Is an AWD Model S Necessary?

[PatP]

My experience in the snow was very positive. In my limited snow driving in California, I was able to go around other cars stuck in the snow with 21 inch wheels and continentals! From my experience, the S is probably better than most or all two wheel drive vehicles in the snow. Tesla's traction control is better!

I'm quite surprised when people are saying this. I have the best winter tires on my S (Nokians) and I found my S was below average in terms of traction in the snow.

Next winter, I'll make a video comparing my Model S, my Volt (with the same tires) and my BMW X1 (also on Nokians). I can tell you in advance that the Model S won't keep up with the Volt (and of course the BMW will leave both cars in the dust).

 

[brianman]

I'd also like Steve's response.

 

[AnOutsider]

I'm quite surprised when people are saying this.

You're not the only one. I guess it might also depend on the types of cars previously driven and the environment.

 

[Raffy.Roma]

My experience in the snow was very positive. In my limited snow driving in California, I was able to go around other cars stuck in the snow with 21 inch wheels and continentals! From my experience, the S is probably better than most or all two wheel drive vehicles in the snow. Tesla's traction control is better!

Actually a car with winter tires and a good ESC and traction control has a good behaviour on the snow. But if on top of this you add AWD the behaviour of the car is even better of course.

 

[mpt]

I'm looking forwards to AWD to see acceleration match the Roadster... Then I'm in!

 

[stevezzzz]

I would have thought about $10k. However if Performance Plus retrofit is $13k, I guess it will be more than that....

Brianman, I'm with patp on pricing. But I'm not holding my breath that an AWD conversion will be possible: if and when Tesla offers an AWD version of the S, I may have to bite the bullet and swap out my Sig, though I don't want to.

 

[wycolo]

I view the S as over-powered and thus under-ranged. But that is me, out here. Therefore I see an X with significantly more range (at least as an option) and less power (as option) to go along with that inevitable AWD. And who does not salivate at the mere thought of AWD by Tesla out in the snow and mud. :love:
--

 

[Bipo]

Including me they are 4

Include me also. At the moment I have a quattro so AWD is a must-have for me.

 

[JRod0802]

I view the S as over-powered and thus under-ranged. But that is me, out here. Therefore I see an X with significantly more range (at least as an option) and less power (as option) to go along with that inevitable AWD. And who does not salivate at the mere thought of AWD by Tesla out in the snow and mud. :love:
--

I believe the limiting factor in determining power is the amount of KWh of the battery. So range and power should either go up together or go down together.

 

[neroden]

I'm quite surprised when people are saying this. I have the best winter tires on my S (Nokians) and I found my S was below average in terms of traction in the snow.

I haven't tried it on snow (next winter perhaps). The S is pretty good on *ice*, though.

- - - Updated - - -

AWD will be necessary when buyers stop waiting for their cars and cars start waiting for buyers. When this happens, AWD happens also.

I wouldn't be so optimistic. Unlike a lot of the stuff people are asking for -- which is basically easy -- AWD is actually hard. I'm pretty sure Tesla went with a RWD car just so they didn't have to interlock the drivetrain with the steering system. To do AWD, they *have* to interlock the drivetrain with the steering system, and it's *actual work* to engineer that. I'm sure AWD will come eventually, but given that Tesla has a whole lot of other stuff to fix, I am certain it's on the back burner.

 

[Lloyd]

I'm quite surprised when people are saying this. I have the best winter tires on my S (Nokians) and I found my S was below average in terms of traction in the snow.

Next winter, I'll make a video comparing my Model S, my Volt (with the same tires) and my BMW X1 (also on Nokians). I can tell you in advance that the Model S won't keep up with the Volt (and of course the BMW will leave both cars in the dust).

I'm sure you do much more winter driving than I. I trust your experience here.

 

[W8MM]

I'm quite surprised when people are saying this. I have the best winter tires on my S (Nokians) and I found my S was below average in terms of traction in the snow.

Next winter, I'll make a video comparing my Model S, my Volt (with the same tires) and my BMW X1 (also on Nokians). I can tell you in advance that the Model S won't keep up with the Volt (and of course the BMW will leave both cars in the dust).

I agree with your observations. Traction control only makes the best of what traction is possible. In a 50/50 Front/Rear weight balance car, only 50% of the available traction is available to one set of wheels. In an AWD car, 100% of the wheel traction is available. Front-wheel-drive cars are OK in lots of snow situations because as much as 2/3 of the weight is concentrated over the driven wheels and, therefore, 2/3 of the possible traction is available. The Model S is close to 50/50 and is therefore operating at half of the possible traction of AWD and only 3/4 of the possible traction of some front-heavy FrontWD cars.

Traction control doesn't magically make traction, the best systems only conserve it. Traction in snow is dominated by tire choice and the percentage of vehicle weight (mass) bearing on the driven wheels. Traction control only limits wheel spin when the driver asks for more traction than physics allows. The best traction control systems fight the driver's inputs to a draw and keep the car from spinning its wheels to no advantage and possible loss of control. Directional control is a good thing to preserve, but directional control does nothing to move a vehicle up a snow-covered grade; only raw traction can do that.

