AWD better in Midwest

[Motomax]

Granted, these are artificial conditions, but you don't see mainstream EVs do better in the roller tests done by TFLCar or Car Question. In general, it seems like cars like the Mach E or Model Y do worse than Subarus or Audis when perhaps that shouldn't be the case. If the more precise control over axle speed that can then be modulated side-to-side was such an advantage, why don't we see better results? Most AWD EVs need to be pushed off the rollers with 3 wheels artificially "stuck."

Awd in its basic form is no better than 2WD in certain loss of traction situation, only 1 wheel will spin freely. 4WD locks the front and rear difs together, which means in the same situation 2 wheels will spin freely. Certain AWD vehicles use limited slip center difs which allows 2 wheels to spin (Subaru is especially good with a 50:50 power split f-R).
Awd EVs if programmed correctly can act exactly like a 4WD system (minus the lowgear).

here’s the catch, every single one of those vehicles will fail the 3 roller traction test because at best they can only drive two wheels.
so how do you pass the test? You use the brakes! If you can apply the brakes to the spinning wheel, it will allow your differential to send power to the wheel on the other side. It acts like a less effective locker.Vehicles that don’t have 50-50f-r split will not do as well in this test either. It just won’t be able to push enough power to that one wheel.

AWD EVs can definitely pass this test.Plus, the ability to control the front and rear motor would actually make it much easier since they only need to brake one wheel. The only thing better would be 3-4 motors. They just need to have a traction control system that knows how to handle it.

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[DrSteveBrule]

Awd in its basic form is no better than 2WD in certain loss of traction situation, only 1 wheel will spin freely. 4WD locks the front and rear difs together, which means in the same situation 2 wheels will spin freely. Certain AWD vehicles use limited slip center difs which allows 2 wheels to spin (Subaru is especially good with a 50:50 power split f-R).
Awd EVs if programmed correctly can act exactly like a 4WD system (minus the lowgear).

here’s the catch, every single one of those vehicles will fail the 3 roller traction test because at best they can only drive two wheels.
so how do you pass the test? You use the brakes! If you can apply the brakes to the spinning wheel, it will allow your differential to send power to the wheel on the other side. It acts like a less effective locker.Vehicles that don’t have 50-50f-r split will not do as well in this test either. It just won’t be able to push enough power to that one wheel.

AWD EVs can definitely pass this test.Plus, the ability to control the front and rear motor would actually make it much easier since they only need to brake one wheel. The only thing better would be 3-4 motors. They just need to have a traction control system that knows how to handle it.

I totally agree that EVs can pass the test. I understand the open diff + braking concept. I don't understand why Tesla, with their frequent, iterative software updates, hasn't sorted this out yet. Ford probably has bigger fish to fry right now. Maybe the roller tests are not scenarios that they target, but they seem like reasonable approximations of real-world predicaments. I've been stuck many times in FWD cars when one wheel loses traction thanks to the open diff and no modern traction control. I think FWD with good traction control programming (or a limited slip diff) and snow tires is probably more capable in winter conditions than most AWD systems.

 

[Motomax]

I totally agree that EVs can pass the test. I understand the open diff + braking concept. I don't understand why Tesla, with their frequent, iterative software updates, hasn't sorted this out yet. Ford probably has bigger fish to fry right now. Maybe the roller tests are not scenarios that they target, but they seem like reasonable approximations of real-world predicaments. I've been stuck many times in FWD cars when one wheel loses traction thanks to the open diff and no modern traction control. I think FWD with good traction control programming (or a limited slip diff) and snow tires is probably more capable in winter conditions than most AWD systems.

I think it comes down to the purpose of the vehicle. Many people assume that AWD is designed for bad weather/snow which isn’t always the case. A sports car AWD system is designed for handling and quick acceleration(Mach e GT?) which is much different then say a 4Runner that’s designed to drive with two wheels off the ground.
Sure they could program a snow mode and overbuild the brake controller, but that cost money. Most people probably aren’t taking their Tesla on an ice rink.

 

[fixed]

i'm in an RWD select with continental vikingcontact 7 winter tires. where i go nordic ski is up a dirt road that they often "forget" to sand/salt in the winter. as a result, it turns into pure ice. haven't had any issues climbing that hill on winter tires yet this year.

however, the awd escape (stock continental all seasons) they gave me as a loaner for recall work really struggles. it's good at starting on flat ground from a stop...better than the mach e on winters. but it's also pretty bad at going in a straight line on a snowy road and even worse at turning.

braking performance seems pretty similar, probably because the escape is a thousand pounds lighter.

