Winter tires for VW Polo 9N:-(

Hello,

Yesterday, my new tires (195er Uniroyal MS 55 Plus) were quite disappointing.

On a lightly trafficked, unplowed country road with a 5% incline, there was approximately 10 cm of damp snow.
While I didn't get stuck, but at 4th gear and approximately 50 km/h (31 mph) = 1250 rpm, I couldn't give it even a little bit more gas, or the tires would spin – despite the PD (Porsche Doppelkupplung) torque weakness at low RPMs.

The road surface was barely noticeable, and the slope of the road towards the ditch required me to occasionally correct with a full hand's width of steering to the left in order to drive straight.

Instinctively, I think my old Golf 3 would have handled much better with those 7-year-old(!) 175-size Fulda Gravito tires.
The "no problem" impression was confirmed to me by the buyer of my car, who was also driving around yesterday - with approximately 4mm of tread remaining!

And that's what people generally say: that technological progress is constantly improving WRs (world records). But that's nonsense; yesterday, it seemed the opposite to me.


Does anyone here have an explanation for this?
Could it be due to the 2 cm wider tires, even though the Polo is about 100 kg heavier than the Golf, and the extra weight likely puts more stress on the front axle (6-speed transmission, larger brakes, thicker drive shafts...)?

Or are winter tires now only being optimized for comfort and similar minor aspects, while their actual winter performance has already been maximized?

I have also spent a long time researching the topic of the "ideal tire." What seems interesting to me is that there is no such thing.
Based on the reports I've read, a tire size like 155/70 R13 received excellent ratings, while a different size, such as 175/70 13, only received a passing grade. It has been discussed before that not every tire works with every car. I've now decided on an all-season tire, the Goodyear Vector 5. It does have some drawbacks compared to a summer tire in dry conditions, but not compared to a winter tire. Yesterday, on the snow, I was quite satisfied with the grip. I also had satisfactory results with the Vredestein Snowtrac II.
Perhaps the road under the snow was icy where you were. All tires perform almost equally poorly on ice. From my experience, I've always found that narrower tires perform better in snow. Rally cars, which drive on snow (or even sand), also use relatively narrow tires compared to those used on cars designed for asphalt racing.

And generally, it's said that technological progress is constantly improving WRs (world records) -> Nonsense, yesterday it seemed the exact opposite to me.


Does anyone here have an explanation for this?
Could it be due to the 2 cm wider tires, even though the Polo is about 100 kg heavier than the Golf, and the extra weight likely puts more stress on the front axle (6-speed transmission, larger brakes, thicker drive shafts...)?

Or are winter tires only being optimized for comfort and similar minor aspects, while their actual winter performance } has already been maximized for quite some time?

Haha, I had the exact same experience testing it out in the snow-covered Allgäu region yesterday. Last year, our Mercedes had Conti TS770 tires, but this year I got a set of TS790 tires with the same dimensions. The old tires were only 5 years old, but with just 5mm of tread left, they offered very little grip, and that's not fun with 280 horsepower.

Where the 770 models exhibited a tendency to strong understeer, the 790 strictly followed the steering input. The 770 consistently had problems starting on a slight incline (with the ASR system working at full capacity), while the 790 started easily and the ASR system was hardly engaged.
The 790 is also generally better than a new 770, and I've definitely noticed the improvement. Since a Benz isn't really designed for winter driving and doesn't handle snow particularly well, this makes a big difference.

In my opinion, Uniroyal doesn't produce top-of-the-line winter tires, but rather tires for the budget sector, and perhaps that's the root of the problem. The question is also whether a silica compound is used in these tires, as this is often not used in cheaper tires.

Is there a triangle with a snowflake symbol on the tire sidewall? If so, it should be a genuine winter tire; the requirements for the M&S marking are very low, and some summer tires already meet them.

Are the tires already properly worn in, and has the silicone protective layer and the rubber tabs been completely worn off?

Does your engine also have ASR/EDS? If so, could the EDS system have caused the understeer?

