FWD or AWD in rain and snow?

[claybakin247]

@NCTelly great in depth explanation! Just read it to hubby over breakfast. Also shared comments and article by @alexdrums and @blitt Thanks to all!

We are located just off I81 between Winchester VA and Hagerstown MD and although our state does a horrible job maintaining and clearing roads, we are not in a rural area nor do we expect to ever be encountering the type of conditions shown in @blitt photo, and most definitely will not be off roading.

Our Telly will spend most of its time in our driveway, as a pleasure car if you will. Long distance vacations and shopping excursions via state and federal roads. It will be “my” car. I am purchasing it with income from my long career as a working artist. It is a huge milestone for me if you can imagine. We have only ever purchased one brand new car in 40 yrs of marriage, a Nissan hatchback manual transmission, our first Christmas together. We drove that little car until all it was good for was parts! LOL!

I’ve been told I drive like a little old lady so I’m thinking I’ll be just fine with a FWD. My Kia dealer 30 mi south in Winchester VA seems to have mostly FWD on the lot so that’s pretty telling.

I’ll be interviewing some locals to get their thoughts but as I gather from your very detailed post, there are many variables at play not the least of which is current technology and I understand the Telly has that in leaps and bounds!

 

[2020Telly]

@NCTelly great in depth explanation! Just read it to hubby over breakfast. Also shared comments and article by @alexdrums and @blitt Thanks to all!

We are located just off I81 between Winchester VA and Hagerstown MD and although our state does a horrible job maintaining and clearing roads, we are not in a rural area nor do we expect to ever be encountering the type of conditions shown in @blitt photo, and most definitely will not be off roading.

Our Telly will spend most of its time in our driveway, as a pleasure car if you will. Long distance vacations and shopping excursions via state and federal roads. It will be “my” car. I am purchasing it with income from my long career as a working artist. It is a huge milestone for me if you can imagine. We have only ever purchased one brand new car in 40 yrs of marriage, a Nissan hatchback manual transmission, our first Christmas together. We drove that little car until all it was good for was parts! LOL!

I’ve been told I drive like a little old lady so I’m thinking I’ll be just fine with a FWD. My Kia dealer 30 mi south in Winchester VA seems to have mostly FWD on the lot so that’s pretty telling.

I’ll be interviewing some locals to get their thoughts but as I gather from your very detailed post, there are many variables at play not the least of which is current technology and I understand the Telly has that in leaps and bounds!

Good luck! As you can tell I’m a huge fan of informed buying.

 

[2020Telly]

Here’s a general rule of thumb to consider . . . Where you live when winter comes can you pull up to any gas station and easily find very low temp rated windshield washer fluid and if you go to the supermarket can you buy de-icing salt? If the answer is no, then you will probably have more FWDs on the lot at local dealers. I always have to stock up when I drive back south with washer fluid because by the time I start driving north the following year the fluid will freeze if I don’t remember to drain and refill.

 

[stuffgeek]

I think I know the answer for me is AWD. I am with Alexdrums that my Honda Odyssey has issues with wheel spin with just a slight bit of moisture due to the torque/weight of that vehicle and I don't want to go through that again.

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[Sportshot2]

AWD or FWD different tires can improve the basic traction inherent in either design. I think it’s a stretch to say FWD with winter tires will be as good or better than AWD and all season tires. Which all season tire? There are good and poor performing A/S tires. A Michelin Defender LTX A/S tire on an AWD vehicle will outperform most FWD with winter tires.

Snow is not always the same. Sometimes it’s wet and heavy which makes for more slippery roads than the dry light snow which may blow off the roads easier.

Tire compound, sipping, and size all make a difference in snow. For snow you want a narrow and taller tire. Narrow to push through the snow easier and taller to increase ground clearance. There is no perfect tire for all conditions. More icy than snow covered roads give the advantage to studded tires but they are so hard on the road surface that many states made it illegal to use them. That’s where sipping and silica or other tire compounds have been proven to help improve traction In those conditions.

The tire chosen for AWD T’s is a comprise with more preference towards quiet ride than traction. While it is a good A/S tire I would rather of had the Michelin Defender LTX A/S which has better traction performance but tend to be louder on some surfaces.