 

[mlhunt856]

i'm in an RWD select with continental vikingcontact 7 winter tires. where i go nordic ski is up a dirt road that they often "forget" to sand/salt in the winter. as a result, it turns into pure ice. haven't had any issues climbing that hill on winter tires yet this year.

however, the awd escape (stock continental all seasons) they gave me as a loaner for recall work really struggles. it's good at starting on flat ground from a stop...better than the mach e on winters. but it's also pretty bad at going in a straight line on a snowy road and even worse at turning.

braking performance seems pretty similar, probably because the escape is a thousand pounds lighter.

They always say tires are more important than drivetrain design for driving in snow.

 

[bosbruce]

I totally agree that EVs can pass the test. I understand the open diff + braking concept. I don't understand why Tesla, with their frequent, iterative software updates, hasn't sorted this out yet. Ford probably has bigger fish to fry right now. Maybe the roller tests are not scenarios that they target, but they seem like reasonable approximations of real-world predicaments. I've been stuck many times in FWD cars when one wheel loses traction thanks to the open diff and no modern traction control. I think FWD with good traction control programming (or a limited slip diff) and snow tires is probably more capable in winter conditions than most AWD systems.

I largely agree with that. However, apart from the ability to change direction of power by steering the power, RWD with good traction control programming or limited slip diff and snow tires is probably more capable than FWD with same for 2 reasons : (1) while FWD ICE vehicles often have 60+% weight over the driven wheels, that quickly shifts to < 50% when attempting to ascend steep slopes, while RWD vehicles get more weight over the driven wheels as the slope gets steeper (I've had to drive FWD cars backwards up very steep snow covered roads at times, while with RWD even on extreme perf summer tires and traction disabled I could keep the tires spinning with enough friction to wag the tail of an old G37 6MT Coupe up a steep snow covered road passing an accord and a civic who were sliding backwards probably on slightly worn all seasons). That said, it was a bit dicey and I will not be late changing to winter tires again! (2) For FWD Ice vehicles (or even EVs like my old Bolt), it is far less easy to add more weight over the driven wheels as throwing a bag of sand over your engine (or Bolt electronics) is clearly unadvised but works well for most RWD.

 

[Pushrods&Capacitors]

Reading this thread and got a little chuckle about ICE rwd vehicle traction control performance vs. EVs. Some makers have better TC programming than others. For sure. Here is what GM/Holden came up with for my ‘14 SS Sedan - stock was 415/415 hp/tq, I’m at about 465/465 right now. This run was on Continental ExtremeContact Sport SUMMER tires in 39F conditions on a regular road, no grip of track surface or burnouts. Traction Control on.

For reference, the best our 4X has done from 0-30mph so far is a 2.1. I know it’s apples/oranges, but, GM, Porsche, BMW, MB all have TC programming down so well now that on the street you’re a fool to turn it off thinking you’ll be quicker. Track is a different story altogether.

 

[jhalkias]

Why turn off one pedal? (note...I just drove in the snow yesterday in our Jeep Gr. Cherokee with 2 pedal and it had a learning curve....I was so so accustomed to 1 pedal)

The weather this past week in Ohio has been awful. In normal conditions I drive in 1pd exclusively, but in this weather, I drive in Whisper, 1pd OFF, and L. This still gives me a good bit of the regen that you get in 1pd, but less. There are times when you hit an icy or slushy patch that you want to "coast" and not brake at all to prevent a slide, and I just do not feel as confident in 1pd in those situations.

 

[tuminatr]

The weather this past week in Ohio has been awful. In normal conditions I drive in 1pd exclusively, but in this weather, I drive in Whisper, 1pd OFF, and L. This still gives me a good bit of the regen that you get in 1pd, but less. There are times when you hit an icy or slushy patch that you want to "coast" and not brake at all to prevent a slide, and I just do not feel as confident in 1pd in those situations.

I did that too until I put dedicated winter tires on the car now 1pd on and in unbridled.

 

[jhalkias]

I did that too until I put dedicated winter tires on the car now 1pd on and in unbridled.

What tires did you get? It seems to me that the Blizaks have pretty good reviews.

 

[tuminatr]

I bought Vredestein Wintrac Pro 225/60/18 and a set of select wheels. Bilzzaks are good, advantage to the Wintrac is lower rolling resistance and they perform much better on the days that there is no snow.

