Updated with EPA figures!

TLDR – The Ioniq’s class-leading combination of fast charging, very low drag and battery thermal management make it a very interesting alternative to the Leaf 30, or even the “new” Leaf 40 if you want to use the car for long trips. For lower speeds, day-to-day use and commuting the new Leaf will have greater range than the Ioniq simply due to greater battery capacity. For longer trips, see this head-to-head test with the Ioniq, Leaf 40 and Leaf 30:




We went shopping for a 30kWh Leaf, and ended up buying an Ioniq electric. Why? And why not wait for the new Leaf 40?

On paper, the Hyundai Ioniq electric is a close match for the outgoing Leaf 30, with a twenty-something kWh battery and a similar sized body. It’s also a similar price in the UK, at twenty-something thousand pounds. However that’s where the similarities end. The Ioniq has some killer features, and it’s the combination of these in an affordably priced package that makes the Ioniq electric more of a Tesla Model 3 competitor in certain areas, than a Leaf competitor:-

  •  Very low drag; Cd of 0.24 and a low body, this leads to:
  • True 70mph motorway cruising with decent range
  • 100kW-class charging
  • LG Chem battery with air cooling and heating (as required by LG Chem)
  • Very high regen power, equal to the motor power of 87kW (this is unusual!)

The battery capacity, a useable 28kWh, is the same as a “Leaf 30”, and modest compared to the new Leaf 40kWh. However we don’t yet know the useable capacity of the new Leaf, but what we do know is that the Leaf is not as aerodynamic as the Ioniq.  At higher speeds, I anticipated that the difference in range between the Ioniq 28 and Leaf 40 will be very small. Around town and at lower speeds, the Leaf 40 will have a range advantage, because aerodynamics play a smaller part in power consumption. Nissan acknowledge this on their website, where they estimate the range for the 40kWh Leaf for a number of use cases. This is the one for motorway use:


This confirms to me that the “new” Leaf 40 is only slightly more efficient than the old model. 110 miles divided by 40kWh is 2.75 miles/kWh. I am, however, surprised that the difference between summer and winter isn’t more than that, 125 divided by 40 is 3.1miles/kWh.

The EPA efficiency and range figures report that the new Leaf 40 is no more efficient than the old model, it only goes further because of the increase in battery capacity. Note that the “city” and “highway” figures here are from a test cycle of driving, so can’t be compared with my figures elsewhere in my blog, at constant 70mph for example.

I also calculated the battery size (since EPA report the efficiency and range) and the battery capacity is approx 38kWh, which matches what some had observed from Nissan’s energy storage offering at 38.4kWh.

Compared with an Ioniq, this means that the new Leaf has 36% bigger battery but is 21% less efficient.


Keeping the battery warm (and cool)

The other advantage that the Ioniq has over all Leafs to date is thermal management of the battery. Existing Leaf owners are only too aware of the significant range loss in cold weather. If the car isn’t used for a day or two in winter, the battery cools and capacity (and range) drops. I’ve found that the Ioniq doesn’t suffer so much from this effect, with 120 miles range even after a few cold days.

The Ioniq has electric heaters that keep the battery warm when the car is plugged in. Reports from owners who have delved into the car’s systems to get battery temperatures are that the pack is maintained at 10-15C. This maintains the battery capacity, and so range, in cold weather. The Leaf on the other hand, has battery “protection” heating in some markets, just not the UK. These are designed to protect the battery from very low temperatures and don’t switch on until below -10C.

The Ioniq also has battery air cooling, probably only significant in very warm UK summers or with repeated rapid charging. An air intake at the back seats takes air through the pack to a fan in the boot, and warm air is is exhausted outside. I noticed the air intake is opposite the air conditioning grille for the rear passengers, so can take advantage of air-conditioned air in summer. The Leaf battery relies on air passing under the car to stay cool, and this works OK in the UK in practise at least for the Mk1 car. It might explain why Nissan have not gone for rapid charging rates over 50kW as yet.

