FWD - Death traps with miss matched tires.

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Originally Posted by exranger06
This is exactly why Tire Rack recommends installing the 2 snow tires on the rear, even on front wheel drive cars. The same applies to all-season tires; for example if you're replacing only 2 tires and you'll have 2 brand new all-season tires and 2 half-worn all-seasons. The new all-seasons should go on the rear.
https://www.tirerack.com/tires/tiretech/techpage.jsp?techid=52



That's a stretch of an assumption you're making of TireRack. In fact TireRack recommends putting snow tires on all four corners
Winter / Snow Tire Tech: Four Winter Tires...The Only Way To Go
 
Originally Posted by exranger06
This is exactly why Tire Rack recommends installing the 2 snow tires on the rear, even on front wheel drive cars. The same applies to all-season tires; for example if you're replacing only 2 tires and you'll have 2 brand new all-season tires and 2 half-worn all-seasons. The new all-seasons should go on the rear.
https://www.tirerack.com/tires/tiretech/techpage.jsp?techid=52

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Intuition suggests that since the front tires wore out first and because there is still about half of the tread remaining on the rear tires, the new tires should be installed on the front axle.....
However, in this case, intuition isn't right...and following it can be downright dangerous. When tires are replaced in pairs in situations like these, the new tires should always be installed on the rear axle and the partially worn tires moved to the front. New tires on the rear axle help the driver more easily maintain control on wet roads since deeper treaded tires are better at resisting hydroplaning.....
...If the front tires have significantly less tread depth than the rear tires, the front tires will begin to hydroplane and lose traction on wet roads before the rear tires. While this will cause the vehicle to understeer (the vehicle wants to continue driving straight ahead), understeer is relatively easy to control because releasing the gas pedal will slow the vehicle and help the driver maintain control.

However, if the front tires have significantly more tread depth than the rear tires, the rear tires will begin to hydroplane and lose traction on wet roads before the fronts. This will cause the vehicle to oversteer (the vehicle will want to spin). Oversteer is far more difficult to control and in addition to the initial distress felt when the rear of the car starts sliding, quickly releasing the gas pedal in an attempt to slow down may actually make it more difficult for the driver to regain control, possibly causing a complete spinout.

WHere I am coming from, half of population would not be able to come back home if they had snow tires on rear axle. 20 years ago, although snow tires are mandatory most people could not afford all 4 snow tires. Put snow tires on rear axle and you are not coming back to dinner.
 
Originally Posted by Fordiesel69
**This thread will only apply to people that drive in snow and ice***

Some people believe in being cheap and only putting snow tires on the drive axle as that is what was done in the old days when they were growing up. All they had primarily was RWD rear wheel drive beasts which no doubt was not an issue, you just had to plan your stops better and pump the brakes. And quite frankly the traction was limited anyways with tires of that era. Cars simple weighed a lot and people adapted and im sure lots of people crashed too.

Fast forwarding directly to the point, I can reproduce it every time and cannot recover it very well. If you place 2 nice studded snow tires on the front axle of a FWD vehicle, and leave your all season tires on the rear, the back end will get loose on you when you let OFF the gas pedal. When you try to correct the issue or hit the brakes, it will make it worse. The only way to recover is to step hard on the gas and steer away to the direction you want it to recover. BUT.....if you are trying to slow down or stop for an intersection, this wont work either.

So.....we know the answer is to buy 4 snow tires and the problem goes away, but my question is simple, with good skill is there a technique to recover this oversteer condition and still get the vehicle stopped? Or will a modern vehicle with ABS or stability control prevent this?




The four matching tires rule is ideal but people are cheap and want to cut corners or think the tire shop or employee is selling more that what's is needed not really believing the way a car behaves with just two of the four correct tires. FWD does a good job pulling out of trouble as you say and ABS is a good substitute for pumping brakes they way we used to do it. I tend to drop the auto into sport mode at times as it gears lower and both engine speed and tires cause drag to kill momentum. This does not inhibit steering the way a stab at brakes would on ice.
ABS helps maintain steering input but it is at cost IMO. In the worst case situations like glare ice, off-camber downward hill, the vehicle is still going to glide toward the fall line once the tires are skating. I say practice these maneuvers where possible to gain some feel for the tries you have, the ice or snow you get in that area and try to get comfortable at that threshold in a controlled area. The pucker factor that visits us only detracts in our ability to smoothly control a situation. Being all rigid or in a state of panic is an added obstacle we don't need.

Originally Posted by Dave9
The answer is simple. Don't think in terms of "these FWD winter tires allow me to drive faster", rather think "these FWD winter tires allow me to not get stuck as easily". If you're going the same slow speed that you'd need to stay stable with all season tires on both axles, you have that on the rear wheels still no matter what you have on the FWD wheels.

