Tire chains for CX-5 GT AWD

Hello folks,

I am about to buy tire chains for my AWD CX-5, the user's manual says that you should only put the chains in the front tires. I have been reading some threads were people are saying that the four tires should have them for AWD models. I don't understand why they suggest something not recommended by Mazda. Please explain.

I need the chains for legal purposes to cross mountain passes, but I might use them once a year when I for some reason find myself driving around places with some patches of black ice for extra traction.

Thanks!

I'm not sure you need them in WA.

Read Post #19 here: http://www.mazdas247.com/forum/showthread.php?123844979-Need-advice-planning-to-buy-a-new-CX-5/page2

I thought only 2WD cars were required to have chains and that AWD/4WD is okay? I don't live in the Pac NW anymore, though.

bxpretzel said:

I thought only 2WD cars were required to have chains and that AWD/4WD is okay? I don't live in the Pac NW anymore, though.

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Here's the thing, you can't manually activate AWD on the CX5 and most others in the class. AWD only activates ONCE slipping is detected. If you are descending a hill using engine braking, the rear wheels are freewheeling. (There may be a technique to keep the Mazda AWD system from unlocking if you're coasting but I haven't seen mention of it.) You only have the traction available to the front wheels. With a lockable AWD/4WD the rear wheels are locked and synced to the front giving extra drag and traction. It's been a while since I lived out west with chain up passes but I would expect that basic on demand AWD systems wouldn't pass the requirement.

For the OP, not every AWD system is the same. Some are systems are continously engaged to various degrees, others only connect when needed. I would see no reason other than clearance why you couldn't put 4 chains/cables on as it'll only traction. Certainly if you only are going to install on one axle, the front is where they should go. Installing only on the back would do no good.

You should only use chains (or, more likely, cables) on the front wheels on your AWD CX-5, like the manual says.
The reason is that the front wheels get power 100% of the time and the rear wheels get it only some of the time.

Chains provide superior traction, better then what most tires can provide you with. The downside is that they are very crude devices, which limit driving speed, introduce harsh vibrations and noise, especially if there is little snow and, if not installed properly, can seriously damage your car.
If you have 4WD or AWD you'd still get superior traction with chains. If you have snow tires, you are probably better off because of the above limitations of chains, despite that you might get less traction.

If all wheels were locked together, which is not the case in the CX-5, putting chains on 2 out of the 4 could introduce uneven wheel circumference leading to stress / damage in the drive system. That is why some people say you should put chains on all 4 wheels.
I don't think putting chains on all 4 wheels will do any damage to the car (other than the limitations I mentioned above), but is simply not necessary. Best follow the user-manual recommendation.

rjdee said:

Here's the thing, you can't manually activate AWD on the CX5 and most others in the class. AWD only activates ONCE slipping is detected. If you are descending a hill using engine braking, the rear wheels are freewheeling. (There may be a technique to keep the Mazda AWD system from unlocking if you're coasting but I haven't seen mention of it.) You only have the traction available to the front wheels. With a lockable AWD/4WD the rear wheels are locked and synced to the front giving extra drag and traction.

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Oh boy, where to begin...

I get so tired of people who believe an old school 4x4 is better in winter icy conditions than an on-demand electronically controlled AWD system like the CX-5.

I've been driving 4x4's all my life and still have one today (2010 F-150). 4x4's cannot be engaged in mixed conditions without doing expensive transmission/driveline damage and accelerated tire wear, especially at speeds above 20-35 mph (but also at any speed including a crawl). This means if the road is 50% patches of bare/wet pavement and 50% wet glaze ice, you are in 2WD. An AWD will apply power to wheels as needed.

The transfer case of a 4x4 does transfer power to an additional two wheels but it functions like an open differential in that it applies the power to the wheels with the least amount of traction, just what you don't need when some wheels are already spinning. A 4x4 has no way to tell which wheels are spinning while the AWD of the CX-5 is smart and can apply power to the wheels that are not spinning. The worst thing you can have under icy conditions is 4x4 with full lockers. This will cause excessive loss of traction on icy corners.

Finally, a good anti-lock braking system combined with stability control is much preferable to 4x4 for descending icy hills. This is because ABS works on each wheel as needed, something that is not possible for even the most skilled driver to achieve. Only in deeper snow (where the snow packs in front of a locked wheel) can manual braking (locked up) out perform anti-lock braking.

It's been a while since I lived out west with chain up passes but I would expect that basic on demand AWD systems wouldn't pass the requirement.

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AWD meets the same legal requirements as 4x4. The laws are screwy though because I've driven in plenty of treacherous conditions where, AWD or 4WD, either way, chains or snow tires were still necessary. If the laws were rational they would require snow tires (or chains) for winter storm conditions, not AWD or 4x4.

For the OP, not every AWD system is the same. Some are systems are continously engaged to various degrees, others only connect when needed.

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True, and for treacherous roads, the kind of drive system that only connects when needed is much preferable. But, in the end, it's really all about your tires (and of course your driver skill).

Hopefully never have to use them with good snow tires but I picked these up for the CX last fall.

http://www.tirechainsupply.com/product108.html

I have seen a few times over the years in ice storms when they were legally required even on AWD & 4WDs on a few of the passes.

MikeM. said:

Oh boy, where to begin...

I get so tired of people who believe an old school 4x4 is better in winter icy conditions than an on-demand electronically controlled AWD system like the CX-5.

I've been driving 4x4's all my life and still have one today (2010 F-150). 4x4's cannot be engaged in mixed conditions without doing expensive transmission/driveline damage and accelerated tire wear, especially at speeds above 20-35 mph (but also at any speed including a crawl). This means if the road is 50% patches of bare/wet pavement and 50% wet glaze ice, you are in 2WD. An AWD will apply power to wheels as needed.

The transfer case of a 4x4 does transfer power to an additional two wheels but it functions like an open differential in that it applies the power to the wheels with the least amount of traction, just what you don't need when some wheels are already spinning. A 4x4 has no way to tell which wheels are spinning while the AWD of the CX-5 is smart and can apply power to the wheels that are not spinning. The worst thing you can have under icy conditions is 4x4 with full lockers. This will cause excessive loss of traction on icy corners.

Finally, a good anti-lock braking system combined with stability control is much preferable to 4x4 for descending icy hills. This is because ABS works on each wheel as needed, something that is not possible for even the most skilled driver to achieve. Only in deeper snow (where the snow packs in front of a locked wheel) can manual braking (locked up) out perform anti-lock braking.



AWD meets the same legal requirements as 4x4. The laws are screwy though because I've driven in plenty of treacherous conditions where, AWD or 4WD, either way, chains or snow tires were still necessary. If the laws were rational they would require snow tires (or chains) for winter storm conditions, not AWD or 4x4.



True, and for treacherous roads, the kind of drive system that only connects when needed is much preferable. But, in the end, it's really all about your tires (and of course your driver skill).

Click to expand...

Totally agree with you, and if I might add, I've driven a mix of true 4x4 and more recently modern AWD systems and unless you are extreme off-roading or mud bogging every days (doubtful for probably most CX-fivers) I think the modern AWD systems work better than the relatively crude 4x4 systems of the past. At least that's my experience so far.

Here is the WA state WAC on tire chains.

http://apps.leg.wa.gov/WAC/default.aspx?cite=204-24-050