The picture of driving on plowed roads doesn’t really mean the tires will perform well on unplowed roads. Ground clearance becomes very important in deeper snow conditions and the T’s is not that great.

 

[2020Telly]

Something doesn't quite line up in your statement.

A Michelin Defender LTX A/S tire on an AWD vehicle will outperform most FWD with winter tires.

But then later you go on to say "There is no perfect tire for all conditions." In snow, winter tires will do better than All Season for braking, handling and acceleration. There are many videos and articles you can search for that demonstrate this side-by-side comparison even with winter tires vs. all season tires in an ice skating rink on the same AWD vehicle, the winter tires are better grip. (They might be crappy on tread life, noise, and fuel economy.) It's a balancing act, you can do one thing really well but at the expense of 3 others, and all-seasons are a compromise all around. Many people who live in areas where it snows jokingly call all-season tires, "3 season tires" because they are no replacement for winter tires. All things being equal with the same tires in the same condition, AWD will do better in flat acceleration ONLY, but braking and handling will be identical to a FWD, the rest of car is the same. Same wheels, same motor, same braking, same suspension. When it comes to cornering, both the FWD and AWD use the same brake based TVCC system.

There is even some thought that when climbing slight inclines if there is no slipping, FWD might do better than AWD because on an incline you want all power on the front axle because that's where the bulk of the torque is needed. I'm not clear if you can have AWD on and the Telluride will determine it needs to be in FWD mode. That's where AWD loses me. Most of the driving, hauling, or towing I do, I prefer 100% up front and if AWD never gives me that because it is always on then I lose that ability. Remember the difference between regular AWD in the Telluride is 50% front / 50% rear axle power, but then snow mode is 80% front / 20% rear axle. If you are in a condition in light snow with snow tires and need to climb a slight hill you would want the AWD to behave like a FWD with 100% on the front axle. And when it comes to braking the brakes are the same so if you have winter tires in snow with more grip on the road a FWD weighs less so it will be able to brake at a shorter distance than an AWD that weighs more with all seasons that have less grip.

I agree that is there is no perfect tire for all conditions, that's why the idea of All Seasons in general is the ultimate compromise. That's not a bad thing, but it points to why tires are so important for the conditions. But you can't expect an all season tire to perform better in snow the same as you wouldn't expect it to be quieter than a touring tire on the highway, I also wouldn't expect it to have better fuel economy than a gas saving tire, or the grip on a clean road of a performance tire. It's a compromise all around. The Michelin Defender LTS All Season is a great choice and may do well in light snow, but there is no way that putting it on an AWD would outperform a FWD with winter tires in breaking, handling or acceleration. The AWD system is not giving you traction, it is only deciding how to make the most of the traction your tires have. If you improve tires, that's how you gain traction.

Remember that the modern AWD systems are not the same as 4x4/4WD systems. The AWD systems are reacting to the wheel slipping at a wheel and changing the power ratio at the axles to fix it. Where 4x4 directs power directing to the wheels individually. That means in an AWD if your car system senses slipping on the front axle it directs power to the rear axle to help you and vice versa. But slippery conditions aren't always in line with the axles. You might experience an ice patch under the rear left wheel and need power to the right rear wheel to get out of it more than directing power to the front and reducing power on the back. I believe that's why Kia implemented a torque vectoring cornering control system that is brake based. When turning if your inside wheel is having trouble, your TVCC system applies brakes to that wheel so that the outside wheel on the same axle can provide more power to make it past the condition and that happens with brakes at the wheels and not the axle. This is also standard on the FWD.

 

[Sportshot2]

I prefer 100% up front and if AWD never gives me that because it is always on then I lose that ability. Remember the difference between regular AWD in the Telluride is 50% front / 50% rear axle power, but then snow mode is 80% front / 20% rear axle.

