -41' +/- 30'. The maximum allowable difference is 30'.

2. Example:

At the tire dealer, the vehicle data specifies the following for the front axle alignment: Minimum 0°00', Maximum 0°10'.

"On the VW repair manual, the specified track difference angle at 20 degrees of steering angle to the left and right is: 1°40' +/- 20'."

3. Example:

At the tire dealer, the vehicle data specification for the front axle is as follows: Caster angle: Minimum 7°17', Maximum 8°18'.

According to the VW repair manual, the toe angle is: 7°47' +/- 30'. The maximum allowable difference between both sides is 30'.

Survey report

Part 1 and 3 are quite clear:
1 degree is equal to 60 minutes, so the given information is correct.

Part 2 seems to be based on a different measurement method.

best regards
Findus.

Hi.
Number 2 is not comparable.
These are completely different measurements.
Once the track is aligned straight ahead, then there is a track deviation when the steering angle is applied.

Best regards from Berlin.
olli

ok - understood - thank you very much.

I'm not okay with the difference in height of 46mm between the right and left sides. I'll probably have to take it to another VW dealer and "point out" the issue so they can do a better job - and then have it checked again at another reputable alignment shop.
It's difficult to completely verify what they are doing, as paper, as we know, is patient.

I'm also not happy with the alignment. I suspect that the first VW dealer (who, in many other cases, consistently did shoddy work) shifted the aggregate carrier towards the front of the car. Maybe the eager apprentice loosened too many screws at once...

I'm not sure what could be done in that situation, or how to recover the lost momentum.

Hi,

If you find the right specialist, they can adjust everything perfectly symmetrically. They can even compensate for a potentially misaligned rear axle using the front axle.
But if the car is properly positioned on the road and driving straight, then I would consider it.

Best regards from Berlin.
olli

Catching the right specialist will definitely cost a lot of money.

"I'm very confident in my tires; I've been using this type of tire for over 18 years, and I've consistently achieved the same mileage per year. I'm definitely a creature of habit."

If everything is set up correctly, and my tires wear down properly, then the plan is to have about 4.5 to 5mm of tread left after the second winter, allowing me to use the same tires for two winters. After the second winter, I can then run the tires down significantly during the summer months before putting on new ones before the third winter. Ideally, this is a perfect system. And that's exactly how it always worked with the last six company cars (new cars).

If the tires are wearing down like they are now, I don't want to use them for a second winter. It's a shame to have to replace the tires after only 40,000 km, especially since I know from experience that I could easily get over 60,000 km out of them.

Quote:

I'm not happy with the difference of 46' in the slope between the right and left sides. I'll probably have another VW dealer take a look and "point it out" to them so they can do a better job - and then I'll have it checked again at another reputable surveying station. It's difficult to completely verify what they are doing, as paper, as we know, is patient. I'm also not happy with the after-sales service. I suspect that the first VW dealer (who, in many cases, consistently did shoddy work) shifted the aggregate carrier in the direction of travel. Perhaps the eager apprentice loosened too many screws at once... I don't know what could be done in that situation, nor do I know how to restore the lag in that case.

Where did you read that?

Front stall after: Li 54 minutes, Re 1 degree. Difference 6 minutes --> which is nothing, so OK.

Toe-out is acceptable and, in this case, does not lead to increased tire wear.

The difference in track gauge on the right is noticeable.

See here: http://de.wikipedia.org/wiki/Lenkung
Are you watching "Ackermann"?

There might be a problem with this, but it doesn't really fit with the plausible overall angle (the included angle, which is the sum of the rake and spread on each side).

Rear axle alignment, 6 minutes per side, also OK.

I find the measurements to be perfectly fine, except for the track gauge difference angle.
With the current pre-set value of 2 minutes, the vehicle should generally feel a bit more agile in its response compared to the previous setting of -15 minutes.

Where exactly is the tire problem ?

Have you ever considered that tire manufacturers are also constantly developing and improving their products?

Here's the translation:

"One more thing: Is the steering wheel perfectly straight when driving straight, or was it adjusted after the alignment?"

A steering wheel that is not perfectly vertical is almost always an indication that something went wrong during the alignment process, or that the values on the report do not match the actual vehicle.
If it's standing upright without being tilted, you can be 99% sure that the paper and the vehicle are the same.

Hello Uncle BM,
Okay, maybe it's my age - I'm almost 50 - but something just isn't quite right with me anymore. You're of course right - it's only 6 minutes .

Also, besides that, I'm not a suspension expert - I come more from the two-wheeled vehicle area - so things are a bit simpler with the suspension there .

Regarding the issue with the track gauge difference, I'll do some research - thank you.

