Oversteer in FWD in Rain - Need Help

Lneddkelly on 02/04/2024 - 13:28
Last edited 02/04/2024 - 13:37 by 1 other user

Hi OzMechanics,

I have an Audi A4 2007 1.8T, not Quattro, and today my car started to spin when turning right in before going into freeway in wet conditions.

When turning right into freeway after the traffic light, the car started to skid (head to the right, rear spins around) in the middle of the apex. I reduced the speed from 60 to 30 and my turning speed was around 30 km/h, front wheel grips perfectly, rear wheel loses control. My tyres thread is good and pressure of the four tyres was normal.

Front: 2 x Michelin PS4 235/45/17
Rear: 2 x Toyo eco tyres

I had this experience on roundabouts 2 times before slightly, but I can feel it.

I find those white lines quite slippery when wet, is this could be a factor as well?

What should I do to avoid this happening again?

• 1
• 2

• 

  wkaxon on 04/04/2024 - 00:10

  skill issue

• 

  gtech on 04/04/2024 - 00:31

  No expert here but sounds like you are not driving fast enough …… It's really simple math ……The slower you go the more exposure to the risk ….. The faster you go the lest exposure this equates to less risk …. It's like that you tube video on savings and investing ….. Everybody should know that ;-)

  • 

    Euphemistic on 04/04/2024 - 08:19

    In terms of risk, both are high. Its the likelihood and consequences that determines the risk.

• 

  apple2016 on 04/04/2024 - 01:45

  I am not sure how your rear wheels loose traction when they are not powered by Quattro!
  If your rear tyres are spinning faster (can happen only when accelerating) and making you fish tail , they are powered. This means you have Quattro. The other way is if they are skidding ( can happen only when slowing down), you need to replace the tyres.

  • 

    Euphemistic on 04/04/2024 - 08:20

    +1

    Have you mot read the thread? Have you not driven a FWD vehicle? Lift off oversteer is a thing, in this case exacerbated by low grip tyres on thw rear.

• 

  figarow on 04/04/2024 - 09:02

  L platers

• 

  SanguinarySeraph on 04/04/2024 - 10:47

  +2

  There's a few things going on here, that have been mostly covered by others.

  Your driving technique is the primary issue
  1. You're taking too much speed for the conditions which is what is instigating the problems you're experiencing.
  2. You're lifting off/backing off the throttle too sharply at the apex which causes a weight transfer forward, significantly increasing front end grip, and reducing rear end grip) and effectively causing the rear to overtake the front which is what you're experiencing as oversteer - this can be addressed by smoother inputs, and just less initial speed. If you're accelerating on to a freeway onramp or roundabout, you shouldn't have any need to brake at all, just accelerate up to your cornering speed (30kmh for example) and then accelerate out of the corner (and/or down the ramp).
  3. Don't drive on the painted lines, rather obviously they are much smoother than asphalt and can be slippery when wet

  Your tyres aren't specifically the cause of the issue, but you could make changes which will help - however this is kind of creating a crutch to enable poor driving.
  1. You have performance tyres on the front, and eco tyres on the rear, even with good wear, there will be a pretty significant mismatch in the grip levels which will highlight issues above. It's fairly commonplace these days to actually put new tyres on the rear of FWD cars specifically for this reason, because inexperienced drivers generally can handle slight understeer much better than lift off oversteer
  2. Put PS4s on the rear as well as the fronts and you should find the car more balanced in general and provide a mechanical solution allowing you higher grip levels. However this will just mask poor technique and give you a higher threshold before issues are noticeable, which can just be false confidence.

  If you're serious about making things better, go do a defensive/advanced driver training course, AND get PS4s for the rear of your car too.

• 

  The Hawk on 04/04/2024 - 11:01

  +1

  I've done this one time when younger in a FWD vehicle going waaaay too fast into a corner being a d!ckhead in my younger days. Took the same car on a track and didn't have the same experience and I suspect it was something on the road the first time. In short, learn the limits of your car.

