I can concur with new or higher traction tires, going in the rear for the vast majority of cases (99.99%).
As stated, it's about the vehicle's handling and reactions under the differing setups.
But here's one of the valid questions AJ posed that no one answered because tey might not know the answer.
How is braking in a straight line affected by grippier tires in the front vs grippier tires in the rear? Most folks don't know this but it actually depends on the vehicle's weight distribution. The more front heavy the vehicle is, the more important it is to have the good tires on the rear.
Yes, weight transfer throws more weight to the front, but you must try to understand the dynamics of tire traction and how it is affected by load to fully grasp the outcome.
Tire traction increases with the load on the tire, but the increase is not linear. In other words if you have 2 tires with equal 50% load on them, they will have greater traction than transferring 100% of the load to one tire. Now that may seem intuitive and simple since the one tire has less surface area than 2, but here's another example;
4 tires with each tire experiencing 25% of the total load (would only happen under braking if the car's weight was pretty rear-biased) will have more traction than a car where the front tires each has 40% of the total load and the rear tires each only experience 10%.
By putting the igher traction tires in the front, yes, they have more load to work with, but they will also cause increased weight transfer to the front axle reducing the rear tires' grip even further. This also makes the vehicle much more unstable under braking.
When a vehicle's static weight distribution is heavily front-biased, this has the greatest negative effect when the grippier tires are placed in front. In fact, if the vehicle has a closer to 50:50 weight distribution (or even a rear-heavy distribution), it can handle grippier tires in front better than a front-heavy vehicle. Of course, the vehicle's CG also makes a difference in dynamic weight transfer. Now if the vehicle is heavily front-biased (over ~61%, a Neon being ~65% front) it's possible to actually get worse straight line braking distances with the snow tires in front vs in the rear only, and stability under emergency braking will undoubtedly be bad.
Someone interested enough to not mind the effort involved can actually test this for themselves (and for their own vehicle) the next time they find a snow covered empty lot. Try braking in a straight line from a set speed (say ~35mph) with snow tires in front only and with snow tires in the rear only. If the vehicle is very front heavy, you could see braking distances as much as 1/3rd longer with the snow tires in front.
The reduction in rear traction vs. front also makes the car much more unstable under cornering. While an excessively understeering car is also slow, it will be easier to complete a slalom in an excessively understeering car than an excessively oversteering one. The transitions in the slaloms and the resultant weight transfer will make the rear swing wider and wider making the car difficult to control.
As folks have already mentioned, most people can contend with understeer, while it takes practice to deal with oversteer, especially snap oversteer when it's not expected or intentionally provoked, which is why it's recommended that the grippier tires go in the rear.
A few winters ago, a friend of mine had 2 winter tires put on her FWD car, thinking (as many folks seem to), that the vehicle is fwd, the snow tires should go in front for the winter. The shop that put them on for her never mentioned the dangers of doing that and while she was driving on a curve on the interstate, a vehicle in front started swerving from hitting a patch of ice-covered snow, she hit her brakes and the rear of her car immediately came around, she slid sideways off her lane and was T-boned by an SUV.
She was extremely fortunate to escape serious injury. The insurance company paid for her totalled vehicle and when I found out about the whole incident, I was mad that the folks at the shop never advised her about the dangers.
As someone stated, in some parts of Canada, it's illegal to mount studded tires only in the front because it unbalances the vehicles handling and stability that badly. Even in the US, there are some states where insurance companies do not have to pay out for accidents in the winter if it's discovered that the vehicle that lost control had winter tires mounted only on the front axle.
Max
As stated, it's about the vehicle's handling and reactions under the differing setups.
But here's one of the valid questions AJ posed that no one answered because tey might not know the answer.
How is braking in a straight line affected by grippier tires in the front vs grippier tires in the rear? Most folks don't know this but it actually depends on the vehicle's weight distribution. The more front heavy the vehicle is, the more important it is to have the good tires on the rear.
Yes, weight transfer throws more weight to the front, but you must try to understand the dynamics of tire traction and how it is affected by load to fully grasp the outcome.
Tire traction increases with the load on the tire, but the increase is not linear. In other words if you have 2 tires with equal 50% load on them, they will have greater traction than transferring 100% of the load to one tire. Now that may seem intuitive and simple since the one tire has less surface area than 2, but here's another example;
4 tires with each tire experiencing 25% of the total load (would only happen under braking if the car's weight was pretty rear-biased) will have more traction than a car where the front tires each has 40% of the total load and the rear tires each only experience 10%.
By putting the igher traction tires in the front, yes, they have more load to work with, but they will also cause increased weight transfer to the front axle reducing the rear tires' grip even further. This also makes the vehicle much more unstable under braking.
When a vehicle's static weight distribution is heavily front-biased, this has the greatest negative effect when the grippier tires are placed in front. In fact, if the vehicle has a closer to 50:50 weight distribution (or even a rear-heavy distribution), it can handle grippier tires in front better than a front-heavy vehicle. Of course, the vehicle's CG also makes a difference in dynamic weight transfer. Now if the vehicle is heavily front-biased (over ~61%, a Neon being ~65% front) it's possible to actually get worse straight line braking distances with the snow tires in front vs in the rear only, and stability under emergency braking will undoubtedly be bad.
Someone interested enough to not mind the effort involved can actually test this for themselves (and for their own vehicle) the next time they find a snow covered empty lot. Try braking in a straight line from a set speed (say ~35mph) with snow tires in front only and with snow tires in the rear only. If the vehicle is very front heavy, you could see braking distances as much as 1/3rd longer with the snow tires in front.
The reduction in rear traction vs. front also makes the car much more unstable under cornering. While an excessively understeering car is also slow, it will be easier to complete a slalom in an excessively understeering car than an excessively oversteering one. The transitions in the slaloms and the resultant weight transfer will make the rear swing wider and wider making the car difficult to control.
As folks have already mentioned, most people can contend with understeer, while it takes practice to deal with oversteer, especially snap oversteer when it's not expected or intentionally provoked, which is why it's recommended that the grippier tires go in the rear.
A few winters ago, a friend of mine had 2 winter tires put on her FWD car, thinking (as many folks seem to), that the vehicle is fwd, the snow tires should go in front for the winter. The shop that put them on for her never mentioned the dangers of doing that and while she was driving on a curve on the interstate, a vehicle in front started swerving from hitting a patch of ice-covered snow, she hit her brakes and the rear of her car immediately came around, she slid sideways off her lane and was T-boned by an SUV.
She was extremely fortunate to escape serious injury. The insurance company paid for her totalled vehicle and when I found out about the whole incident, I was mad that the folks at the shop never advised her about the dangers.
As someone stated, in some parts of Canada, it's illegal to mount studded tires only in the front because it unbalances the vehicles handling and stability that badly. Even in the US, there are some states where insurance companies do not have to pay out for accidents in the winter if it's discovered that the vehicle that lost control had winter tires mounted only on the front axle.
Max
