This doesn’t settle the argument, but CapriRacer talks about tire treads a bit here.
If a tire manufacturer offers a dozen styles of tires they will produce tires to meet the buying public’s demand. And a trendy image is often a significant determinant of what sells. Super low profile tires on huge rims are awfully expensive and perform terribly but there are tire stores opening that sell nothing else. And I recall lowering several jacked up 4 wheel drives 30 years ago with large Dick Cepek tires that were not capable of speeds above 45 mph but they looked like the trucks seen in 4WD magazines. The owners had spent thousands to get that image but couldn’t drive their beasts past the city limits sign. Image sells. The public rushes to buy it and goes deep into debt to get it immediately.
Tire manufacturers may have great tires dry rotting in their warehouses while fashionable but much lower performing tires sell faster than they can be produced.
Beyound that, tread pattern is irrelevant
Have to disagree. Sounds to me you are only taking about mid summer tires used on race cars.
As a tire wears, it’s ability to Cope with hydro planing changes. Tread patterns can help minimize the loss, but at the expense of handing early on. How much a tire manufacturer wants to go one way or another can affect the tread pattern choice.
The shoulders of a tire will help determine the handling characteristics. A completely solid shoulder with no horizontal block separation would be ideal. Let a driver drop into a soft shoulder on the side of the road and he can easily loose control with a tire maximized for cornering on pavement. Tires have blocked treads on the shoulder to deal with that eventuality and the spaces between the blocks are always a choice the tire manufacturer makes based upon his priorities for each tire model. They have to realize too, that increasing the traction on a gravel surface could also increase the noise of the tire at speed…another compromise.
All summer tires have to be considered for some off road use. Off road capabilities can then vary depending upon the tread design.
http://www.google.co.in/patents/WO2008017569A1?cl=en
Even a load rating can affect tread design.
"What exactly do you attribute the differences in tracking, ride, cornering, and traction to? How do you explain them?"
Those are a function of carcass construction and rubber compounding. We are addressing only tread patterns here.
Sorry, but I have to disagree. Carcass and compound are definitely key ingredients, but I think you’re greatly underestimating the effects of tread design.
“…I think you’re greatly underestimating the effects of tread design pattern.”
There, I fixed it.
No problem, although I would have preferred that you line out the word “pattern” instead of “design”. “Pattern” could be interpreted to mean that it’s just decoration. “Design” implies actual testing and analysis. When taking the liberty of correcting another’s statements, you owe them the respect of being sure you’re getting it right.
I was sure I got it right.
@insighful.
Load rating is affected by tread design or pattern. Noise level is affected by tread design. Everything an automobile is used for…is affected by tread design or pattern if you will. Some subtly, some in a major way. The tire is the single most transformative piece of equipment of all cars when it comes to exploiting the capabilities a car was designed for. The tread pattern, as are other attributes, are ALL critical to balancing the performance prioities of ALL CARS AND EVERY OTHER VEHICLE THAT USES A RUBBER TIRE. I have a tractor and a choice of three general tread patterns. Each one totally transforms what I can use my tractor for…it is NO DIFFERENT FROM CARS. Small differences may not show up their different capabilities except on special occasions but larger differences do.
If tread patterns were incidental, why does everyone with any tire expertise recomend that when buying tires, they have similar tread depths and patterns as those already on the car ? Otherwise, you buy all new tires that are the same if you can’t match them
Tread Patterns, tread patterns, tread patterns. Where to start?
The biggest thing that tread patterns accomplish is wet and snow traction. However, tread patterns cause noise and vibrations - and moderating those affects can be a challenge for the tire design engineer.
You can hurt dry traction with a tread pattern.
Ride harshness is not really affected by tread pattern - as is steering crispness.
Tire grooves can also try to follow the grooves in the pavement - and that is a challenge as well.
mareakin said: “…even directional tires when I’ve mounted them backwards (forced by circumstance) I have noticed no different in handling in dry or wet…”
And that is somewhat true. You can measure the difference in traction, but the difference is small enough that it takes a trained observer (race car driver) to be able to detect and use the difference.
"If tread patterns were incidental, why does everyone with any tire expertise recomend that when buying tires, they have similar tread depths and patterns as those already on the car ? Otherwise, you buy all new tires that are the same if you can't match them "
Tread depths, sure, but I would bet you could not tell the difference on dry pavement driving a car with four identical tires, except they had four different tread patterns.
@Insightful.
But I bet you could not tell the difference on dry pavement
First we restricted it to summer tires and now to dry pavement. If we restrict it to low speed, going straight ahead on dry pavement carrying little to no extra load, are not braking or cornering, then yes…it may be harder to differentiate different tread designs. But load it a little, take a corner, drive at higher speeds…oh, and throw in recovery from a wheel dropping into a soft shoulder while traveling 45 mph, throw in wet pavement and then I can’t agree with you. If one paints the discussion “into a higly restricted corner”, ANY TIRE and probably any tread pattern will work. But that’s not real life and that is not the minimal tests of tire reviews do. Even summer performance tires have a variety of conditons they must account for. Please read any tire test from Consumer Reports and Tire Rack. They outline the varieing conditons that all tires are tested for. Even tire wear is influenced by tread design.
