TDI Motorenvergleich | Posts 32+

Yes, exactly.

Narrow tires already achieve a friction factor of 1 or slightly more. With wide tires made of an extremely soft rubber compound, it's possible to increase this value to 1.2. However, at that point, it's no longer primarily about the grip force; the tires are essentially sticking very firmly to the ground.
However, there is no diesel vehicle that could effectively utilize this effect. The first gear is so short, and then you only have power available for lower acceleration.
Here's the translation:

Why wider tires might still prevent wheelspin: They have more weight and a greater moment of inertia, which reduces acceleration.

'So, wide tires don't really offer much in terms of acceleration for road vehicles, but the extra fuel consumption is also relatively limited. I heard that modern wide tires actually consume less fuel, and they also offer advantages in terms of grip, even in wet conditions. The downside is that they are more expensive.'
Best regards, Ernst.

Ernst S. wrote:

Why wider tires might still prevent wheelspin: They have more weight and a greater moment of inertia, which reduces acceleration.

That's not a big deal!

Hi!

In theory, the friction shouldn't change between wide tires (larger contact area) and narrower tires, as the friction coefficient remains the same. This coefficient only depends on the load, not the area – unless you consider the interlocking effect of our rubber compounds. In reality, this means: a larger contact area equals greater grip.

Best regards,
Uwe

That's not a big deal!



How about providing the moment of inertia for comparison tires? That way, I won't have to do rough calculations all the time.

Otherwise, all these effects (slightly higher friction – which is the interlocking effect, as you say, meaning 'sticking' – plus a few kilograms of mass that are translated, and 0.x kgm² per tire in terms of rotational inertia, which needs to be accelerated, plus possibly a slightly larger radius that reduces the driving force) can lead to the situation where, for some people, wider tires no longer slip, while narrower tires might still slip.

If the term 'coefficient of friction' bothered you, the coefficient of friction defined in Coulomb's law of friction has little to do with what actually happens with a tire. That's why effects like 'interlocking' are still considered part of what is defined as the 'coefficient of friction' for a tire.
Best regards, Ernst.

Hello,

Perhaps something different: Which TDI engine would you choose? Let's say for a Golf 4.
- 90 horsepower with 210 Nm of torque.
- 100 HP PD
- 110 horsepower with 235 Nm of torque.
- 115 hp, PD (Pump Denoise) technology, 285 Nm torque, 5-speed transmission.
- 115... 310 Nm, 6-speed.
- ...

Do you really need 300 Nm? Which engine is 'the best' for you? Please don't all choose the 150 HP PD...

Best regards,

Adrian.

PS: I'm drawn to the 100 HP PD model because of its nice torque curve (it's probably my next purchase). It doesn't have that extreme peak followed by 'nothing' like the 115 HP 6-speed model.

Do you really need 300 Nm? Which engine is 'the best' for you? Please don't all choose the 150 HP PD...






In the GF forum, someone wrote about the three engine options: '...the 100 hp engine is for practicality, the 130 hp engine is for fun, and if you have enough money, you should get the 150 hp engine...' I completely agree with that.


...me too.

As long as you're driving a Golf and not a heavier Passat, 100 horsepower is already quite fun. And as Bertil described, his 100 horsepower car in his station wagon also performs quite well.
So, if you're already happy with the torque curve of the 100 model, then there's no need to think any further.
However, if you can find a G3 (lighter than the G4) with low mileage and the 110 hp AFN engine, that might also be worth considering.

Best regards, Ernst.