The Model S has a good traction control system, but it only makes the 50% of possible traction more available than a car without traction control. It does not magically generate the traction of an AWD vehicle.

(BTW, I'm a 20+ year member of the Society of Automotive Engineers)

 

[Doug_G]

@W8MM I agree, but that's not the whole story. The Model S, with appropriate tires, has adequate traction in most situations.

FWD (and AWD) vehicles have one key advantage in extremely slippery conditions: you can pivot the drive wheels. When you're stuck and the car has trouble moving forwards, the rear wheels of RWD vehicles tend to slide sideways. This can make it impossible to extract yourself. The same thing happens to FWD vehicles but you can swivel the drive wheels to compensate. This advantage was very obvious one evening last winter, when we had a huge blizzard and our plowing service never showed up. All the cars needed shoveling and pushing to get out of the parking lot, but the Model S definitely had a harder time of it because its rear wheels sliding out.

Traction and stability control systems have pretty much fixed the problem of the front wheels locking up, resulting in loss of steering control. But they can't fix the back sliding out on you.

 

[W8MM]

@Doug_G Maybe you're used to relatively flat terrain. Where I live, we have serious grades to mount. I gave up on RWD when my BMW 750iL with real winter tires couldn't get up my driveway. I tried to back up and take a run at it, but after a few deteriorating cycles, I ended up in my front yard and required an AWD tow truck to winch me out. The BMW had about the same weight distribution as the Model S. My wife uses the "S" as her daily driver with the Tesla winter wheel/tire set and if there is serious snow, we take my AWD Panamera. We were lucky this winter and didn't have many bad snow days.

 

[Doug_G]

@W8MM, We do have some hills here, and we had a horrible winter for driving conditions. I've had some issues starting up from a standstill on an icy incline, with the TC overdoing it so much that the wheels don't turn! But turning off the TC got me moving.

Interestingly, the Roadster is 60% rear weight, and it's pretty amazing on snow/ice.

 

[W8MM]

Interestingly, the Roadster is 60% rear weight, and it's pretty amazing on snow/ice.

For getting under way, RWD and rear weight bias are a good combination. Not only is there more mass concentrated over the drive wheels (like FWD w/front weight bias), but the suspension's weight transfer onto the drive wheels under acceleration (squat) helps even more when starting from rest. FWD cars lose a little traction on start-up when the car's nose lifts up a bit. VW Beetles were the king of RWD traction in their day.

 

[tander]

I don't understand how traction control can make an RWD Model S perform like an AWD car. FWD cars can do well in winter because they almost always have a majority of their mass concentrated over the front (driven) wheels. Our Roadster 1.5 (#325) did reasonably well with snow traction because the battery pack mass was positioned toward the driven wheels. I am skeptical of the winter performance of the Model S (reservation #R44) because just looking at the chassis pictures leads me to believe that the weight balance will be near 50/50 front-to-rear. Dedicated winter tires (mountain snowflake symbol) may or may not be enough to provide sufficient propulsion if the driven wheels don't have the lion's share of the car's mass pushing them on to the pavement. Has anyone been able to find a specification for the Model S that points out the front/rear weight ratio? I have looked and can't.

+1 Better yet anyone have an MS and a Subaru, how do they compare in winter conditions?

 

[AnOutsider]

+1 Better yet anyone have an MS and a Subaru, how do they compare in winter conditions?

No subarus, but we have audis (quattro), and the S definitely pales in comparison.

 

[BryanW]

+1 Better yet anyone have an MS and a Subaru, how do they compare in winter conditions?

We live on a hill, against the mountain in Utah. We have a 2008 Subaru Outback with all season tires. We have never needed true snow tires for the Subaru because it does fine with climbing into our neighborhood no matter the snow conditions. The Roadster with winter snow tires does well, but not as well as the Subaru. The Model S with 19" wheels and stock Goodyear all seasons does ok in the snow but not as well as the Roadster with its snow tires.

The traction control on the Model S works well, but climbing the snow covered hill in front of our house the traction control slowly brought the Model S to a complete stop, it then started rolling slowly backward. Our Subaru is the only car I'm aware of in our neighborhood that has never had a problem climbing this hill, and our neighborhood has many 4x4/AWD vehicles. I once got home at 2am with 9-12" of unplowed snow on the road to find a neighbor in his 4x4 truck stuck spinning his wheels trying to get into the neighborhood. I had him follow in the tracks of my Subaru which allowed him to get through the steeper parts of our neighborhood.

So yeah, the Model S is ok in the snow but it isn't a Subaru. If the AWD option had been avail I certainly would have gotten it. Once Tesla works our the AWD S and X, I believe they will be the best snow handling vehicles on the road.

We are looking forward to the AWD X!

 

[bint2k]

No subarus, but we have audis (quattro), and the S definitely pales in comparison.

As in the model S is worse? Do you use winter tires AnOutsider?