Btw, in the articles I have read, directional tires do tend to show little difference in many performance categories when mounted incorrectly. But they also point out that starting and stopping are two biggies that often do show a marked difference. I have directional winter tires…it’s obvious by the tread design why they can stop so well in one direction yet be functionally quiet with less drag in the other while cruising. Mounting these backwards would show dramatic differnet IMho, in stopping. The same, I feel, would be true for most directional all season tires too.
"Btw, in the articles I have read, directional tires do tend to show little difference in many performance categories when mounted incorrectly."
Thank you; that’s my point in a nutshell.
Please read the entire response. But they also point out that stopping and starting are two biggies they often show a marked difference
The categories where there seemed to be little difference are wear, noise and cornering. Where there was a significant difference was a biggy STOPPING DIFFERENCE and acceleration. That one characteristic is enough to make anyone more carful when mounting them.
"Where there was a significant difference was a biggy STOPPING DIFFERENCE and acceleration."
I doubt it it was a big difference. Please show the data.
From a tire expert (Barry's Tire Tech):
"If you mount a directional tire backwards - so that it is rotating the wrong direction - the only problem caused is wet (or snow) traction. It does not affect wear, pull, dry traction, ride, or any other characteristics. If you have one of those problems, then the problem has nothing to do with the direction of rotation of the tires."
http://barrystiretech.com/directionalandasymmetricaltires.html
http://www.goodyear.com/email/faq/mounting.html
So I am using the same reference to say what I ALWAYS SAID. Mounting directional tires affects rotational traction. Now, you want just talk about dry traction to prove yourself right about what…that cars only drive on dry pavement ? Rotational traction is a huge factor for wet, snow and gravel, two of which ALL tires encounter.
I say the difference is significant because TIRE MAKERS SAY YOU SHOULD NOT MOUNT THEM BACKWARDS. obviously, they think so too. The last time I looked, stopping distance and acceleration were rational traction functions.
This does a good job of explaining it.
I guess we could play this game for a while as you miss quote or only selectively use someone’s statements. But the fact remains, directional tires though tire specific perfom SIGNIFICAMTLY better when mounted in the intended direction. And starting and stopping is significant.
And while dagosa and Insightful can argue their points for quite sometime because neither has access to real testing data - and I can’t add anything to help them sort out their differences because I don’t either, I do want address an earlier post:
dagosa said: “…Load rating is affected by tread design or pattern…”
Sorry, no.
Load Rating (and I assume you meant Load Carrying Capacity), is a function of size and inflation pressure. If you count the letters before and after the numbers in the size as part of the “size” (those letters indicate the type of service the tire was designed for), then there are load tables that call out the load carrying capacity by size and inflation pressure - and nothing else. The tread pattern does not affect the load carrying capacity.
But if you meant Load Range or Load Index, then, again, those are indicators of the MAX load carrying capacity for a given size (including the letters), and tread pattern has no affect here.
@CapriRacer The tires designed to take heavier loads necessarily have different tread designs then those that don’t on most high capacity vehicles. Look at all higher rated tires on trucks and high capacity SUVS. In a lightly loaded passenger car where you seldom reach the rated limit of the specialized tread pattern , you might never be concerned. But, on an SUV or truck you may use for carrying heavier weights and tow as you approach the limt, the tread design has a significant impact, not only on how much weight you can travel at higher speeds, but cornering, braking etc, ; the deficiencies are all multiplied by inappropriate tread design for the task at hand.
Appropriate tread design can reduce squirm which can add to heat build up caused by heavier loads. They all interact and practical load carrying and their ratings often differ because of this.
For example, when we go to traction tires on our sand truck or any SUV or vehicle that we plan on carrying heavier weights, we go to a HIGHER rated (load carrying capacity ) tire then commonly used to compensate for the deficiencies of these tires with compromised tread patterns. That means, if you routinly drive a car loaded with commuters and you run at near the capacity of your specialized tires, you might consider going to a higher rated tire.
Or…like many, you should at least, drive much slower and load the vehicle to lower then it’s rated capacity then you would for a non specialized tread design that came with the vehicle. with the same rating.
Plus, these ratings are not isolated. You may see a specialized tread pattern with the same load rating ( load index) but a lower speed rating. That is an acknowledgement that the vehicle with these tires cannot carry the rated load at the normal higher speeds. That is practicality. Does it have something to do with the rubber compound ? Perhaps…but it also has to do with the tread pattern, squirm and heat build up.
I think that CapriRacer is privy to a lot more tire testing information than the rest of us could even dream of.
It would seem to me that if tread design had anything to do with load rating it would be specified by the tire manufacturers.
In other words, if that Ford Ranger is just going to be used for scooting around town one tread design would be recommended and if the Ranger was going to be used as a highway load hauler another tread design would be specced. I just don’t see that at all.