Okay, I've checked again. According to physics, the coefficient of friction is independent of the surface area. So, whether you have narrow or wide tires initially doesn't matter for grip; it only depends on the coefficient of friction (µ). However, with snow, the larger surface area of the tire acts like a windbreak and counteracts acceleration. The contact pressure is also different with wider tires compared to narrower ones. This contact pressure seems to be relevant on snow. The smaller the force on the snow, the looser it remains, and the lower the grip. Therefore, wider tires are not as good as narrow tires on snow.
Your slightly higher weight is offset by the wider tires, because pressure force equals pressure multiplied by area.

Well, the contact patch area is always the same for common tire sizes. It's about the size of a postcard.

With narrower tires, the long side of the tire is parallel to the direction of travel, while with wider tires, it is perpendicular. The contact area is almost always the same. Wider tires generally offer slightly more lateral grip when cornering, while narrower tires provide more traction in deep snow because the tire has 'less' snow to compress.

If the ground pressure is always the same, and the contact area is the same, then a wider tire and a narrower tire should compress the snow equally, and therefore it shouldn't make a difference, right?
It is undeniable that wider tires have a different handling characteristic than narrower tires. This is because narrower tires have a larger contact patch when cornering compared to wider tires. Therefore, narrower tires with a relatively high aspect ratio (ratio of tire height to width) also tend to feel more "nervous."

I believe it depends more on the tire itself than on the width, at least if it's not excessive. 255-width winter tires are nonsense.

I was able to convince myself of the quality of Maloya winter tires based on several cars. Last year, on my mother's Golf, they had very good performance, both without snow (wet/dry) and with snow! The year after that, she didn't get Maloyas anymore but some 'brand-name' tires (Fulda, Fredestein, I don't remember exactly ).
'These things were significantly worse to drive in every aspect! That's why we (including me for my new Leon) already ordered Maloya tires for this year, even in the summer!'
The Golf has 195/xx-15 tires, and mine has 205/55-16 tires (due to the larger brakes and the need for more space between the rim and the brake caliper). I'm extremely happy with them. They're naturally a bit worse than summer tires in dry conditions, but there's hardly any difference in wet conditions. And they're great in snow, providing a good feel and plenty of grip.
'Regarding liability in snow or slush, no differences can be observed between the various tread patterns.'

Julian wrote:

In my opinion, Uniroyal doesn't produce top-of-the-line winter tires, but rather tires for the low-budget sector, and perhaps that's where the problem lies. The question is also whether a silica compound is used, as this is often not used in cheaper tires.

Well, the price range is comparable to the (subjectively) better, older Fuldas on the G 3.

My online research before purchasing the WR tires indicated that the Uniroyal tires already contained a silica compound.
The Fuldas cars from 1997 definitely didn't have...

Quote:

Is there a triangle with a snowflake depicted on the tire sidewall? If so, it should be a proper winter tire; the requirement for the M&S marking is extremely low and is sometimes already met by summer tires.

Snowflake, yes, but in a circle.

Quote:

Are the tires already properly worn in, and is the silicone protective layer and the rubber flags completely worn off?

Estimated mileage: 1000 to 1500 km since purchase. The rubber wear indicators have been gone for a long time (except for those in the tread grooves), as I brake less before corners and take them at a significantly faster speed than the average driver.

Quote:

Does your engine also have ASR/EDS?

If so, could the EDS have caused the understeer? }
I had the ESP system deactivated; I only have ABS on board.
Brake tests (with active ABS) actually gave me a better understanding of the tires than their traction and lateral grip ratings.

According to the ADAC test report, the Uniroyal Plus 5 also exhibits some weaknesses in snowy conditions and has a high rate of wear.
Braking performance on snow: 2.5 (out of a possible score, presumably).
Starting price: 2.3.
The really good ones here have scores significantly below 2.
Vector 5
Braking on snow: 1.7.
Starting price: 2.3.
And that's for an all-season tire. So why bother changing them.

wutz wrote:

According to the ADAC test report, the Uniroyal Plus 5 . . . and also exhibits high wear.