 

[mlhunt856]

I bought Vredestein Wintrac Pro 225/60/18 and a set of select wheels. Bilzzaks are good, advantage to the Wintrac is lower rolling resistance and they perform much better on the days that there is no snow.

I don't know about their winter tires but I suspect they're an underrated brand based on how much better the 235/45R-19 Vredestein Quatrac Pro XL 's I put on my 2019 Ford Escape AWD 2.0 Ecoboost were than the OEM Continental CONTIPROCONTACT - SIZE: 235/45R19 I replaced.

 

[ChuckA]

I know my car isn't worth a damn for resale because everyone here feels like they need to have AWD, so I stick with AWD for the benefits and safety, and to hold more value.

AWD is necessary in the snow belt for safety. The only thing I ever added to my cars for resale value was a sunroof. Hate them, never opened it.

 

[Tom L]

First, RWD EVs have FAR better traction than typical ICE RWD vehicles, in part because the weight is usually 50% over the driven wheels, and in part because traction control is hundreds of times more precise since direct motor can help control things way faster/better than the typical ICE RWD where long drivetrain takes eons to react (even in manual tranny) though brakes are about as quick.

Second, as someone else mentioned, having a good set of winter tires almost always makes you safer than having AWD in the snow. And, if you need more traction in accelerating you can always put a sand bag or two in the trunk to give you closer to the traction of AWD.

Third, I chose RWD in my Mach E because I wanted Premium and I wanted to get the added range (IIRC AWD took away 15 miles) of RWD and also still get the $2500 MA EV rebate keeping the sticker under $50k. I would have gotten AWD mostly for the performance advantage if it didn't hurt range so much and if choosing it didn't also lose me that rebate in addition to the price bump. (Adding AWD+ bigger battery to me also just makes the car way too heavy)

Fourth, with RWD I can turn off traction control (man that setting is finicky though... not sure why sometimes it refuses to change even when I'm in P) and do the smoothest, quietest donuts in a snow covered parking lot of any car I've ever owned. Can AWD / GT / GT PE Mach E do donuts? Certainly should be possible but I'm not aware of that ability.

Everyone who is concerned about RWD in mild winter conditions with an EV should read what bobsbruce posted. This explanation is right on the nail head. RWD in an EV vs RWD in an ICE car are not comparable in snow due to the differences in weight distribution, although many people persist in generalizing incorrectly from old experiences. The one advantage AWD will give you in snow is starting traction (and climbing hills), but for improved steering and braking you need winter tires regardless which drive train you have.

 

[tuminatr]

Everyone who is concerned about RWD in mild winter conditions with an EV should read what bobsbruce posted. This explanation is right on the nail head. RWD in an EV vs RWD in an ICE car are not comparable in snow due to the differences in weight distribution, although many people persist in generalizing incorrectly from old experiences. The one advantage AWD will give you in snow is starting traction (and climbing hills), but for improved steering and braking you need winter tires regardless which drive train you have.

I don't agree with the part that RWD is better in an EV than an ICE. After all, a regular ICE ford mustang has the same traction control system as the Mach E. The ICE Mustang would have an advantage that at very low rpm it makes less torque. ICE mustangs are built to handle/corner so typically have a very low center of gravity. Maybe a tie or slight advantage to EV in center of gravity. A modern mustang GT is about 3800 lbs. so the Mach E has more weight, but the ICE GT would probably have wider tires. Modern winter tires it's about biting edges (sypes) so wider tires equate to more grip.

I do know a few people who drive modern ICE mustang GTs in the winter here in MN as well as in North Dakota. Their experience is close to bobsbruce they say with winter tires and if you are careful, it's enough.

If anyone questions if RWD in the Mach E is better for traction than AWD they can't be serious. Everyone knows or at least they should AWD provides superior traction for acceleration, in the MME

I think the real question that is being asked here is this. In a MME is RWD enough for the Midwest, or is AWD worth the extra money? I don't know and would need to run some tests and/or need to drive an RWD and AWD in the snow to give you a definitive answer. Ideally with and without winter tires. And even there because much of the driving experience is feel and comfort level it could be a different answer from driver to driver.

My gut tells me that if even the average driver got a chance to drive both comparably equipped RWD and AWD in the same wintery conditions they could tell the difference and would want the AWD in the Midwest.

I do agree with your comment that winter tires will help with handling/cornering and breaking AWD will not help with that.

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