Monday, November 23, 2009
Mahler: Winter tires lesson lost already?
NOTE: This article originally appeared on line on Wednesday, November 18, 2009. (Click here to read original article on this website). However, late Tuesday, November 17, following our meeting with the Minister of Education Roland Hache on Monday, November 16, Valerie Kilfoil, Communications Director for the New Brunswick Department of Education announced that the Department would follow Transport Canada's lead in the winter tire issue. The New Brunswick media followed up by interviewing Mr. David Hoar, a Fredericton based engineering consultant who has been hired by the Department of Education to advise on winter tires. Mr. Hoar insisted that he was right and everyone else was wrong. So Wheel's Magazine journalist John Mahler revised the on line article to include a new interview with Mr. Hoar.
The result was the same. Internationally recognized automotive tire expert John Mahler and all the industry experts he interviewed still say Mr. Hoar and the NB Department of Education are wrong.
REVISED ARTICLE WITH INTERVIEW WITH DAVID HOAR
Mothers of New Brunswick teens killed in school van crash shocked to find inquest directives not followed
Nov 21, 2009
by John Mahler, Wheels Magazine
Click here to read the story in Wheels Magazine
Have you ever looked at the tires on your child's school minibus?
I haven't either.
Three New Brunswick women have and they didn't like what they saw, and they are very, very angry.
And so am I.
Isabelle Hains, Marcella Kelly and Ana Acevedo all lost sons in the tragic crash of a 15-passenger school van in which seven members of the Bathurst High School basketball team and one teacher died. The school van collided with a transport truck in January 2008.
The pair lobbied for an inquest, so the results would help ensure this kind of tragedy would never recur. Eventually they succeeded.
One of the many recommendations coming out of the inquest was that all school buses be equipped with winter tires during the winter. The mothers thought they had won an important victory for children's safety.
So imagine their shock last month when they saw that the minibus used to transport students to extracurricular activities at Bathurst High School was not fully equipped with winter tires. School District 15 had equipped the bus with Hakkapeliitta winter tires on the dual rear wheels and Michelin LTX all-season (light truck) tires on the front wheels.
"It would appear they haven't learned their lesson," was Hains' reaction.
Hains did some research and found out that, to be effective, winter tires are required on all wheels. She checked with experts including Nigel Mortimer of Transport Canada and the Star's Tire Guy – me. We both advised her that, yes, winter tires are required on all wheels for maximum safety.
An easy fix. Notify the board and they'll change the tires, you'd think.
Wrong! The superintendent of the board, John McLaughlin, replied that the board had met the directive from the New Brunswick ministry of education that applies to much larger school buses. But that directive left a loophole so big you could drive a minibus through it.
Transport Canada's Mortimer wrote to the board, pointing out the error. I supplied Hains with research material to help her cause. The board politely told Mortimer to mind his own business. Transport Canada has no provincial jurisdiction on the bus tire issue.
I spoke with David Hoar, an independent consultant who is contracted to the New Brunswick government to provide tire expertise.
He agreed that for four-wheel-drive or all-wheel-drive vehicles, "by all means, (they) should be equipped with comfortable traction tires at all four corners, there's no question."
But he does not agree on winter tires on all positions on rear wheel drive vehicles.
"If you do back off the throttle, the vehicle has a tendency to brake from the rear and keep that vehicle straight," he says.
"There is the condition of an innocent driver going below speed limit on a highway, who hits a patch of ice or slush, backing off the throttle keeps the vehicle straight, and if it takes him two or three seconds to recover that vehicle, he has time to regain control.
"If you put snow tires on, you improve your traction, you improve your braking. At low speed, yes, but there are no studies that we can obtain that prove that this is true at highway speeds."
In other words, at higher speeds he feels the lack of front grip is better as it gives the driver more time to solve the problems.
He went on to say that "it sounds good to say, `let's put snow tires all around.' But where we have this identifiable condition on the highway, a loss of lateral control on the highway, we usually end up in one or two things happening: The vehicle will either end up heading for the ditch or will head over into the other lane. Very seldom does it ever stay straight once it loses its lateral control.
"If I am incorrect, prove me wrong with the data. If the tire companies have the data, Transport Canada can force them to give access."
I checked with contacts at the tire companies to make sure we were on the right track.
Michelin North America's Ron Margadonna, senior technical marketing manager, replied: "It is clear that the tire industry recommends winter tires on ALL wheel positions for safe driving in winter conditions.
"However, if a consumer so chooses to only purchase two winter tires (based on a four-wheel- or rear-drive vehicle only), these tires should be installed on the rear axle of the vehicle. This would also apply on a bus.
"In addition, the consumer needs to know that by not installing winter tires on all wheel positions, a traction imbalance results, which can create a vehicle stability issue, especially when cornering or during an emergency manoeuvring or braking scenario."
Toyo Tire's Canadian public relations manager, James de Chavez replied: "The theory is the same for a car as it is for a small bus. Therefore, winter tires need to be on every axle to gain the true benefits received from a winter tire.
"An LT (light truck) metric tire will not achieve what a true winter tire can in snowy conditions, therefore mixing and matching them is not recommended."
Bridgestone North America's Guy Walenga, director of engineering, commercial product technology, also found the board's decision strange.
"There is more than one answer to this question," he replied. He likened the all-season-on-the-front setup to a large tractor-trailer unit that, in the winter, typically uses winter tires for traction on the drive wheels only, but which is a much different vehicle.
"A front rib tire setup may be okay for a pro driver," he said. "On the mini-bus, is this the best setup? No. In braking on snow, when weight transfers forward, winters on the front will stop better than all-seasons. In a corner when grip is lost, understeer is the best of a bad situation."
Walenga offered the example of the worst-case scenario: "The driver is enroute, it starts snowing, the driver has a headache, the kids are screaming in back – two winter tires on front are better than Excedrin. For non-pro drivers, winter tires on the front will give a driver more confidence. Confidence makes for a better driver."
And I contacted Joerg Burfien, Continental Tire's director of R&D for the Americas, who said that Continental has conducted a great deal of "mixed fitment" tire testing.
"With all-seasons in the front and winter tires on the (dual) rear axle – stopping will likely be an issue! You will for sure not be able to stop as fast as you're able to accelerate.
"Two simple reasons for this: traction for all-season tires in snow is much lower and when you brake your weight is shifting forward, so the increased traction in the rear is not helping much. Actually, you can't expect more than 25 per cent stopping power to come from the rear anyway.
"The same is valid for steering or steering response. You will have a very solid rear axle and very limited traction on the front which will promote under-steering conditions. So not really the safest option.
"Continental Tire's position is a strong recommendation to switch to winter tires on all axles as soon as temperatures consistently drop below 7 C."
So it is clear that four winter tires on a bus – or any vehicle for that matter – make a profound difference.
Vehicle braking capability is affected by the imbalance of winter and all-season tires mounted at the same time on the same vehicle.
Tire experts have come to this conclusion, and it's not just because they want to sell more tires. There is serious technology involved in these product decisions and the tires have been created to act in tandem back and front.
It's a no-brainer these days to understand this premise.
The policy is just plain wrong.
John Mahler is Wheels' tire expert.
He can be reached at thetireguy_1 @ hotmail.com, or share your thoughts with readers at firstname.lastname@example.org
Click here to read the story in Wheels Magazine