Discussion
Why hasn't someone set up / developed a scientific test for this? Actually, I imagine they have. Rephrase.
Why don't the popular magazine tests actually set up and run standardised tests for different tyres? Pretty much all of them rely on a human element which is a huge variable when testing.
It can't be that hard to set up a robotic vehicle.
Test 1 - constant radius. You can accurately measure speed at which a tyre loses grip and then a yaw sensor or G-force meter to measure speed of lateral acceleration. This gives a scientific and accurte measure of grip (wet and dry) and progression of release of each tyre.
Test 2 - straight line with a decibel meter. Pretty accurate road noise comparison
Test 3 - Braking. Have an eletronic trigger. Sensors can measure stopping distance and G-forces. Wet and dry. There should be a direct correlation between Test 3 and Test 1.
Having a driver, even if its the same driver and the same car and the same track, is just too big a variable in my opinion.
Am I missing something here?
Why don't the popular magazine tests actually set up and run standardised tests for different tyres? Pretty much all of them rely on a human element which is a huge variable when testing.
It can't be that hard to set up a robotic vehicle.
Test 1 - constant radius. You can accurately measure speed at which a tyre loses grip and then a yaw sensor or G-force meter to measure speed of lateral acceleration. This gives a scientific and accurte measure of grip (wet and dry) and progression of release of each tyre.
Test 2 - straight line with a decibel meter. Pretty accurate road noise comparison
Test 3 - Braking. Have an eletronic trigger. Sensors can measure stopping distance and G-forces. Wet and dry. There should be a direct correlation between Test 3 and Test 1.
Having a driver, even if its the same driver and the same car and the same track, is just too big a variable in my opinion.
Am I missing something here?
They would react differently on different cars with different weights, driven wheels etc. Testing tyres on one car is only of very limited use. Subjective tests are often better as a tyre may be superior but can feel better so can be pushed harder. For example, i have Kumhos on the Golf which are not the best tyre in the world but they can be leaned on and are evry predictable. on the other hand, I've had "good tyres" which cause sphincter fluctuation even in damp conditions.
http://www.evo.co.uk/search/?words=tyre&search...
Plus recent hatch tyre test which IIRC continental won.
Plus recent hatch tyre test which IIRC continental won.
I saw the EVO test. My whole point is that, although as standardised as possible, there's still a massive margin for human error in such tests.
eg Braking from 60mph to rest. Initially you're travelling at 1.5ft every second. Therfore if the driver brakes half a second sooner or later, you're going to make a measurable difference to the outcome of each test. And I expect 15cm is quite a big distance if you manage to stop 5 cm before hitting a toddler.
eg Braking from 60mph to rest. Initially you're travelling at 1.5ft every second. Therfore if the driver brakes half a second sooner or later, you're going to make a measurable difference to the outcome of each test. And I expect 15cm is quite a big distance if you manage to stop 5 cm before hitting a toddler.
British magazines, and therefore presumably the buying public, don't like the objective, they like the subjective. Hi-fi, cars and tyres are all reviewed subjectively, even though objective measures exist.
Obviously, subjective opinions are important, but I too would like to see more subjective testing of cars. The decibel level at 70mph and the frequencies that comprise that noise used to be in all Autocar tests - I'd like to see them in all magazine tests. Grip, roll centre, centre of gravity and presumably there are some ride comfort measures too - they would all greatly enhance (not replace - just enhance) existing tests.
Obviously, subjective opinions are important, but I too would like to see more subjective testing of cars. The decibel level at 70mph and the frequencies that comprise that noise used to be in all Autocar tests - I'd like to see them in all magazine tests. Grip, roll centre, centre of gravity and presumably there are some ride comfort measures too - they would all greatly enhance (not replace - just enhance) existing tests.
Cactussed said:
Really?
I've never visited a tyre factory however I'd be surprised if tyres weren't batch mixed by computer controlled measuring and machine moulded in computer controlled production lines.
They're not hand-carved by elves...
I think you'd be surprised. I've never visited a tyre factory however I'd be surprised if tyres weren't batch mixed by computer controlled measuring and machine moulded in computer controlled production lines.
They're not hand-carved by elves...
http://www.youtube.com/watch?v=t2me-dkKRLI - shows a MotoGP tyre being made. By hand.
I distinctly remember when Michelin came to F1 they showed guys making F1 tyres. The French factory worked said he could be making a 14" Michelin Energy one day, and the next a F1 tyre, the following day maybe a Pilot Sport, just depending on which line he was working on. I can't find the video on YouTube. Yet.
MY point was, it's silly going to split-second computerised testing when every tyre is different. I might buy a Bridgestone ER300 today, and another 3 months later, and they'll be different. I could buy two ER300 from different batches, and again they'll be different.
For the purposes of a mag test, human controlled testing is sufficient, as no two tyres are identical anyway.
For the purposes of a mag test, human controlled testing is sufficient, as no two tyres are identical anyway.
I think we can agree that different tyres behave differently on different cars. We can also agree that, to a point, they 'feel' differnt to drive. Unfortunately, you can't test all tyres on all cars, and feel is such a subjective thing, its not really a definitive argument on its own.
My point is simply that, when cars get reviewed, they have measurable statistics that are performed in a controlled environment (the same as a basic school science experiment) for comparison purposes. I don't see why tyres aren't subject to the same strigency of testing standards.
I'm not arguing that what I've suggested would be the be-all and end-all, however it'd tell you pretty quickly which tyres have more grip (wet and dry) and which let go more or less progressively (wet and dry) and which really perform better under braking (wet and dry). No subjective arguments, just facts.
My point is simply that, when cars get reviewed, they have measurable statistics that are performed in a controlled environment (the same as a basic school science experiment) for comparison purposes. I don't see why tyres aren't subject to the same strigency of testing standards.
I'm not arguing that what I've suggested would be the be-all and end-all, however it'd tell you pretty quickly which tyres have more grip (wet and dry) and which let go more or less progressively (wet and dry) and which really perform better under braking (wet and dry). No subjective arguments, just facts.
vrooom said:
Tyres react differently on different car. i.e tyres dont work same way on different car. like how they handles at the limit.
This is a good point. Makes magazine tyre tests often irrelevant if you don't have that car or use that particular size.Still interesting reading sometimes.
doogz said:
They do also carry out a series of tests, acceleration, braking, lateral grip etc
My point is that these tests are all done by someone driving a car.I'd actually like to see it done on a computer controlled test vehicle. My main thrust is removal of the human element to the testing, then publication of the underlying data. eg - Get a test vehicle to drive in a prescribed arc. Measure and publish the lateral G's generated. Removes any argument about which tyre has the most grip.
You can set the test vehicle to (say) 3 different weights. Small car, family saloon, 4x4. Gives some additional guidance for various cars. I want to see the underlying data, not a score out of 5. What lateral G's did x tyre manage versus y. Wet and dry.
Perhaps I'm being too pedantic?
Cactussed said:
Perhaps I'm being too pedantic?
While I agree it would be interesting, why not follow your logic all the way through and test cars exactly the same way? We could run one standard set of tests and decide once and for all if a 911 turbo is better than a 458, and in fact find out what the best car in the world is for any given budget.
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