[freewheelburnin]

I was searching for S.U.V safe driving tips and found this interesting article
How to Drive Your SUV
(Courtesy suvdriving.net)
Please add your discussions,comments and tips on Safer S.U.V driving practices

[Shan2nu]

I not sure if the hand positions they have recomended are safe.

http://www.suvdriving.net/a.jpg

http://www.suvdriving.net/b.jpg

I prefer the racing hand position as it lets you react much faster and get back to your original position without much confusion.

Some SUV's and 4 x 4s can be rolled by steering wheel turns in excess of 120 degrees. (1/3 turn). Many serious rollover accidents have been caused by incidents of excessive steering.

Again, this is not totally dependant on steering rotation. Its a combination of vehicle speed and rate of change of direction that can unsettle an SUV (which again differs with every vehicle).

Another thing that i always do is to finish my braking before i start turning for a corner. While this is common knowledge on a race track, i have noticed many of my friends and relatives continue barking even as they are cornering.

Shan2nu

[freewheelburnin]

I found this line in the article
"But tires which are operated at the maximum pressure tend to have reduced contact area and thus produce less cornering force which is good for SUV's and 4 x 4s"
Is it true that wider tires will produce more cornering force and hence cause the vehicle to topple, but lesser contact area and harder tires with more air filled will oversteer and prevent toppling?If this is true what would be the advantage of wider tyres?

[freewheelburnin]

That is the whole idea ...a fast input to SUV steering can upset the vehicle's dynamics.So is it not better to do more predictive driving rather than instantaneous changes?A fast turning of steering on seeing an obstacle is a reflex action and could prove fatal in an S.U.V.

Originally Posted by Shan2nu

I not sure if the hand positions they have recomended are safe.

http://www.suvdriving.net/a.jpg

http://www.suvdriving.net/b.jpg

I prefer the racing hand position as it lets you react much faster and get back to your original position without much confusion.



Again, this is not totally dependant on steering rotation. Its a combination of vehicle speed and rate of change of direction that can unsettle an SUV (which again differs with every vehicle).

Shan2nu

[Shan2nu]

That is the whole idea ...a fast input to SUV steering can upset the vehicle's dynamics.So is it not better to do more predictive driving rather than instantaneous changes?

This surely wont work on indian roads. Here you have to be a Sabastien Loeb at every damn corner. LOL

I found this line in the article
"But tires which are operated at the maximum pressure tend to have reduced contact area and thus produce less cornering force which is good for SUV's and 4 x 4s"
Is it true that wider tires will produce more cornering force and hence cause the vehicle to topple, but lesser contact area and harder tires with more air filled will oversteer and prevent toppling?If this is true what would be the advantage of wider tyres?

Its true but its not safe. Higher tyre pressure reduces contact area and also cuts down on tyre flex. So a vehicle will lose traction before it reaches its rollover threshold.

On the downside, you will face a drop in braking traction.

Shan2nu

[freewheelburnin]

Yes that would be even more disastrous if braking is lost....Probably more dangerous than a rollover

Originally Posted by Shan2nu

This surely wont work on indian roads. Here you have to be a Sabastien Loeb at every damn corner. LOL



Its true but its not safe. Higher tyre pressure reduces contact area and also cuts down on tyre flex. So a vehicle will lose traction before it reaches its rollover threshold.
On the downside, you will face a drop in braking traction.

Shan2nu

[Shan2nu]

Heres a diagram showing how contact area is affected with tyre pressure.

http://www.kidsfriendlynz.com/inflated-tyres.jpg

Shan2nu

[freewheelburnin]

In that case is it not better to stick to stock tyres rather than going for wider tyres?Wider tyres would improve braking but at the cost of cornering.But wouldnt a stock tyre with slightly reduced pressure provide the best of both worlds?

[headers]

Originally Posted by Shan2nu

I prefer the racing hand position as it lets you react much faster and get back to your original position without much confusion.

..
Another thing that i always do is to finish my braking before i start turning for a corner. While this is common knowledge on a race track, i have noticed many of my friends and relatives continue barking even as they are cornering.

