Thread: So, about those tyre widths

I kind'a agree(ish) with your mate, in his comment re the road going performance.
Technically tho, it's not really less safe, as safety is pretty much 99.9%(if not 100%) up to the drivers adherence to safety principles.

You can have the safest, fattest tyred car ever made, but you drive like an idiot like most Melbournians do! ... you will kill someone or die yourself trying(hard to drive like an idiot)

But I think I get your mates point tho, he's referring to the point that you have less contact patch on the road, and that ultimately equals less grip.
Once you know this and drive with this in mind, doesn't really mean that its "less safe".

ps. I like skinnier tyres more so for their safer feel on loose gravel more than anything else.
When I had my Rodeo ute, on it's skinny bike tyres it had when I got it, it was diabolical on wet tarmac.
I ended up with 10.5x15s for it to replace the 205/75 16s.
But, having driven for years on skinny tyred LR(series IIa and RRC) on many gravel roads and got the feeling for them and the way they felt, the much more modern handling Rodeo felt terrible by comparison on gravel roads around Aus.

If contact patch is a thing, I could lower (not like sand driving of course!) the tyre pressure slightly and get an equal contact patch-ish I reckon? Wet roads are of most concern that is what we ended up with as well. I never felt on dry bitumen that I needed more grip, I was more aware of the car getting tippy before I was losing grip it felt like. Thing is, most of us DO run higher tyre pressures on road since it gives better fuel economy and keeps the tyres "cool". I would go so far as to say a lot of people drive with over inflated tyres!

It is a very well spun conversation around many a camp fire, but this was the first time someone maintained I had made the safety of my car less due to thinner tyres!

-P

PS I have gravel road experience but only in the skinnies, not the wider tyres so I can't comment on that

Originally Posted by prelude

...

PS I have gravel road experience but only in the skinnies, not the wider tyres so I can't comment on that

I never got to drive the Rodeo on the 205s on gravel(changed them fairly quickly).
So my comment is really a guesstimate on feel, maybe the Rodeo was even worse on skinny tyres on gravel too, and that it may have just been all round 'loose feeling' due to its horse and cart suspension design.

It had this 'aquaplane' type feeling, like it was rolling over the looser stuff or something, where the RRC and even the IIa I remember, just felt less slippy.

But on road(bitumen) compared to the RRC, it felt like a sports car ... just a massive contrast to how different it then was on those long gravel road drives out here.

Not too long ago, I changed the tyres on the D2. I did because it had steel wheels, and I got a set of alloys for it. The alloys had very usable 265 tyres, so they went on and it still has them on.
This is the only time I've ever had the chance to directly compare skinnier vs wider tyres of similar age.
The 245 BFGs are worn about the same, maybe a tad more, but not enough to say new tyre vs old tyre misalignment of performance.

This is the problem us normal folks have. You may have 255s on, and then replace with 235s, but you might find that you feel like you have more grip than before, but you're comparing not just new tyres vs old worn stuff(huge performance) but possibly totally different performance due to brand/model of tyre.
But I can 100% say that in general driving, a lot of commuting, and a lot of that commuting through damned annoying roundabouts between home and work! .. I can say I find enough difference between 265s and 245s.

Maybe I may have 1 meter of stopping distance more with the 265s vs the 245s at their age .. maybe more .. maybe even no difference. My main point in my earlier reply is be aware of everything around you so you don't NEED to slam the brakes on hard enough to find out if that 1meter of braking advantage is there or not.

Tyre width is a very minor factor in safety compared even to other tyre dependent factors such as tread, pressure, rubber composition as long as we are talking about realistic changes. Almost the only relevant bit is that wider tyres often increase track.

Contact patch is almost a furphy, since it depends almost entirely on tyre pressure and construction, not width. Although worth pointing out that an excessively wide tyre may reduce its contact patch on corners unless the suspension is designed for it.

nothin' like a tyre tread is there?.....errrr thread?

brand can affect safety......ie resistance to blowouts.......the current good tyre of choice is Toyo, the cockys like them. The Williams Cattle Company have hundreds of them on their station vehicles.

I was speaking to a couple of different suppliers and asked them without bias what they think is currently the best a/t tyre......Toyo.

I'm just cooking the popcorn now.

@ramblingboy42 or a tiring thread?

I agree though that tyre compound etc has a bigger impact overall. Also we both agreed that stopping distance would be well within safety limits since we are not tailgaters and drive leisurely with our 4bees The only thing we could really not get our heads around is the lateral difference ie, slipping sideways. I have not found the limit to that as of yet and taking a corner at those speeds is already becoming quite uncomfortable and while I believe brake testing on an open empty road is quite safe, swerving is not something I am going to try out unless on a circuit with a professional driver or instructor...

In any case, my guess was that not the width but the height of the tyre wall was going to have more of an impact. ie, the skinnier tyres usually also have more height to them creating more flex and rolling of the tyre to the point where in theory under heavy duress ie when swerving the tyre tread would no longer entirely touch the ground but the sidewall would.

Our final conclusion was that the change from highway to muddies posed the biggest difference in performance and thus safety. At least it was a good evening

-P

Originally Posted by AK83

I kind'a agree(ish) with your mate, in his comment re the road going performance.
Technically tho, it's not really less safe, as safety is pretty much 99.9%(if not 100%) up to the drivers adherence to safety principles.

You can have the safest, fattest tyred car ever made, but you drive like an idiot like most Melbournians do! ... you will kill someone or die yourself trying(hard to drive like an idiot)

But I think I get your mates point tho, he's referring to the point that you have less contact patch on the road, and that ultimately equals less grip.
Once you know this and drive with this in mind, doesn't really mean that its "less safe".

ps. I like skinnier tyres more so for their safer feel on loose gravel more than anything else.
When I had my Rodeo ute, on it's skinny bike tyres it had when I got it, it was diabolical on wet tarmac.
I ended up with 10.5x15s for it to replace the 205/75 16s.
But, having driven for years on skinny tyred LR(series IIa and RRC) on many gravel roads and got the feeling for them and the way they felt, the much more modern handling Rodeo felt terrible by comparison on gravel roads around Aus.

Have you seen how many idiots drive BMW X5's? Have you seen how fat those rear tyres are??!!!

I went from 215 to 205 for a Courier 4x4 ute because of aquaplaning when it was really wet.

The thing is really light (like 1300 kg) and would lose contact with the bitumen even with new 215's,
but has been fine since the change.

Years ago I guy I know put 15" wide Mickey T tyres on the rear of an XA 2 door after pruning the guards.

Those tyres became expensive plant pots after the first time he drove it in the rain.

DL