Where we seem to disagree is that you state you need the torque on the front axel where what is really needed is traction. All the torque does you no good if you don’t have traction. The front end weight gives you more traction in FWD vehicles. Look at Pick Up trucks. Most RWD pick ups have terrible traction because more weight is on the front end and the traction available can’t overcome the front end weight in slippery conditions. Add some weight to the pick up box and it will greatly increase your traction. Years ago many Minnesotans added bags of sand to their RWD vehicles to increase traction.

The lock mode is the only time a T will have 50/50 Split. The Snow mode and lock will give you a 50/50 until it reaches a set speed and then it should switch to regular snow mode. Most Snow modes change throttle and transmission settings. More pedal will be needed for the same acceleration. Snow modes may also start in second or third gear instead of first gear.

I don’t know what exact percentage goes to each axel in every mode. Do you have a KIA chart showing that 80%?

The benefit of FWD over RWD has to do with weight distribution. FWD is better than RWD because you have more weight over the drive axel giving you more traction. The front tires are pulling you instead of the RWD vehicles which have to push the undriven front wheels through the snow.

 

[2020Telly]

I prefer 100% up front and if AWD never gives me that because it is always on then I lose that ability. Remember the difference between regular AWD in the Telluride is 50% front / 50% rear axle power, but then snow mode is 80% front / 20% rear axle.

Where we seem to disagree is that you state you need the torque on the front axel where what is really needed is traction. All the torque does you no good if you don’t have traction. The front end weight gives you more traction in FWD vehicles. Look at Pick Up trucks. Most RWD pick ups have terrible traction because more weight is on the front end and the traction available can’t overcome the front end weight in slippery conditions. Add some weight to the pick up box and it will greatly increase your traction. Years ago many Minnesotans added bags of sand to their RWD vehicles to increase traction.

The lock mode is the only time a T will have 50/50 Split. The Snow mode and lock will give you a 50/50 until it reaches a set speed and then it should switch to regular snow mode. Most Snow modes change throttle and transmission settings. More pedal will be needed for the same acceleration. Snow modes may also start in second or third gear instead of first gear.

I don’t know what exact percentage goes to each axel in every mode. Do you have a KIA chart showing that 80%?

The benefit of FWD over RWD has to do with weight distribution. FWD is better than RWD because you have more weight over the drive axel giving you more traction. The front tires are pulling you instead of the RWD vehicles which have to push the undriven front wheels through the snow.

Here's one of many references to snow mode that I have found: How does the 2020 Kia Telluride handle in snow?
"When the snow mode is selected, power is split 80 percent to the front wheels and 20 percent to the rear wheels. Lock mode will evenly distribute power to all wheels." However, what is not correct is that the AWD does not distribute power to the wheels individually, it splits power to the differentials on the axles, not the wheels. So take for example, in an 4WD or all electric car you can tune the torque response at each of the wheels, modern AWD systems tune at the axle in response to the wheel slip. That isn't always the response you need because you could be adding power on the wrong side and will need to get use to how the vehicle drives for your conditions.

What has continually confused me about the Telluride is that I read that the Kia Dynamax AWD system used on other cars that does give you 100% FWD mode if you need it. BUT, I have yet to specifically find official mention of the Dynamax system on the Telluride, which makes me think that Kia is doing something different on the Telluride, perhaps implementing something from Hyundai? I've seen reference to Dynamax AWD vs. something called "Active On-Demand AWD" and maybe that's the difference?

