I bought an iD.3 to do a regular 160 mile trip in UK Winter, where temps could be around zero and sometimes we get snow. I like winter tyres for use when temps are <10C anyway, so bought a set of Nokian WR SUV 4 215/55 R18 95H tyres for winter time. The originals were Goodyear Efficient Grip 215/50 R19 93T, a very efficient tyre as it happens.
I decided to compare these, and did a couple of 44.4 mile trips up & down the motorway at identical speeds (70 on satnav), on the same day one after the other. Temperature was 13C, cold, but not that
cold. Motorway was slightly damp, with some drizzle, one of those gloomy depressing sorts of days!
I got 3.48 m/kWh on the Goodyears, and 2.73 on the Winters. This translated to 202 miles on GYs, 159 on Nokians, using the 100% SOC capacity.
So the GYs would be fine for my 160 mile trips in winter, the Nokians a bit marginal so would have to slow down somewhat.
So what I learnt is that I could expect about a 1/4 reduction in range when on winter tyres, which are not optimised for EVs & efficiency as far as I'm aware, versus the GYs which definitely are very
carefully designed to give a very low rolling resistance & good mpgs.
I don't know how these figures would have compared if this had been a snowy day at 0C, but I'm quite sure that Id' have had to slow down to probably 50-60 mph to keep my range up to the 160 mile mark if running winters.
In the end I sold the iD.3 as I didn't like the ergonomics one bit, and stuck with my Ioniq 38 what can also manage 202 miles in summer at 70 no problem, and I've learnt that I can also manage 200 miles in it (using 100% of the battery, so somewhat theoretical of course!) if I hypermile it by sheltering behind HGVs. In practice in winter at those 10C temps I'll be driving at fractionally faster than the HGVs, so a genuine 60 while they're limited to 58, and as the trip develops I can speed up a bit if my reserve (I usually see 180 on GOM at the start) is growing gently. Having a heatpump means that toggling heating on/off at statt of trip only changes the presicted range by 7 or 8 miles, an excellent result. without this I'd expect to lose more like 30 miles range in winter due to cabin heating. My Hyundai GOM is extremely accurate, I'd expect the Ioniq 5 one to be similarly good.
I was not impressed by the efficiency of the iD.3, despite a much larger battery 58 kWh useable than Ioniq 38.3 useable, the range was only about 25 miles more. Had hoped for a significant uplift of maybe 50 miles, but it wasn't there. I'm similarly not impresed by the efficiency of the Ioniq 5, no way will I consider that as a replacement for my 38! But the Ioniq 6 is another matter, sadly for me it's a saloon not a hatch, but otherwise it looks to be about the only affordable BEV around which has decent aerodynamics, I reckon I'd see 400 miles in summer no problem driving at 60 mph. SUV shapes are a disaster if you're looking for the most efficient BEVs, sleek coupes is what we need = better range, and cheaper running costs on the same trips. Tesla M3's have similar efficiency to the Ioniq 28/38s, again it's largely down to good aerodynamics.
Several things cut your range in winter - colder tyres are stiffer & harder to push along the road at walking pace upwards, so that affects you. Wet/damp roads, snow especially, all extra crud that has to be pumped out of the way, so that's a lot of energy. Speed's the biggest range killer, drag goes up quadratically with speed, so driving at 70 versus 50 means air drag's about (7*7)/(5*5) or 49/25, double the drag! My Ioniq 38 estimates are that Tyre losses (Rolling Resistance) is about 25% of the energy use in my trips, Wind resistance is most of the other 75%. Rolling Resistance goes up a bit with speed, but nothing like as dramatically as air drag does!
A further gotcha is that Li-ion battery capacity isn't a fixed set-in-stone value - I've seen reports of one such battery where the actual capacity drops 5% from a nice 20C ambient down to 0C freezing. So this is just another little-known facet to be noted.
Do your research carefully, find out what range others in your area are getting, whether they're using winters, how fast they go etc! My gut feeling is I'd want a mfr of at very least 300 mile claimed range to be certain of doing 200 in winrter in bad conditions, especially if I had to run winters. Ioniq 6 will definitely manage this, even on winters - it's significantly better than Ioniq 5 range-wise. Something like 389 miles claimed?
If the AWD Ioniq 5 does 266 miles in summer, good conditions, I'd expect this to drop to (160/200) of this on winters at similar road temps so that's now 213 miles on winter tyres with good road conditions. Add in some real snow, or torrential rain, and thats going to nose-dive. That 200 mile trip with ?only one? Rapid charger en-route sounds risky to me. A major power-outage, or regular scheduled maintenance, or damn great lorry blocking the access etc, could make it a very stessful topup, I always want to know there's a decent plan B Rapid somewhere else within range.
The RWD 303 mile range becomes 240 using same guesstimates with winters on in good conditions, I think I'd take that option myself. I'm nowadays happy starting out on a 200 mile trip in summer, mfr's claimed range is 196, because I know I can recover my losses by slowing down as necessary. My winter trips of 160 miles see me arriving with between 20 & 40 miles on the GOM, as the last bit I'll be speeding up to 70 or 75 as I've only got 20 miles to go with 50-60 in the tank, and any unexpected diversions/motorway closures thx to accident etc cannot possibly push me out-of-range at that stage.
My wife suffers rage anxiety, I don't, but I'm the one driving & I know how I can adjust to suit - she has to rely on me! She wasn't too impressed when we returned home, turtle picture on the dash, after short trip in rain, only had 1% left in the GOM! Her fault for insisting we dash off as fast as poss for a shopping trip, I'd wanted an extra 30 mins on the wallbox!
I discovered the final 10% on the GOM seems to vanish a lot faster than the first 10% we generally think the GOM isn't perfectly linear in miles range, rather that it's linear in the qty of amp-hours the battery is dishing out, but because the voltage of the cells drops suddenly as they get drained, the power of those amp-hours is reduced. I think H should may have compensated a bit for this, but it's perhaps a very difficult thing to quantify the voltage curve precisely, while the car's moving, regen's happening, ambient as well as battery temperature's fluctuating, precise state of any ageing/degradation of the cells is another variable, etc, so it's not surprising if they measure amp-hours rather than watt-hours - a far easier task.