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Thread ID: 79406	2007-05-19 03:38:00	Snow Tyres	dolby digital (5073)	PC World Chat

Post ID	Timestamp	Content	User
550970	2007-05-19 03:38:00	Did anyone see the item on Closeup last night about the use of snow tyres on imported vehicles . Unfortunately some people have died as a result of going out of control and hitting things . Apparently snow tyres have about 30% less grip on wet roads . It appears in these cases, snow tyres were on the back and the back end let go and the vehicles slid out of control . Now should the importers of the vehicles put tyres better suited to NZ conditions or at least advised purchasers of the use of snow tyres . There is no law in NZ prohibiting the use of snow tyres or in any other country for that matter . Apparently one of the cars had done 360's on at least 2 occasions . Would this not have highlighted a problem . The snow tyres look strange to me and are really flexible . I seem to remember an similar issue with space saver spares and people exceeding 80kph and crashing out of control even though on the tyre it said Do Not Exceed 80kph (mind you, if your knight in shining armour replaced your flat tyre which a space saving spare, would he tell you to not exceed 80kph :o ) The moral is get reasonable tyres unless you never drive in the rain and never drive over 50kph i . e . just drive in town (mind you even then . . . )	dolby digital (5073)
550971	2007-05-19 04:36:00	The moral is be competent or get off the damn road, If the car for whatever reason has poor grip in the wet then drive accordingly, and then fit some tires more suited to the conmditions. The fact that the driver had spun the car out twice already should have rung some bells, no matter how stupid the people concerned. And for the first crash highlighted the report identified 2 flat tires, Doh!, That right there is a bigger issue. Sounds harsher then its meant to be, But people are dead because they didn't wise the hell up.	Metla (12)
550972	2007-05-19 05:39:00	Yes, it was an interesting article, though apparently something similar was on TV3 not long ago, according to this thread ( . pcworld . co . nz/showthread . php?t=78355" target="_blank">pressf1 . pcworld . co . nz) . For those who missed last night's Close Up they have a video of last night's item here ( . co . nz/view/page/497100/1129840" target="_blank">tvnz . co . nz) . It's all very well saying "be competent" but if you're not very savvy when it comes to cars you might not know that your tyres would be dangerous until you actually go for a spin, possibly with lethal consequences . If they don't make it a law to ban snow tyres then it should at least be pointed out when you go for a warrant that changing the tyres is highly recommended for safety .	FoxyMX (5)
550973	2007-05-19 07:34:00	It had more to do with mismatched tyres, under inflated tyres, and people ignoreing the warning signs then with one particular style of tyre. People are making snowtyres out to be at fault, when the entire saga was user error.	Metla (12)
550974	2007-05-19 07:40:00	It's all very well saying "be competent" but if you're not very savvy when it comes to cars you might not know that your tyres would be dangerous until you actually go for a spin, possibly with lethal consequences. .One would presume if your competent to get a licsense, you should also be competent to maintain your car in between WOF inspections. After all it is the duty of every driver that hops in a car that it is up to wof standards	plod (107)
550975	2007-05-19 08:56:00	Did anyone see the item on Closeup last night about the use of snow tyres on imported vehicles . Unfortunately some people have died as a result of going out of control and hitting things . Apparently snow tyres have about 30% less grip on wet roads . It appears in these cases, snow tyres were on the back and the back end let go and the vehicles slid out of control . Now should the importers of the vehicles put tyres better suited to NZ conditions or at least advised purchasers of the use of snow tyres . There is no law in NZ prohibiting the use of snow tyres or in any other country for that matter . Apparently one of the cars had done 360's on at least 2 occasions . Would this not have highlighted a problem . The snow tyres look strange to me and are really flexible . I seem to remember an similar issue with space saver spares and people exceeding 80kph and crashing out of control even though on the tyre it said Do Not Exceed 80kph (mind you, if your knight in shining armour replaced your flat tyre which a space saving spare, would he tell you to not exceed 80kph :o ) The moral is get reasonable tyres unless you never drive in the rain and never drive over 50kph i . e . just drive in town (mind you even then . . . ) I have been selling and servicing tyres or over 15 years . There is a few rules I stick to when selling tyres-- Mud tyres are for mud, highway for highway and all terrain for a bit of both . I was speaking to a rep a few weeks ago about the snow or M+S tyre debate and he raised a valid point, as follows . In Europe and parts of Asia, northern America where they have sub zero temps for months on end people need tyres that perform in these conditions so therefore most manufacturers build Snow tyres . These are designed to be used in temperatures below 3 degrees C in most cases . So when people like us get hold of them with our fresh Jap import car and start running them at 110km/h on a hot summers day(road temp over 50deg/c) and the tyre starts over heating and flys to bits can you really blame the tyre when it is working well beyond its intended purpose? I think not, LTSA should be banning these at the border, simple as that:2cents: Mike	miknz (3731)