I agree the torque makes no difference if you don't have traction. But AWD does not give you traction, it is supposed to improve traction you get from the tires by reacting to slips if your tires can't grip the road for the conditions. Traction is improved by how much surface area you can get in direct contact with the road. It's why racecars have fat tires with no grooves, they need the traction to make the most force from the high torque. I think your example of a RWD truck is supporting my train of thought . . . as you pointed out if you add balanced weight to the truck bed, you can solve much of your traction problem by the down force giving your wheels more grip. But unbalanced weight on one side over the other (Left vs Right), could make things even worse. AWD does not give you downward force, weight and gravity do. But most of the time you buy a truck to haul stuff so that's less of a problem because a balanced load will add the force needed. With an SUV RWD is not great because you can load up the passengers but your are still trying to get more grip to equal the front because of the direct downward force of the engine, steering and suspension. An empty RWD truck or a RWD SUV with no cargo is going to be much worse traction than a FWD equivalent. However, an empty RWD SUV will likely do better than a RWD Truck with an empty bed because of the added weight of the back of the vehicle. On the flip side if you have heavier passengers on one side of the rear seat of the RWD SUV it will react different than if they were in the middle and it might be easier to balance cargo in a truck than passengers in an SUV. Ultimately, AWD does not give you downward force on the axle to give you more grip; better tires give you more grip. The AWD is just trying to manage the power to help with wheel spin when tires begin to slip. Take for example an AWD Telluride with the same tires on the rear axles but cargo and passengers on the left side of the vehicle could trigger the AWD to send more power to the front axle because the right rear wheel is slipping because all the pressure and grip is on the left rear where all the weight is when what you really need is to adjust left to right on the rear axle. Then add the self leveling shocks and after you start driving you won't even notice that there is a lean to the left, so your AWD will be working to correct something that would have been better by having the rear passenger sit in the middle or moving your cargo around. Fix the slipping more with better grip tires and a balanced load, you reduce your likelihood of wheel spin and your AWD is needed less.

Take for instance a snow grooming machine made to travel up and down a mountain. It has what looks like tank tracks on drive wheels the length of the vehicle for maximum traction. But the cab, motor, and plow are often at the front rather than the center often with what looks like a truck bed in the back. It needs the downward force up front to make it up a mountain. Then compare that to a tank design where the turret and cannon are mounted mostly in the center with the engine at the rear to handle recoil of the gun. The barrel of the cannon is not enough weight up front and the tracks will do fine over small hills but too steep a hill, the tank will tip over because of the weight not being up front and gravity pulling it back. Of course a snow groomer or a tank are extremes, but it's the same principles just at a different scale.

The only point I'm trying to stress is that AWD is not the silver bullet everyone is being told it is. It alone does not make your driving safer in the winter. The disclaimer next to every reference to AWD on the Kia site highlights this. I'm not debating that in certain situations it's good to have power on the back axle, but it's not as clear cut as people are led to believe that it will make you safer in all road conditions.

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[2020Telly]

Okay, I found an article that appears to describe Active On-Demand AWD on a Kia the same as Kia Dynamax. So if sounds like it is a little better than I previously thought. In Eco and Smart you basically have a FWD. If you switch to Snow Mode you get 80% up front and 20% to the rear, Sport gives you 65% up front and 35% at rear, and Lock gives you 50% front and 50% back. Still not like 4WD or an electric drivetrain that gives you control at each wheel when you need it vs. front to back, but presumably if you leave the AWD in Smart it will kick in AWD if it senses slippage. I still stand behind, the bigger safety advantage is to minimize the slipping and your AWD isn't as critical.

What Is Kia Active On-Demand AWD?
“Available active on-demand all-wheel drive helps provide enhanced driving performance by actively distributing torque between the front and rear wheels depending on road conditions and driver input. The system utilizes electro-hydraulic AWD coupling to precisely activate the multi-plate clutch plate, constantly redistributing the amount of power transferred to the front and rear wheels.

During normal driving, power is distributed according to the drive mode selected. Eco and Smart modes deliver 100 percent power to the front wheels. Comfort and Snow modes deliver 80 percent power to the front wheels and 20 percent to rear. Sport mode splits the power 65-35 percent between front and back. Lock mode delivers power evenly to all four wheels.”

 

[Tellurider AWD]

Torque steer can be mitigated with proper tire inflation, not mashing the gas pedal and just more conservative driving habits. If you are driving in rain or snow, I don't know that racing through the corners should be the goal. And it could also be caused by alignment issues. AWD might hide those tire and alignment issues. Pushing the pedal to the floor when turning . . . maybe the Stinger is a better car for you over the Telluride. Driving in rain or snow with an AWD Telluride and accelerating through curves with stock all-season tires still creates a safety concern that AWD may not overcome.

Im going back in forth deciding between a Kia Telluride SX Prestige or Kia Stinger GT2 AWD

 

[2020Telly]

I found this video and thought it was relevant to this thread. Now that’s a snow mode!