If the conditions are really hairy, particularly needing to go DOWN steep/icy hills, you need all 4 tires to be winter tires and even then, re-evaluate your true need to drive those roads. Even if it isn't you that loses control, it can easily be someone else that does then hits you.

Can you recover from rear end loss? Sure, but you better have some space around you, and practice, and ability to stay calm in such situations which is where many people go wrong, panicking instead of driving their way out of it, but to be fair, in a variable traction environment, you won't know how much compensation is overcompensation till you get some traction and start changing course.

If you think it's not safe to drive or are too impatient to drive slow enough for the conditions (or arguably the other vehicles on the road are doing this), don't drive unless the need outweighs the risk.


100 % ALL the above.
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If you don't want panic, getting stuck, hit, crashing or sliding, drive the speed and roads that won't invite trouble if you get out at all. Waiting a bit often helps too; Plows or road crews out working on it or a warm sunny temp rise can mean big advantages. Your patience might keep you off the road at the worst times and others on the road that are impatient might be drivers that will end up hitting someone else that was probably doing everything right.
 
Originally Posted by UG_Passat
Originally Posted by exranger06
This is exactly why Tire Rack recommends installing the 2 snow tires on the rear, even on front wheel drive cars. The same applies to all-season tires; for example if you're replacing only 2 tires and you'll have 2 brand new all-season tires and 2 half-worn all-seasons. The new all-seasons should go on the rear.
https://www.tirerack.com/tires/tiretech/techpage.jsp?techid=52



That's a stretch of an assumption you're making of TireRack. In fact TireRack recommends putting snow tires on all four corners
Winter / Snow Tire Tech: Four Winter Tires...The Only Way To Go


Obviously 4 snow tires is best, and it's easy to see why Tire Rack recommends it. However, I know I've read an article from them where they recommended 4 snow tires, but IF you're installing only 2, to put them on the back, even on a FWD car. I can't find that article now. Maybe they've eliminated that part to encourage more people to just run 4 snow tires. Regardless, in the article I linked, they DO recommend putting the best tires that will have the most traction on the rear (again, even on FWD vehicles), and they explain why. They don't specifically mention snow tires in that article, but obviously the pair of snow tires will have better traction than the pair of all season tires in the snow, so they should go on the back.
 
Originally Posted by exranger06


Obviously 4 snow tires is best ... but IF you're installing only 2, to put them on the back, even on a FWD car.



Great idea on a FWD car.

So now you can't get moving, and if you do get moving, you can't stop or turn.

But at least you won't spin. Yeaaaah.
 
I used to run studded snow tires on FWD front only. I did this for years before i could afford a 4wd vehicle. I used these tires on the early grand-ams, and cutlass cieras, and an olds calais.

I had no problems At all as long as you did not hit the brakes hard when turning. If you were easy and anticipated stops, i had no problem stopping much shorter that i could with regular tires. And on sleet and freezing rain they worked great. With the studded tires on front you can turn and accelerate. You slow down and slightly accelerated as you turn.

I'm sure all four studded would work better. I was on call for years and used to keep 2 studded tires in the trunk that i could swap on and off as needed.

In fairness now that i have 4wd i have not tried stud-less winter tires on ice or snow, so i can't compare. I will say that my fwd car with front only studs would stop better than my truck ever will.

The only real problem i had was people following too close on ice. They did not realize the car in front of them had more ability to stop on ice and snow. I came close to being rear ended several times.
 
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I did this for years and now we have a 4WD Jeep Cherokee with M+S tires on it. I never had an issue with snows on the front only but I always kept decent tires on the back. Never used studs on a FWD car either as around here snows are all you really need. FWIW we didn't get any major snow this year and I'm happy for that. I just looked at the extended forecast and it looks like we skated by this year w/o snow.
 
So we all know static and dynamic friction, that is, once you start sliding it's easier to keep sliding.

All-seasons have a measurable spread between the two.

Winter tires narrowed it, and recover better with "good driving techniques" that we all thing we possess in above-average abilities.

All-seasons also seem tuned for only straight-ahead accelleration and stopping. Get them sideways and all heck breaks loose.

Winter tires were born to hold on in those gentle slides that can lead to spin-outs. So they need to be in the rear.

Fronts, meh, if you want to understeer while gunning it in FWD, that will work itself out as soon as you let off the gas. But might as well get some good rubber up there too, it's where the engine weight lives.

My brake bias would like to lock the fronts up first, which is fine. I have independent control over the rear axle.
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If you have worse tires in the rear, you may get by in ruts because your front tires are plowing the way. Get some curve in, though, and the rears aren't in those tracks anymore. Good luck to ya!
 
I have ‘mismatched' tires on my truck right now. I hit some metal on the road, took out an OEM Goodyear at 25k. I have two almost new Michelins on the rear, 2 older Wranglers on the front. OBTW, no accidents with 40 years as a licensed driver, must be lucky.
 
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