An AWD platform can also offer improved handling and turning radius by applying different amounts of power to each wheel. See Audi's Quattro and Acura's SH-AWD as examples, or even the comments about turning radius on the Model X.
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Is an AWD Model S Necessary?
- Thread starter NigelM
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Vger
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I believe both are true. Power is limited in the 60kWh and smaller batteries by limited parallel current paths. Power is limited by the motor in the 85kW non-perf.
It is still possible that the regen is dialed back from maximum that the battery can take due to stability issues (potential rear wheel lockup and spinning the car). We know this is the case on the roadster. Jerome Guillen told me that the Model S alphas had software control of regen by the driver through a large range. He said that set to the max it was very aggressive, much more than the roadster. They obviously dialed that way back for production, and gave the user only two choices-- moderate and mild.
So, it seems quite possible that an AWD Model S would have stable regen braking that could be much more aggressive. Sure it is better to coast when you can, but if you are pounding through the mountain twisties, more regen is better than more friction braking on efficiency.
One other advantage no one else seems to have mentioned on this thread is tighter turning circle. When I rode in the Model X Proto, it could turn much tighter than the Model S in the same spot of the road. This through the "magic" of all-wheel steering (torque steer), despite it's longer wheel base.
I'm sure that the Model X at the reveal was 2 Wheel Dr., because they were building it on the Model S skateboard. Tesla will introduce the four-wheel-drive version of the Model X on or soon after the initial release date.
W8MM
R1.5 #325 + Mdl S #01380
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.
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gg_got_a_tesla
Model S: VIN 65513, Model 3: VIN 1913
Tesla simply says "With a rigid body structure, nearly 50/50 weight distribution and a remarkably low center of gravity, ..."
Model S Features | Tesla Motors
Model S Features | Tesla Motors
W8MM
R1.5 #325 + Mdl S #01380
Thanks so much for the quick reply!
This just confirms that the Model S snow traction will be not as good as an FWD car and not quite as bad as most RWD cars, but not nearly as good as an AWD car. The reason we decided to forego reserving a Signature Model S three years ago was based on the eventual availability of AWD in the future. Alas, this now seems like a pipe dream and I am pretty nervous about relying on a 50/50 weight distribution RWD car to provide the same level of winter mobility as the Audi S4 it will notionally replace.
I can't quite believe that going up snow-covered hills around here with full winter tires in a RWD Model S will even approach the S4 shod with Continental DWS all-season tires.
Color me disappointed.
I used to live in Ohio and Iowa and got through the winters fine in a FWD car with all season tires. Winter tires are always the smarter choice in areas when it snows though. I would think with dedicated snow tires on the Model S, you'll be fine. Most of winter driving has to do with what kind of tires you have and how you drive (speed up to stop sign then apply breaks vs. easing off the accelerator and coasting to the stop sign for example). I'm sure AWD will be a little better in some circumstances but for the other 10 months in Cincinnati, the Model S would be a better choice. And you can heat your car remotely (even with the garage door closed) in the Model S.
W8MM
R1.5 #325 + Mdl S #01380
I'm not surprised that an FWD car would do well enough around here in the winter. But, I used to own a BMW 750 a dozen years ago, or so. It had about 50/50 weight distribution and I had outfitted it with the most advanced winter tires of the day. It wouldn't go up my driveway reliably with the combination of snow and ice that is so common here. One time I got stuck off the driveway in my front yard and needed a 4WD tow truck to extract me.
Lately we haven't had that sort of winter, but they can come back unannounced.
BTW, how do you find the performance of your Roadster's A/C in Texas? Our R1.5 isn't so pleasant in August hereabouts.
The 2.5 seems to do much better than the 1.5s in the heat from what I understand. The AC doesn't cut out too much but is kind of weak and takes a long time to cool the cabin. The Model S should be much better.
Maybe during those times of big snow you can weight the back of the car down with sand (not ideal I know). Salting your driveway is an option too I guess but not the best for the driveway. I think the traction control on the Model S should be more advanced than your old BMW but we'll see once people actually get the car into winter conditions.
They seem to have some eco-friendly options as well for melting ice
http://www.scotwoodindustries.com/dry-products
Maybe during those times of big snow you can weight the back of the car down with sand (not ideal I know). Salting your driveway is an option too I guess but not the best for the driveway. I think the traction control on the Model S should be more advanced than your old BMW but we'll see once people actually get the car into winter conditions.
They seem to have some eco-friendly options as well for melting ice
http://www.scotwoodindustries.com/dry-products
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Agreed, but what if the front wheels didn't provide torque through the turn and only ramped up the torque as the car straightened out? I would assume the benefit would be the feel of a RWD car into the turn, but with the pull of a 4WD car out of the turn.
Traction control and the smooth application of torque (both things an EV can do easily and better than the best ICEs) to the wheels plays a bigger role than FWD or RWD would. In fact (unless you are backing up) a RWD vehicle should go up a slick hill better than a FWD vehicle, all other things being equal.
The Roadster has a 60/40 weight distribution. Good for a sports car. (goes to 50/50 on braking/turning) Remember that battery is inches from your back. Only the PEM is over the wheels. A forward driver (and passenger) weighs much more.
I read somewhere (I can't find it now though) that Model S is 55/45 weight ratio. Pretty neat for a sedan w/ RWD
which means .... besides being pretty awesome for most aspects of driving IMO
It should Drift!
which means .... besides being pretty awesome for most aspects of driving IMO
It should Drift!
Seems pretty normal. The E350 is 53/47. http://www.guideautoweb.com/en/specifications/mercedes-benz/e_class/
I had almost forgotten that Tesla hinted at an AWD version Model S three years ago. Hopefully they follow through, though now it doesn't seem likely till after the Model X launches.
I would prefer an AWD over Rear Wheel even though I watched the Model S handling video and was really pleased. As I have said I can turn around in the morning going to work which I have done twice now but in the afternoon a place to stay is $200 a night. So if I get the Model S I keep the RX400h AWD to see how I like the S in snow. If I get the Model X AWD I sell the RX400h of course if I get a S AWD I sell the RX400h.
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