Let's see, then I might have to replace them soon (with something better) .

I'm driving on Dunlop Winter Sport tires, size 195/65 R15.

I probably lack experience with high-quality winter tires because I used to drive an old Passat with generic tires – always with that typical loud humming noise starting at 80 km/h.

However: It's extremely quiet, performs very well in snow, and in my personal opinion, it doesn't have any weaknesses in other areas either – and all that at an acceptable price.

For those who are interested: I recommend him - the ADAC also does .

Happy New Year!
herwig

Hi,

If we only consider the contact area between the tire and the road surface, then, as a general rule: the wider the tire, the better.
Reason:

Frictional force = coefficient * area * force.

The product of 'area * force' is constant for a car, but the coefficient increases with the contact area.

So far, so good on solid surfaces (ice, packed snow, dry/wet asphalt). However: A wide tire has a huge problem in slush and wet conditions: The water has to be moved much further, and more water needs to be transported for the tire to make contact. In addition, there's the previously mentioned issue: surface pressure. The tire is supposed to compress loose snow, and the individual tread blocks then grip into this relatively firm surface.
Therefore, the goal is to find a compromise between high friction and easy displacement of water/slush.
Don't forget that 225-size tires tend to splash a lot of water onto the sides of the car in the winter.


Regards,
Sure, here is the translation of the text from German to English:

'Micha'

Hi,

When I compare the Pirellis on my Golf to the CEAT tires on my wife's Lupo... the Pirelli is the clear winner. By the way, CEAT is a subsidiary of Pirelli.
"On a wet road, I almost had a scare with the CEAT tires, but I have no problems on snow. The Pirelli tire is very well-balanced, performing well both on snow and on wet roads."
Yesterday, I drove up the mountain near my house, and the neighbors were staring strangely... I have no idea why. Later, I found out that I was the first person to make it up the mountain. Everyone else had given up at the point where I started driving.

Buying tires is unfortunately a gamble. Only a few tire manufacturers will refund your money if you're not satisfied. And so, you're forced to live with a bad choice for the entire lifespan of the tires.

I've had my new tires on for about a week now, specifically the Conti TS 780 in size 185. I'm really impressed with the tires!

Regarding all the discussions about tire width, it's important not to get bogged down in attempts to explain everything using only Coulomb friction. That model doesn't fully account for the phenomenon, as interlocking effects also play a significant role.

If the contact pressure is always the same, and the contact area is also the same, then a wider tire and a narrower tire would compress the snow equally, and therefore it shouldn't make a difference, right?


Cognitive bias: Consider how much wider the side of a tire is that needs to be compressed, for example, a 225 compared to a 175. The longer edge is roughly 22.5 cm versus 17.5 cm. In the contact patch, the two tires are almost identical.
That's why, when driving on deep snow, it's always best to use the narrowest possible tires to prevent 'floating' on the snow, as the tire has to compact less snow. (Think about it: try pushing a broom handle across the water horizontally versus vertically...which is easier?)

On packed snow, a wider tire might offer slightly better tracking, but I've never personally experienced or noticed a significant difference in practice.

Calculating the coefficient of friction isn't that simple; the tire engages/bites into the snow mass, and that's a product of the positive/negative ratio in the tread pattern and its structure. } Unfortunately, it's not that straightforward.

Well, I think it's difficult to make a precise statement on this topic. There are too many parameters that are not under control. We all have experience with winter tires, but factors like tire pressure, tire width, wear, type of snow, outside temperature, distance traveled, and subjective impressions... too many things interfere with a clear conclusion.

I have 16-inch winter tires from GT Radial on my Golf 205. They have never disappointed me in the winter. I was initially concerned that they might not perform well in snow, but with a gentle driving style, occasional ASR (traction control) activation, and adjusted speed, they actually feel quite good to drive. However, I get the impression that they could be better when braking on wet roads from higher speeds. As I said, this is just my subjective opinion.