  Defensive driving courses are great, but even an open track day can be wild fun and give you that experience, although isn't for everyone since there are other cars and you risk damage to your own vehicle.

• 

  ElusivePotato89 on 04/04/2024 - 12:50

  +2

  It's pretty obvious mate - the grip levels between the PS4 and Toyo's are massive, and compounded more in the rain.

  The PS4 has some of the best wet grip you can buy in a tyre today - you're going at a speed that the PS4 can handle, but the Eco Toyo's can't. And the result is your rear spins out on a FWD car.

• 

  Davo1111 on 04/04/2024 - 14:14

  A lot of hate for someone asking for genuine advice, not trying to be hard. "I have a gtr and I keep drifting"

  Check tyre pressures with a better device (go off the tyre manufacturer), upgrade rear tyres when ready. In the mean time drive slower.

  I can't really give you crap for your car choice as it has 20% more HP than my chicks car

  Good on you for trying to be proactive.

• 

  freddofrog42 on 04/04/2024 - 15:03

  Manufacturers will setup nearly all modern cars to understeer - it's generally safer for the average driver. I.e. the front slides out, you lift off and the front comes back to you again. This applies to RWD and SUVs as well, sometimes through tyres pressures but often antiroll bars, roll centres et al.

  Unfortunately you have radically different tyres which won't help and I assume you lifted off qui8kly which won't happen either. That combined with weight transfer will see a FWD
  car tend to oversteer in such circumstances.

  In the days of the French hot hatches e.g. 205, 306, 106 and even the 405 they were setup far more neutrally. Great for drivers but not the hedges… Still some of the best handling FWD cars out there to this day. It's no coincidence that Peugeot made their own dampers (shocks) back then.

• 

  doobey1231 on 11/04/2024 - 09:51

  Simply going too fast around the corner, also check the age of your tyres, the older the rubber the harder it becomes. I never run older than 6 years or so.

• 

  Rally Dave on 11/04/2024 - 15:57

  Eco tyres and driving style is the issue. Change the rear tyres to something designed for grip and not mileage.
  Go find some dirt somewhere or join a local car club and learn to throw the car around. If you back of in a front wheel drive car, the rear forces still going ahead while the front is slowing down cause it to spin. In rallying, you use that to an advantage which makes front wheel drive cars actually quicker on dirt for the same sort of power in a tight and twisty road.
  Regardless of what others have said, you can break in a corner but do not jab at it. Breaking gently in a front wheel drive car is good, but this is before you lose rear traction. After that, you actually need to apply throttle to keep the front ahead of the rear. Hence, you should go out and learn to drive aggressively so you can be safe when needed to and not drive aggressively on the road. People in Australia generally do not know how to drive a car properly. They can put around the streets but are not educated far in driving so you are not alone. This is not about racing, it is about knowing what to do in a car when something happens and how to deal with different conditions.

• 

  Bretttick on 25/04/2024 - 00:20

  There are many reasons why this can happen.

  1- all road surfaces are different, if it's that same particular spot go slower when it's wet. Unfortunately some corners/roads are like ice when wet

  2- could be there was something on the road (oil, coolant, Diesel etc) the road is very slippery when it starts raining, after a while the contaminates from the road will wash away.

  3- front tyres are a big factor, to check your tyres are good turn the wheel full lock to one side and look on the inside of the tyre (do both sides). Most people look at the outer tread which is a terrible indication

  4-fwd cars will Understeer, I can't be bothered going into it technically. But here's a quick run down.

  Fwd, going to fast or losing traction will cause the car to go straight when turning or go out to the curb.

  Rwd, lose of traction will cause the rear to break out Just like drifting.

  Awd, not sure as I've go in hot into many road abouts and corners in the wet. It's like driving on rails. Never had any lose of traction.

  Driver skill is also a very big factor

• 

  Bretttick on 25/04/2024 - 00:31

  https://youtu.be/EwmDdMzzDjY

• 1
• 2