Drifting

[Lucke]

I started to notice that sometimes my truck begins to drift at the slightest turn, but other times, I can't drift to save my life. Does anyone know what determines how/when/why the truck drifts? Is it trailer weight? Wheel Condition? Chassis type?

[Knottypine]

If I were to guess, I'd just say... too fast around corners, and turning too sharply.

[Lucke]

I would exit highways at 55MPH without drifting (well, at least I couldn't tell if I was lol), but now, any turn of the wheel, no matter how slight seems to make me drift. It's not consistant either. Some turns I'll drift and others I won't. I have noticed that going faster taking a sharp turn will make me drift, but I would take that same corner and not drift the next time.

[Jᴧgᴧ]

Mods? Damage to chassis or wheels?

[zbobg]

The physics for trailers seems to have changed with the v1.3 patch.

Heavier shorter trailers are now more difficult to pull, they make your truck less stable. The most non-stable trailer is the sand/coal/gravel hopper.

Two factors contribute to instability, the mass and length of the trailer. The center of mass of the shorter trailers is closer to the center of mass of the cab, this causes greater instability than a longer trailer. Having the trailer center of mass closer to the cab center of mass results in larger angular momentum (given that other factors are the same) sooner that a longer trailer, this makes the truck/trailer more likely to spin or drift.

None of the above is wrong or buggy although it may be just a little bit exaggerated by the game engine.

[jfhopkin]

I think you're also more likely to drift when the road surface is wet - during rain or for a short while afterwards.

[Lucke]

So, you're saying that longer and heavier trailers drift less and shorter trailers drift more?

But what about the weight then? Heavier loads drift less or weight makes little difference?

[Davemented]

The chassis makes a big difference. The 6x2-4 and 6x4 chassis are much more stable and less prone to drifting than the standard 4x2.

[zbobg]

You might think that heavier loads would drift less, there is more force on the tires giving higher friction making it less likely that the trailer would drift. Sadly, tire forces seem to be static so none of that makes any difference.

Heavier trailers are less stable than lighter trailers.

Shorter trailers are less stable than longer trailers.

Therefore:
1. Heavier shorter trailers are most unstable.
2. Light long trailers are most stable.
3. Heavy long trailers fall in the middle.

The effect of the chassis, 4x2 vs 6x4, is probably mostly due to one factor. The 6x4 chassis is longer (considering the trailer attachment point) than the 4x2 chassis. This gives a larger distance between the center of mass of the cab and the center of mass of the trailer leading to greater stability. The Mercedes 6x4 and MAN 6x4 cabs have the longest wheelbase and would therefore be most stable, not specifically because of the wheelbase (although that probably has some effect) but because of the separation of the centers of mass.

It is possible the the greater number of tires makes a difference, it would make a big difference in the real world, but I can't find any evidence that the game models that effect. The game engine might do that as well though.

[City Builder]

Originally posted by jfhopkin:

I think you're also more likely to drift when the road surface is wet - during rain or for a short while afterwards.

Wait, did the 1.3 update actually do anything to rain or water physics? I was/am under the impression that rain is still just a visual eye candy and nothing more.

[Rumpelcrutchskin]

Speed, chassis, weight of the trailer. Heavy trailer is more prone to drifting. Also each truck has their own character and limit what it can take, for instance Mercedes is much more stable then Volvo. Even with 6x4 chassis some trucks are much shorter then others.

[Paul Debrion]

I've had some rather scary skidding incidents even before the 1.3 update that did seem to be related to rain.

I can't say with 100% certainty that it was the rain but so far I've lost control of the truck about five times due to sliding while it was raining and I haven't had it happen even once while it was dry, so that seems to suggest the rain does do something.

[jfhopkin]

What ProfessorPaul1290 said.

I've no hard evidence, but I've had several occasions when I've thought "why on Earth did I lose control there? Ah yes, the road was wet." And yes, I agree that it predates the 1.3 update.

[nirwana]

Pulling 45t+ trailers now my front wheels sometimes hang literally in the air (8| ...