EV's and their ability in the snow

[austinsmirk]

So we've a Leaf- in the recent snow I had cause to drive it a bit, so its on its factory eco treaded Dunlop's- eg no cross treading. no cross climate type pattern. I figured it would be awful- tyres would simply not grip.

However it was pretty amazing- far more so than my diesel car, with its cross treaded, Uniroyal Rainsport tyres fitted.

perhaps an obvious question/statement: but is the technology/traction control type systems powering the wheels, simply far superior to an ICE car and thus it produces far superior traction in the snow ?

Should point out I'm in Yorkshire, adjacent to the moors, at the top of silly hills and so on (think Haworth type countryside).

I know a proper 4 x 4 and winter tyres (on any car) will still always be better, but its food for thought re: the advantages of EV's driving in such conditions.

[Evanivitch]

Too many variables.

[super7]

I have an Outlander PHEV and was very impressed in the ability in the snow.

Without the engine, clutch and all that stuff, and running of just the front and rear motors, the car's control at low speed and setting off was way better than my old Shogun. I'm sure it's helped by the fact that it's automatic and naturally pulls away as soon as the brake is released, but the CVT gearbox makes for smooth acceleration and also helps big time....

[njd27]

What I found when driving my Leaf is that although there's a lot of torque at slow speed, when the wheels do begin to spin it does it in quite a benign way - where a FWD ICE car would often start a bit of axle tramp a Leaf would just spin up the wheel slightly. I guess the engine assembly can be mounted quite rigidly since it doesn't produce much vibration.

Also, there aren't any gears/clutch so it's much easier to control the power at low speed. You notice this particularly when negotiating hilly roads with hairpins and multi-storey car parks.

And there's plenty of weight!

[Shilvers]

It's the weight

EVs tend to have narrow tyres to help with the range. Combine those tyres with the extra weight of an EV and they're very sure footed in the snow.

[travel is dangerous]

it's not just the weight, it's more that the torque output of the motor can be varied much more rapidly than with an ICE. There are also no torque spikes (e.g. one revolution is four separate 'bangs' on a 4 cylinder engine).

[a7x88]

travel is dangerous said:

it's not just the weight, it's more that the torque output of the motor can be varied much more rapidly than with an ICE. There are also no torque spikes (e.g. one revolution is four separate 'bangs' on a 4 cylinder engine).

It's actually worse than that - remember a 4 stroke engine needs 2 complete revolutions to complete the cycle. With a four cylinder 4 stroke you would get ~2 power strokes per RPM, so even worse for torque spikes!

[anonymous-user]

a7x88 said:

travel is dangerous said:

it's not just the weight, it's more that the torque output of the motor can be varied much more rapidly than with an ICE. There are also no torque spikes (e.g. one revolution is four separate 'bangs' on a 4 cylinder engine).

It's actually worse than that - remember a 4 stroke engine needs 2 complete revolutions to complete the cycle. With a four cylinder 4 stroke you would get ~2 power strokes per RPM, so even worse for torque spikes!

Utter rubbish. It’s the weight and thin tyres that make it better than a similar sized car that’s lighter and has wider tyres.

Look up ‘flywheel’ if you really believe what you wrote is correct.

[page3]

We too found our Leaf rather good in the snow. Even better when we used ‘eco’ mode. If they renamed it ‘snow’ I’d use it more!

[Chris-S]

Torque spikes are definitely 'a thing', it's why manufactures developed the much hated dual mass flywheel. Worse on diesels than petrol. Done mainly to protect the gearbox in manual vehicles, so unlikely to be an issue in an auto unless the converter is locked up.

https://en.wikipedia.org/wiki/Dual-mass_flywheel

Maybe more of a comparison with say a Tesla S or X and similarly sized (weight) ICE vehicles? Tesla tend to put big wide tyres on their cars.

[FiF]

They must have improved a lot. Years back we had two Prius on manufacturer loan. Nobody ever used them, usually because when needed the 12v battery had gone flat. Anyway hearing tales of how crap they were in the snow we took one out down a country lane. Managed to get it such going downhill, yes you read that right. Front wheels dropped into a hole and could not go forward, it would try to drive, but then there was a sort of click and drive would be lost, sort of like an all or nothing limited.

However stuck it in reverse and it just powered out. Naturally it could be argued that the weight transference to the front axle by facing down a slope might have had something do with it, however further experiments on the level showed that the control system definitely had different psrsmeters for power delivery in reverse compared to forward drive. In reverse the traction was relatively decent, even on the hard as rock eco tyres.

[chandrew]

I drove an i3 BEV for 2 winters in lowland Switzerland on winter tyres. The performance was better than I expected but not as good as the AWD cars that I was used to. I never had an issue with sliding but starting up a hill involved wheel spin a few times (something I've not experienced in an AWD). A bigger issue was battery performance in the cold (especially when leaving it outside and coming back to find 30km less range than I left it with)

Went back to a petrol car (340 xDrive) when I moved to the mountains due to a combination of shortage of charging options & battery performance concerns in the -25C we get at night. I'm expecting the former to be fixed soon and the new bigger batteries to compensate the latter so expect the next car to be an EV.