Shan2nu

+100 to you. Great minds think alike!

Originally Posted by hrag

Is it not easier to drive and get a feel of the SUV than to go through some article and invite comments from keyboard warriors?

LOL Hrishi, you are the MAN to tell us from your experience!

[Shan2nu]

In that case is it not better to stick to stock tyres rather than going for wider tyres?Wider tyres would improve braking but at the cost of cornering.But wouldnt a stock tyre with slightly reduced pressure provide the best of both worlds?

Depends on what tyres the manufacturer has provided. If they are of good quality and provide sufficiant traction, then there is not need to upgrade.

But some car come is tyres that dont matchup with the performance of the car. In such cases and upgrade is needed.

Shan2nu

[Shan2nu]

Another thing that i always do is to finish my braking before i start turning for a corner. While this is common knowledge on a race track, i have noticed many of my friends and relatives continue barking even as they are cornering.

Haha, i just realised i typed "barking" instead of "braking". Can the mods please correct it and delete this post.

Shan2nu

[Shan2nu]

End of the day, no matter what tyres you have or what the surface conditions are like, all it takes is an idiot behind the wheel. Hehe

YouTube - car crash with surfboards

Shan2nu

[freewheelburnin]

You said it , the idiot behind the wheel can override any safety technology!! The video is hilarious!

Originally Posted by Shan2nu

End of the day, no matter what tyres you have or what the surface conditions are like, all it takes is an idiot behind the wheel. Hehe

YouTube - car crash with surfboards

Shan2nu

[watashi75]

Originally Posted by freewheelburnin

I found this line in the article
"But tires which are operated at the maximum pressure tend to have reduced contact area and thus produce less cornering force which is good for SUV's and 4 x 4s"
Is it true that wider tires will produce more cornering force and hence cause the vehicle to topple, but lesser contact area and harder tires with more air filled will oversteer and prevent toppling?If this is true what would be the advantage of wider tyres?

Just to clarify a couple of myths here -

Myth 1: wider tyres = more contact area

Myth 2: more contact patch = more grip

Reference: Browser Warning

Most of the misconception arises because people also opt for better rubber when they upgrade to wider tyres.

Wider tyres do not provide any additional grip in straightline acceleration or braking. Cornering grip is different. Cornering force depends on the ability of the rubber to deform, producing what is called slip angle.

Reference: Definition of tyre Slip Angle

Wider tyres have a shorter contact patch which means there is less tread deformation for a given force (less slip angle). This leads to better cornering grip.

Reference: Chosing A Tire | Build A Faster Car

So, to answer your question, wider tires will produce more cornering force and hence cause the vehicle to topple, but for reasons other than contact patch or tyre pressure.

[MudMover]

On my weekly trips to TN I've often been involved in 'tight situations' with other SUVs on the B'lore-Mysore highway. I've noticed the following bad habits among most SUV owners/drivers:

1.Over-dependence/over-use of brakes: constant use of wheel brakes instead of using engine-braking, steering-braking, roadsurface-braking. SUVs are huge things, and it's dangerous to rely only on the wheel brakes alone to slow/stop these monsters.
2.Poor gearing judgement: I've seen a lot of uncles desperately trying to push their beasts up a hill in the 4th or 5th whereas they should've downed into the 3rd. Such 'ducks' then lose energy near the top of the hill and invariably end up neck-to-neck with some auto/tractor/scooter, thus blocking trailing traffic.
3.The small-car mentality: a couple of SUV owners like myself are erstwhile small-car owners . Such folk tend to slow/brake or take wild evasion actions even for small speedbreakers/potholes not realising that SUVs are built to take on such things in their stride and not realising that there's somebody behind them coming at high speeds.
4.Poor concentration levels: SUVs are huge things which require good driving skills> good driving skills require good concentration. I've seen a lot of SUV drivers who're smoking, talking business with the co-driver, playing with the bachcha party - all while thundering across the countryside at 100+ kmph. That's a definite OUCH! scenario.

Much of the above maybe repetitive, but these are some things I've learned by 'driving and getting the feel' of things like hrag mentioned.