'04 XC70 -- Snow Tires, Uneven Tread Wear

[BlackBart]

In my experience the best tire on a fwd should be in front. They need to plow through any water, they need to brake, they need to steer, they need to steer while braking. You don't want shallow tread up there.

[Rattnalle]

In my experience the best tire on a fwd should be in front. They need to plow through any water, they need to brake, they need to steer, they need to steer while braking. You don't want shallow tread up there.

It's better for getting forward but less safe. Average Joe isn't a very good driver so we, that is Vision Zero Land, want the recommendations in favour of safety first and foremost to save the rest of us (and Joe).

[MoVolvos]

In my experience the best tire on a fwd should be in front.

Having worked at Pepboys in the mid 90's I was quite surprise years later while buying new tires at Costco that policy changed thanks to Michelin. They also change their policy on tread depth. Can't remember as my tires are well rotated enough but if it differs by a certain depth you must change all 4 tires.

It's still safer to have them up front for everyday driving as Michelin's test was to the limit in a given condition but what is one driver's opinion vs Goliath Michelin? At those test speed and for those that drive way too fast to the limit will drive till they spin regardless.
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"When tires are replaced in pairs...the new tires should always be installed on the rear axle and the partially worn tires moved to the front."
https://www.tirerack.com/tires/tiretech ... ?techid=52

[Rattnalle]

It's not safer up front. It's better for traction. You're confusing the two. Safety includes what happens when you actually do have an accident. Sliding sideways into something is considerably more deadly than head on. But it's your own lives. Just don't criticise the recommendations because you don't understand why they're given. Or tell others they're not good for the same reason.

[abscate]

When they hit 3/32 of tread they are dead.

If you have uneven wear on one side, don’t debate if they should go on the back or front, just take the money you “ saved” not replacing your lower control arms, ball joints, and tie rod ends.......and spend it on new tires.

Bad tire tread fines should be about $600 per incident to make an obvious point

[MoVolvos]

It's not safer up front. It's better for traction. You're confusing the two. Safety includes what happens when you actually do have an accident. Sliding sideways into something is considerably more deadly than head on. But it's your own lives. Just don't criticise the recommendations because you don't understand why they're given. Or tell others they're not good for the same reason.

I read the article and saw the Michelin test on the Taurus when it first came out and fully understand what they are saying. That being said I've only spun out one time and that was unintentional because the mountainous road I was on had a hair pin unexpectedly. I had only driven that road a few times due to a new job and there was a light drizzle that morning. Front wheel drive 2 door Prelude with good tires all the way around.

If you can pull up a video of their test it is designed so that it would be obviously be unsafe at those speeds and tire combination. Every car has it's limits of adhesion and this with good tires. Due to that test Michelin probably created the front to rear tread differential to cover themselves so the two tires wouldn't have such a large tread depth difference. They are doing that to cover themselves because they know that differential would guarantee the rears to come out in their test. If they knowingly discovered a problem they would have to create a solution or else they would be liable for not reporting a dangerous find in the high to low tread combination.

How can it be that for so many years all manufacturers went with the good front tires concept. I'm old enough to remember way back when everything was rear wheels and all of sudden with front wheel drive best tires were up front. Just look at their test criteria. They got themselves into trouble and had to create a recommendation due to it.

If I were to create a law on tread depth I would say everyone needs to rotate tires and all tires need to be replace at one time. Every country has their ideas of safety and what it considered a road worthy car. It's like gas or insurance. Whether we like it or not it's part of the cost of ownership.

I digress here but don't drive with such a large difference in tire depth front to back and this would be a none issue besides a safety issue at the limits of that combination.

[abscate]

Just to shock the Swedish on this Forum..on the map below, the States without either solid blue or blue stripes...

...........Do not inspect cars at all.

[E Showell]

Guys, this is for an AWD wagon. I have spun a car exactly once and only through 90 deg. (1968 VW Squareback on black ice going downhill accelerating away from a stoplight at about 10 mph).

[Rattnalle]

It's not safer up front. It's better for traction. You're confusing the two. Safety includes what happens when you actually do have an accident. Sliding sideways into something is considerably more deadly than head on. But it's your own lives. Just don't criticise the recommendations because you don't understand why they're given. Or tell others they're not good for the same reason.

I read the article and saw the Michelin test on the Taurus when it first came out and fully understand what they are saying. That being said I've only spun out one time and that was unintentional because the mountainous road I was on had a hair pin unexpectedly. I had only driven that road a few times due to a new job and there was a light drizzle that morning. Front wheel drive 2 door Prelude with good tires all the way around.

If you can pull up a video of their test it is designed so that it would be obviously be unsafe at those speeds and tire combination. Every car has it's limits of adhesion and this with good tires. Due to that test Michelin probably created the front to rear tread differential to cover themselves so the two tires wouldn't have such a large tread depth difference. They are doing that to cover themselves because they know that differential would guarantee the rears to come out in their test. If they knowingly discovered a problem they would have to create a solution or else they would be liable for not reporting a dangerous find in the high to low tread combination.

How can it be that for so many years all manufacturers went with the good front tires concept. I'm old enough to remember way back when everything was rear wheels and all of sudden with front wheel drive best tires were up front. Just look at their test criteria. They got themselves into trouble and had to create a recommendation due to it.

If I were to create a law on tread depth I would say everyone needs to rotate tires and all tires need to be replace at one time. Every country has their ideas of safety and what it considered a road worthy car. It's like gas or insurance. Whether we like it or not it's part of the cost of ownership.

I digress here but don't drive with such a large difference in tire depth front to back and this would be a none issue besides a safety issue at the limits of that combination.

Fair enough, I might've read too much into your statement.

I've never heard that Michelin is the source for this recommendation to begin with. Over here it's the official recommendation from the government and from road safety organisations.

The reasoning is mostly logic but I can check if I can find some data to back it up. The idea is it's safer on a population level because the average driver is a rather poor driver. Accidents following understeer are less lethal than accidents following oversteer. This is because cars are safer in head on impacts than side or rear impacts. For experienced drivers who know what they're doing and know how their car reacts when it lets go different driving dynamics can be perfectly ok. For most other people handling oversteer is much harder. Personally I prefer understeer as well even though I'm otherwise perfectly comfortable to have the car slipping and sliding around the road when it's snowy or icy.

The old idea to use the best tyres on the driving axle was relevant when tyres were poorer and you needed the traction to get anywhere, especially in snow. But this was before road safety was even a subject anyone thought about. With modern tyres and cars with torque vectoring and anti-spin it's not much or an issue anymorr.

The total tyre economy will be the same regardless if tyres are replaced in pairs or all four. And yes of course too worn tyres are unsafe but they are regardless or if you're running two or four too worn tyres. I rotate mine so they're all about the same since it's simpler to shop for four at a time.

[Rattnalle]

Just to shock the Swedish on this Forum..on the map below, the States without either solid blue or blue stripes...

...........Do not inspect cars at all.

Yikes.

Considering the rust buckets people get away with driving here even with inspections that's not a scenario I'd feel comfortable about.