550976	2007-05-19 09:03:00	Granted there may be something in it (regards the lack of traction etc) . However, the onus is on the driver to know how well their vehicle handles all kinds of conditions . You drive to the conditions (the first rule of Defensive Driving) . The vehicle you drive is one of those conditions . If the car spun out twice before, surely that would indicate that a) the driver doesn't know their vehicle, and b) there might actually be something wrong with the vehicle . Only an idiot would continue driving in the same manner or not do something to remedy the issue . Alas, its just another on of those times where "it's not my fault, it was <whatever>" . Wise up people, sooner or later you have to cop some of the blame	Myth (110)
550977	2007-05-19 10:43:00	Did anyone see the item on Closeup last night about the use of snow tyres on imported vehicles . Unfortunately some people have died as a result of going out of control and hitting things . Apparently snow tyres have about 30% less grip on wet roads . It appears in these cases, snow tyres were on the back and the back end let go and the vehicles slid out of control . Now should the importers of the vehicles put tyres better suited to NZ conditions or at least advised purchasers of the use of snow tyres . There is no law in NZ prohibiting the use of snow tyres or in any other country for that matter . Apparently one of the cars had done 360's on at least 2 occasions . Would this not have highlighted a problem . The snow tyres look strange to me and are really flexible . I seem to remember an similar issue with space saver spares and people exceeding 80kph and crashing out of control even though on the tyre it said Do Not Exceed 80kph (mind you, if your knight in shining armour replaced your flat tyre which a space saving spare, would he tell you to not exceed 80kph :o ) The moral is get reasonable tyres unless you never drive in the rain and never drive over 50kph i . e . just drive in town (mind you even then . . . ) People will blame whatever they can, rather than their own driving . Not that there isn't some truth to snow tyres offering less grip on NZ normal road conditions . Personally if I was buying a used import, I would negotiate the price down, or demand the car dealer put on proper tyres that are suited to the NZ road conditions .	rogerp (6864)
550978	2007-05-19 10:57:00	pressf1.pcworld.co.nz	tweak'e (69)
550979	2007-05-19 17:30:00	I have been selling and servicing tyres or over 15 years . There is a few rules I stick to when selling tyres-- Mud tyres are for mud, highway for highway and all terrain for a bit of both . I was speaking to a rep a few weeks ago about the snow or M+S tyre debate and he raised a valid point, as follows . In Europe and parts of Asia, northern America where they have sub zero temps for months on end people need tyres that perform in these conditions so therefore most manufacturers build Snow tyres . These are designed to be used in temperatures below 3 degrees C in most cases . So when people like us get hold of them with our fresh Jap import car and start running them at 110km/h on a hot summers day(road temp over 50deg/c) and the tyre starts over heating and flys to bits can you really blame the tyre when it is working well beyond its intended purpose? I think not, LTSA should be banning these at the border, simple as that:2cents: Mike There might be a slight amount of misinformation there about M+S tires in the US . I cannot even think of ANY tires sold here in the US that are not M+S compliant . . . and somehow the point in time when they arrived is lost in my memory . . . . . such as it is . Mud tires are usually very specialized tires for . . . MUD, but are also used for sand by off-road vehicles, usually 4x4's and are not usually operated on freeways at high speed for long periods of time . I don't believe it's a heat problem with them . . . . . just economics . Freeway travel eats the chunky tires pretty fast and a set of Remington "Wide-Brutes" in that pattern at 33x12 . 5R15 cost a lot of money . Besides, they are very noisy . I run Remington "Wide-Brutes" in the RV tread configuration on my Isuzu Amigo (32x11 . 50R15) and my Chevrolet K-5 Blazer (33x12 . 50R15) at all times and they are M+S rated . Tire wear is decent . . . I usually get 40,000 to 50,000 miles (about 72,000 kilometers) on them if I drive them at relatively decent air pressure . Did I say that I like to corner like a madman? I do . . . and that's the highest wear condition I have . I usually run my vehicles at 65-70MPH/105-113KPH, which is a legal speed limit here . Now, since we are actually talking about hysteresis of the rubber in the case of "snow" verses "M+S" or "regular" tires . . which translates in rebound-ability and the resultant amount of heat generated in that flexing . . . we need more information . . . it all comes down to a variety of factors . Wet roads have their own requirements, and for this lecture will be avoided . Typically, a tire depends upon adhesion to the road through a variety of conditions and attitudes and velocities . Adhesion is a property of rubber that causes it to stick to other materials, as you can see with adhesive tape . This "adhesion" is generally thought to be the result of momentary molecular bonding between the two surfaces . The contractile term: "stiction" is recently added to indicate the factor of "sticky-ness" and "friction" values needed or engineered in to tire design(s) . If bond strength is the same at all the bond sites the force that resists sliding is proportional to the total of all the minute areas of contact . Translation: If the two surfaces were perfectly smooth the true area of contact would be the same as the observed area of contact, but this is not the case . Real surfaces are actually very rough on the molecular scale and contact is limited to the highest protuberances on each of the two surfaces . The true area of contact depends on the surface profiles, properties of the materials, and the contact pressure, rolling speed and air-dam effect (aeroplaning) and contaminants on the tire and/or road surface . So . . what's this got to do with snow tires and M+S tires and any other configuration of tires? Generally, "regular use" tires are decently designed to have a "middle ground" in hysteresis (and many other characteristics) as it were . They average person has no real reason to push street sedans to high-G force corners, nor wants to experience tire smoking acceleration . Tires for this type of vehicle are generally rated at moderate treadwear, traction, load and speed qualities . I present a small and incomplete chart for the particular brand of tires for which I am still a dealer: REMINGTON Tire Brand: REMINGTON (Order of information below) Tire Line-Construction-Size-Traction Rating/Temp Rating-Wear Rating TOURING XT120-RADIAL-15 & 16-A/B-560 WIDE BRUTE A/W-RADIAL-ALL-A/B-480 WIDE BRUTE RV-RADIAL-ALL-A/B-500 (my vehicles) ENDEAVOR -RADIAL-14 & 15-A/B-420 EMERALD-RADIAL-14 & 15-A/A-740 (wife's Astrovan) XT120 HR4-RADIAL-ALL-A/A-320 XT120 Z-RADIAL-ALL-A/A-280 As you can see, there's all sorts of designations about tires and traction and wear and heat capacities . Then there's the SPEED RATINGS: . . . these are usually rated at maximum load/weight and 300ºF/149ºC road temperature with normal air pressure . These ratings are manufacturer-voluntary, and are not covered by US DOT standards at this time and are offered only as a point of consideration for now . Q = 99 mph/155 . 32 kph H = 130 mph/209 . 21 kph R = 106 mph/170 . 59 kph V = 149 mph/225 . 3 kph S = 112 mph/180 . 24 kph W = 168 mph*/270 . 36 kph* T = 118 mph/189 . 9 kph Y = 186 mph*/299 . 33 kph* U = 124 mph/199 . 55 kph *For tires with a maximum speed capability over 149 mph/225 . 3 kph, tire manufacturers sometimes use the letters ZR . For those with a maximum speed capability over 186 mph, tire manufacturers always use the letters ZR . What's probably happening is some urban myths are surfacing and although they might have held water in days passed, today's technology isn't even in the same genre . As to using "snow-tires" on the streets in weather that does not require their application, the most a person SHOULD experience is high tire wear and noise, and not so much tire failure unless the tire at hand is poorly constructed and has large areas (blocks) of rubber that are unsupported by the tire carcass, allowing excessive heat to build up, resulting in chunking or de-lamination of the tread shell . Using some poorly constructed "snow" tires at highway speeds CAN cause serious tire failure and loss of control, and these tires should not be used on dry pavement conditions without that thought or consideration in mind . The very high hysteresis of these tires cause heat to build up beyond the capacity of the sidewalls and exposed tread areas to remove it . Most people place entirely too much air in these tires to try to achieve a normal looking profile, again further aggravating the design of the tire in the second place . On the other hand, the snow tire designation was usually associated with tires that could receive studs, and this required some very seriously "hard" rubber compounds to hold the studs in place . These tires are designated "Not for highway use" and if you understand the hysteresis factor involved, you can see why: the generate lots of heat, resist flexing and as such don't deflect to surface irregularities much if at all . Lowered hysteresis (or "sticky-ness, as some people falsely believe) will lower the heat build up . . TO A POINT! Soft, gooey, spongy, sticky tires have a specialty value, not usually demanded or desired on the street or highways . Street racers have moved toward these tires with gusto . . but they wear very fast unless heated to design limits and inflated to certain "mass-moment/energy" values that are ascertained by serious computations including air density, temperature of the road, air and tires, loads to be experienced . . all race track numbers that don't translate well to the variety of conditions met on a drive-race-drive home scenario for a street racer . Even the gas that fills the tires is computed into the equation . . . . nitrogen is currently used in mixture with other "secret" admixes to intensify the design of the tires for very high-dollar racing . . . at factory levels . All this boils down to: "Use the tires as they are designed, for what they are designed, in conditions for which they are designed" . Oh . . . and if the vehicle has front wheel drive, place the "snow tires" on the driving end of the vehicle . . usually the front . . . unless you back up all the time . :groan: If some politician is getting paid off for allowing junk tires to be imported to youse guys from the Orient . . then all bets are off . :mad:	SurferJoe46 (51)
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