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Old 10th May 2009, 00:35   #61
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Originally Posted by Ravveendrra View Post
there are very strong cross winds (the hills act as funnels), the surface has many irregularities and there are generous dollops of grease/oil spotting it.
I completely agree with those reasons.

I had occasion to drive through a nor'wester on an open highway in WB last Sunday (http://www.team-bhp.com/forum/travel...26-nh-2-a.html), in gale force crosswinds and pouring rain (80-100 km/h windspeeds reported in the news). And what a sensation that was! The fully loaded car (Accent, 5 adults) swayed, drifted across the highway, and felt like it was floating on the road!
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Old 24th July 2009, 11:05   #62
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Default thanks all , i will keep speed under check

Hi All ,

Thank a lot all you wonderful people here. After reading all your opinions i have now made a note that this car may not be always safe for anythin above 100kms/hr. Our life and copassegers life is more than important than anything else so now i have taken " kasam" not to cross the line. thank you very much and enjoy the drive and be safe

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Originally Posted by SS-Traveller View Post
I completely agree with those reasons.

I had occasion to drive through a nor'wester on an open highway in WB last Sunday (http://www.team-bhp.com/forum/travel...26-nh-2-a.html), in gale force crosswinds and pouring rain (80-100 km/h windspeeds reported in the news). And what a sensation that was! The fully loaded car (Accent, 5 adults) swayed, drifted across the highway, and felt like it was floating on the road!
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Old 29th July 2009, 20:45   #63
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Originally Posted by Rehaan View Post
Absolutely.

If you ever park your car on the side of a highway (or any fast road) - everytime a bus or large vehicle goes by at speed you can clearly see your car shake from side to side. Same applies when in movement.

cya
R
The Bernoulli principle. The car should get actually pulled towards the larger vehicle, because of the low pressure of the air created between the two vehicles.

The shaking of the car is probably because the driver would instinctively try tosteer the vehicle the other way to avoid the movement towards the truck.
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Old 29th July 2009, 20:54   #64
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You need to check your tyre pressure as well, if its overinflated you will get the same feeling.
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Old 1st August 2009, 12:41   #65
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Just my 2 cents as someone who regularly does runs between Mumbai and Pune - The expressway definitely has rough patches and an uneven surface, high speed driving (anything above 120 kmph) is somewhat risky especially in places with strong crosswinds.

In the rainy seasons, the situation is worsened due to the massive downpour, I would recommend keeping well below 120 kmph during the rain. You would also be able to notice the areas with strong crosswinds when you see something like a wall of rain just rushing across the road.

Even when it's dry, it's really easy to sway a little and feel out of control as there are patches which are extremely slippery - maybe due to the compound used for surfacing or due to wear and tear, I'm not an expert on this so can't say (you can see these patches on a particularly sunny day when some areas on the expressway seem to shine almost like a mirror). Sliding a little in these areas is normal - nothing wrong with the car, just a factor of grip. If you try and make even small changes in direction at those speeds in these patches (including getting out of your lane to overtake another vehicle) we increase the chances of losing grip.
The solution to this is as simple as being cautious and keeping your distance. If you do feel that the car is losing grip, I would recommend slowing down and moving to the middle or left most lane for some time and enjoy the nice view

In the rainy season whenever I feel the car is sliding a little too much, I just let the car steer itself - keep the car in lane, steering straight and corrections from my side to an absolute minimum (just a light touch on the steering here and there, I don't grip the wheel hard).
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Old 16th June 2011, 19:49   #66
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Default Re: Why did my Fiesta sway on the Expressway ?

On my recent trip to Anantpur AP, just Yesterday in fact, via NH 7, I felt the same at high speeds,though it was never felt anytime before...on my highway trips..! The vehicle is Octavia vRS.

I have a question-

One of my tyre is of different tread,though the same dimensions as the other three,could the swaying be because of this?

I also noticed strong cross winds en route,though I have my doubts that the culprit would be this.

Can anybody throw some light?
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Old 16th June 2011, 20:28   #67
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Default Re: Why did my Fiesta sway on the Expressway ?

Firstly, 150kmph is a risky speed to be touching constantly. I have experienced strong cross winds making my Palio nervous on the Kolhapur highway, & the Palio is a very heavy car.
There could be a number of variants that caused the sway, just remember one thing when you decide to rip the car, only drive at the speeds that you are comfortable at & can control to an extent.
I have experienced high speeds on the USA highways, but then again, their roads are well laid out (mainly straight) & their cars have the safety assists (abs, traction control) as standard.
Take care guys, the highways are not race tracks.
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Old 17th June 2011, 11:50   #68
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Default Re: Why did my Fiesta sway on the Expressway ?

Quote:
Originally Posted by aditbelw View Post
One of my tyre is of different tread,though the same dimensions as the other three,could the swaying be because of this?

I also noticed strong cross winds en route,though I have my doubts that the culprit would be this.
Was there any water on the road? Even a thin layer of it? If yes then you probably experienced momentary aquaplaning. And the effect might have been more pronounced because your tires have different tread patterns.

The amount of water displaced by a tyre depends on its tread pattern. If one of your tires has a different tread, it's basically displacing water faster/slower than the other tires. Your car will pull to a side in such a case.
It's not safe to run tires with different tread patterns. Especially in areas prone to wet weather. Please correct this.
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Old 17th June 2011, 12:11   #69
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Default Re: Why did my Fiesta sway on the Expressway ?