While I've stuck with the same tire type for over 18 years, the manufacturer has obviously revised the product multiple times and occasionally added a new feature to the name. However, fundamentally, it's still the Vector xyz.

Here's the translation:

Where the problem was and why I visited the surveying equipment company after 40,000 km: http://www.hkss.kohl.com/Reifenprofil40Td.jpg

It should be noted that the installation of these complete wheel sets was preceded by a measurement at a VW dealership. This was done as a precaution, as I had also just purchased the car with 15,500 km on the odometer.
Unfortunately, I didn't receive a detailed document regarding the survey.

Quote:

Here's where the problem was and why I visited the surveying company after 40,000 km: http://www.hkss.kohl.com/Reifenprofil40Td.jpg

You're not serious, are you?

It's surprising that the Vector didn't fail earlier due to erosion or similar profile damage. It's also possible that the Vector isn't the optimal fit for the vehicle.

I wouldn't worry about it too much, and I wouldn't waste money on pointless measurements.

Instead, you should invest in a good set of summer and winter tires.

There is no tire that performs equally well in both summer and winter conditions.
It only takes slightly above-average road temperatures and a few hundred kilometers driven at high speed, and essentially, that was the end for your tires.
You've probably heard of those things too, especially when it comes to two-wheeled vehicles.

Am I mistaken, or does it seem that the trend towards very soft rubber compounds for summer tires is becoming more pronounced? Many people in my circle of acquaintances report that new summer tires have a lifespan of only 20-30,000 km until they are completely worn out (tread depth = legal minimum). For some, this is half of their annual mileage, which means a new set of summer tires every year. What is noticeable is the uniform wear patterns and a nearly uniform wear on the front and rear axles. Therefore, one cannot conclude either a problem with the suspension or a tire-wear-promoting driving style. Newly purchased replacement tires also always felt very soft during the fingernail test . The Conti EcoContact 3 (standard equipment, for example, on the Renault Clio) and various supposedly fuel-efficient Michelin tires have proven to be particularly prone to wear.

I don't want to talk too much more about the tires, but – as I said – the Vector outperforms almost every summer and winter tire. In heavy rain with the Passat 180, and in winter, it goes past the snow and those supposedly great winter tires, right up to the parking spaces directly at the ski lift. After over 18 years, you gain some undeniable experiences, and I've even managed to get over 70,000 km with a single set (on a 90hp Passat), and around 64,000 or 66,000 km with the 140hp Passats. No one can criticize THAT tire.

No offense, but thank you for your presumed opinion about the tire. I can only share my experience.

BM wrote:

Quote: Here's where the problem was, and why I visited the surveying company, after 40,000 km: http://www.hkss.kohl.com/Reifenprofil40Td.jpg You're not serious, are you? It's surprising that the Vector didn't fail earlier due to erosion or similar profile damage. It's also possible that the Vector isn't the optimal fit for the vehicle. I wouldn't worry about it too much, and I wouldn't waste money on pointless measurements. Instead, you should invest in a good set of summer and winter tires. There is no tire that performs equally well in both summer and winter conditions. It only takes slightly above-average road temperatures and a few hundred kilometers driven at high speed, and essentially, that was the end for your tires. You probably know about it too, from bicycles or other two-wheeled vehicles.

Hehe.

Okay, I see that you're mostly driving alone in the car, and maybe you're not quite as slim as you used to be?
And you drive slower through right-hand curves than left-hand curves - assuming all settings are correct.

Best regards, Rainer.

@Uncle BM: I could be incredibly frustrated right now, having let myself be persuaded to write about my experiences with that particular tire brand/type.
I didn't actually want to impose this on anyone - I'm sorry!
I hope that didn't come across negatively to you.

Well, Rainer, so far I've only used Passat tires – I've had 6 new sets on new cars. And I've never had any complaints about them; all of them wore down perfectly. At least, I can't recall a single instance where the tire dealer or the person changing the tires (every 2 years) wasn't extremely surprised. I was always able to influence and perfect the even wear of the entire tread by adjusting the tire pressure.

Maybe Uncle BM is right when he says that the tires need to "fit" the car – I'm driving a Golf for the first time, and these are the first tires I'm putting on a Golf V Variant. But it will take many years before I come to accept that, if it's true.

Yes, that's right - I weigh 90kg, but you can't go any slower through the left-hand turns than I already am going through the right-hand turns - and I never turn the steering wheel unless the tires are rolling - never.

Okay, enough with the jokes - seriously! It didn't match the previous settings, which is why my tires look like this after 40,000 km.
I ordered 2 new ones - the delivery time is 10 weeks - then we'll see how they perform.

With the information I have now, I'm doing okay - I can handle it.

Thank you again to Uncle BM - the explanation and the crucial hint about where further improvements could be made came from you - thank you.

My contribution was meant as a joke.