Wider tyres - Will they increase braking efficiency

[badri]

Hi All,

I have recently faced a couple of scary braking situations at about 110-120 Kmph in my Accent Viva CRDI. Since there is no option of ABS, I am toying with the idea of changing to wider tyres.

Can anyone let me know what is the effect of wider tyres on braking distances, reducing the locking of tyres etc. Is it worth it or is it that the tyres are going to lock anyway with out ABS? What about the cornering grip? Will it increase with wider tyres. Right now I dont feel so confident in some corners as I would in my old opel astra 1.7 TD

[kpzen]

Its not necessary wider tyres will only increase the braking efficiency....the tyres also have to be good..........
consider same width tyres
Bridgestone S322 - Its hard like a stone n will last long...
Bridgestone GIII - Its like a glue....will give u confidence in braking n cornering but wont last as S322...

[iraghava]

KP is absolutely right the compound plays a very important part in a tyre's performance.

For your car which is currently running 175/70 R13 Bridgestone S322's (considering you haven't changed the stock tyres) you can either try a better tyre in the same size or upgrade to 185/65 R13 or 195/60 R13's.

Do also tell us what kind of a budget you're looking at for all this.

[Shan2nu]

It's the combination of width and tyre compound that gives you braking efficiency. Without ABS, wheel lock is impossible to prevent, but by increasing the contact patch, you can reduce your chances of wheel lock up (under similar conditions).

Just make sure you don't use, too big a contact patch, as that will also increase your chances of aquaplaning.

But, if someones facing probs with weak brakes, then wider tyres maynot be that helpful. You'l have to get your brakes improved first.

Shan2nu

[n_aditya]

Well i guess the Viva doesn't come with Rear Disc's. You can upgrade to rear disc brakes which can improve braking. Of course like the others have mentioned good tires are equally important.

[theMAG]

Wider the contact area, better is the handling dynamics - stability and braking.

[karthik247]

Softer compound tyres provide better grip but last less while hard compound tyres will last long but offer less grip..

Any other advantage for hard compound tyres???

[vid6639]

i guess hard compounds are less prone to cuts and gashes caused by our bad roads. The softer ones may not be and sidewall cuts may be easy.

[theexister]

Please remember that changing the size in most cases changes only contact patch shape & not the actual area of contact.
It is the compound is critical in this situation & a softer one abviously giving better grip but a lesser road life.
It is a matter of compromise.

[badri]

Hi,

My car has done 27K Kilometres and has the standard tyres. It looks like they will run another 15-20K with out any problem but I plan to change after the car does 35K ( I guess it will in another 3-4 months)> My budget would be around 20 K for 5 tyres. What do you guys suggest.

I sure would like to go in for rear discs if I can but I guess it is a bit complicated and I dont know if anyone on the forum has done the same. Any inputs?

[vezj420]

First, take a look at this informative link, which I found pretty enlightening:

The Pansy Patrol - Info for the 3000GT / Stealth Community

To summarize, brake upgrades (i.e. bigger discs, grooves, drills, etc.) are mostly for heat dissipation to reduce brake fade when brakes are being used repeatedly. It is the tyres' contact patch area (and compound I guess) that are crucial in the actual slow-down of a vehicle once the wheels lock in case of a hard stop(or modulate at that level without locking, in the case of ABS).

Rear discs may help some, but on most Indian cars, esp. with front-wheel drive (viva?), this won't make a big difference. And it's probably not worth the hassle and price. This option makes sense if you're adding vast amounts of power to your car, i.e. with a turbo/supercharger or constant NOS. Which I don't gather is the case here.

The one option that IS worth trying though (in addition to bigger tyres), is upgrading the front-discs system and any parts thereof.

Hope that helps!

[Struggly]

Badri,

Can you explain what you mean by "scary braking situations" a little more? That will help us determine if a wider tire is going to solve your "problem".

Another thing for you to think about is braking technique. If your "scary breaking situations" involved a sudden stop and the wheels locking up, you should know that your stopping distances in the dry will be shorter if you can remain calm and keep the tires from locking up.

The proper way to brake with a non-ABS car is to depress the brake pedal until the wheels are about to lock, and then to hold it there, trying to anticipate and prevent lockup. This technique is called threshold braking. It takes time to master, but once you can do it you'll find that your car stops a lot better because you have greater command of it.

Clint

[Rehaan]

Badri,

First tell us what size and tyre make and model you are currently running, this might help us point out any obvious disagvantages with your setup.

Dont waste your time thinking about rear discs and upgrading the system at the moment.

First upgrade to some higher performance tyres (Bridgestone G3's are pretty popular at the moment) and maybe go up to 185 (or 195 if you are a speed demon.)
You will probably see a very noticable advantage over the stock tyres.

If you are still not happy, then you can consider some better brake pads, and then onwards from there.

cya
R

[manveet]

Originally Posted by theexister

Please remember that changing the size in most cases changes only contact patch shape & not the actual area of contact.

I disagree.

Wider tires will obviously have a greater area of contact.

I'm not sure about the chape of contact patch, but logically speaking, that should always remain constant i.e. rectangular/square or whatever it is .. probably depends on the air pressure too.

Regards

[kpzen]

Originally Posted by Rehaan

Badri,

First tell us what size and tyre make and model you are currently running, this might help us point out any obvious disagvantages with your setup.

From what he has mentioned:

Tyres : 175/70-13 Bridgestone S322