[quote=niranjanrvce;2395255]Was there any water on the road? Even a thin layer of it? If yes then you probably experienced momentary aquaplaning. And the effect might have been more pronounced because your tires have different tread patterns.
---------------------------------------------------------------


The road was very Dry, and no sign of wetness at all. When I stepped out of the vehicle, to click some photographs, the winds were strong enough,to give me a new hairstyle, but then , is it possible that it can make a heavy car sway like that?

Should, I really go in for the tyre change? What other adverse effect can it have?
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Old 17th June 2011, 12:24   #70
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Default Re: Why did my Fiesta sway on the Expressway ?

Quote:
Originally Posted by aditbelw View Post
the winds were strong enough,to give me a new hairstyle, but then , is it possible that it can make a heavy car sway like that?
Oh yes. Strong cross winds can throw a fully loaded bus out of line. The actual effect depends on the direction and speed of the wind, the terrain and the speed at which you are traveling. At high speeds, the effect is much much more pronounced.

Quote:
Originally Posted by aditbelw View Post
Should, I really go in for the tyre change? What other adverse effect can it have?
What pattern is your spare tyre? If it's the same as your three tires then use that instead and keep your odd man out tyre as the spare. Your current setup shouldn't be a problem in dry weather but in a wet road+high speed scenario, I think it adds a bit of a risk. I hope they are at least the same directional tires.
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Old 17th June 2011, 12:40   #71
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Default Re: Why did my Fiesta sway on the Expressway ?

This is definitely crosswinds and they can get strong on the expressway and it does get scary, in my OHC its a cue to slow down. I have especially felt it in the Pune-Mumbai stretch before Lonavala. When the car tramlines you feel it in the steering. I am sure the heavier cars will manage better here.

Driving fast constantly on the expressway is a very bad idea, just last week on a high speed bend just before Sinhgad institute towards Mumbai the entire fast lane high speed bend was alarmingly full of mud just at the turn so there is no way you can see it untill you hit the bend!

imagine doing even 100 on that, I barely managed to survive that and instantly called the expressway authorities. Even on a BMW with all stability gadgets you are not going to escape a huge slide on something like that. An occasional burst in full visibility is ok but given the nature of things that happening lately like wandering cows, humans, lane closures, stretches with mud it will be rash.
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Old 17th June 2011, 12:51   #72
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Default Re: Why did my Fiesta sway on the Expressway ?

I experienced the same when took my ANHC to 160 kmph too! The winds push the car a little out of track and the reaction of the car causes the car to sway in either direction I assumed. But ANHC wasn't unsettled or din't feel nervous, but it lost the composure and my confidence took a beating, thus I eventually backed off
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Old 17th June 2011, 15:11   #73
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Default Re: Why did my Fiesta sway on the Expressway ?

[quote=aditbelw;2395289]
Quote:
Originally Posted by niranjanrvce View Post
Was there any water on the road? Even a thin layer of it? If yes then you probably experienced momentary aquaplaning. And the effect might have been more pronounced because your tires have different tread patterns.
---------------------------------------------------------------


The road was very Dry, and no sign of wetness at all. When I stepped out of the vehicle, to click some photographs, the winds were strong enough,to give me a new hairstyle, but then , is it possible that it can make a heavy car sway like that?

Should, I really go in for the tyre change? What other adverse effect can it have?
It not only is possible - it is almost guaranteed.

Let me give you an example you are very familiar with (but probably never noticed) - the front door of your house. If you take it off the hinges - can you lift it?

Now can you turn it while it is on hinges? I think you nodded yes - but not so quick - can you turn it by applying pressure about 1 inch away from the hinges?



It is not merely about how strong the forces are but also about how those forces are being applied. Rolling friction of tyres is much much less than sliding friction - gusts work against the first - the second they can not budge.
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Old 17th June 2011, 16:48   #74
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Default Re: Why did my Fiesta sway on the Expressway ?

Quote:
Originally Posted by amolathalye View Post
hi all ,

I was driving my fiesta 1.6 sxi ( 1000 kms on odo) on mumbai pune expressway at arppx. 150 kms/hr. All was ok and car was stable but suddenly it swayed by few inches in both directions out of my control and without any notice. I was scared to death and urgently took my foot off the accelerator. Then mantained 120 kms / hr or lesser and it peformed well. Can anybody help me on this ? the road was good and all other cars were at higher speeds , i am not sure what happened , is 150 kms / hr. too much for fiesta or i need wheel balancing or alignment ? i really really would appreciate if somebody could help here , thanks guys !

regards

amol
Hi,

As others have already pointed out, this is caused by cross winds and hence no need to worry. I have experienced this in many cars - Alto, Fiesta, Aveo, Indica etc. Reduce the speed if you encounter such an issue. Also, if you happen to drive through a pool of water on the highway at high speed, the car will tend to float.

Regards,

Pramod
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Old 17th June 2011, 17:09   #75
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Default Re: Why did my Fiesta sway on the Expressway ?

What pattern is your spare tyre? If it's the same as your three tires then use that instead and keep your odd man out tyre as the spare. Your current setup shouldn't be a problem in dry weather but in a wet road+high speed scenario, I think it adds a bit of a risk. I hope they are at least the same directional tires.[/quote]


The odd one here is the spare tyre. The original was damaged when a scooter fell on it,damaging the side wall completely. The pattern is asymmetrical with all.

I get the point ,on using the present setup on wet roads..!
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