Early reports suggest the Leaf 40 seems to be suffering with battery temperatures restricting the “rapid” charge rates to as low as 17kW in warm weather after driving, even gently. This seems to be simply a characteristic of the battery; Nissan understandably do not want the battery to overheat, causing permanent degradation and warranty claims.

I was seriously considering a Tesla as our next car until I realised just what the Ioniq specs, taken together, meant. A small battery, motorway-capable car with next-generation rapid charging. Ultimately what put me off used Teslas wasn’t just the price and the “will they survive the Model 3 production hell?” question – it was the sheer width of a Model S, which would limit my commuting routes !

Consider a long motorway trip. You want a car that can travel at a real 70mph when possible (not that often in the UK unfortunately), and when you or your bladder chooses to stop, it charges quickly at standard chargers you can find at all services. I’d say if it charges in the time it takes to take a leak and drink a latte, that would be nigh-on perfect.

The Tesla Model S can probably do this, of course, if you can get your hands on at least £45k for a second-hand one. It has a low drag (0.24 as it happens) and Supercharging at a growing number of locations. These charge at up to 120kW, with one car connected to a supercharger, or reduced to 60kW, with two cars connected and sharing the supercharger (did you know that?) I anticipate the imminent arrival of the cheaper (£35k+) Tesla Model 3 to mean that superchargers will increasingly be busy, and so shared.

So, how many “miles per hour” of charging can your car get? That is, for each hour hooked up to a rapid charger, how many miles range do you get? The calculation depends on the efficiency, in miles travelled per kWh, and the charging rate. Let’s compare 3 contenders that can rapid-charge from DC at motorways: there are other cars, but these illustrate the point.

Ioniq: 4.3 miles per kWh, 60kW charging (derated from 70kW peak), 258 miles per hour

Leaf Mk1: 3.25 miles per kWh, 40kW charging (derated from 50kW peak), 130 miles per hour (Nissan’s USA site says “30 minute charge = up to 88 miles”)

Model 3s: Tesla claim “130 miles per 30 minutes”, that’s 260 miles per hour

…so you can see that by this measure, the Ioniq is in Tesla Model 3 territory, and way ahead of the Leaf. Unfortunately, in early 2018, the highest output charger you’ll find is 50kW, but higher power chargers are on their way from Shell, Ionity and Ecotricity. Even at 50kW, available today, the Ioniq charging rate becomes 215 miles per hour, significantly faster than the Leaf.

Put another way, how long does it take to add 100 miles of charge? Regardless of the range of your car, at some point you’ll want to add enough expensive motorway “juice” to get you home, where it’s inevitably cheaper to fill up. Slowing down on the motorway to eke out another few miles is just… so 2016.

Time to fuel up for 100 miles, assuming fastest charging rate used:

Ioniq: 23 minutes

Leaf Mk1: 46 minutes

Leaf Mk2, 40kWh 45 minutes to 2.5 hours (depending on battery temperature, driving style and ambient temperature)

Model 3: 23 minutes

So, we could drive the Ioniq for around 2 hours on  a typical UK motorway, keeping up with the traffic rather than the lorries, stop for 20-25 minutes for a coffee and resume. It also means that even a 10 minute stop can add a useful amount of range to enable you to “press on” to an appointment, or just to maintain a contingency in case of the unexpected. That’s a massive step forward compared to a Leaf Mk1. Even a new, 40kWh, Leaf will be stuck with a 50kW max. charger.

But, but I hear you cry: the Model 3 has a big battery and can do 220 miles! Yes, the ranges of these cars 3 are different, and IF you can keep within the range of your car then you’ll probably get there sooner than one that has to charge- assuming you don’t have to slow down much. And as long as your bladder can also manage it. What matters is how much of your journey you spend waiting to charge. Lets compare the Ioniq with the Tesla. As the Ioniq has a similar charging speed as the Model 3, and probably similar efficiency, on a long 200+ mile journey, you’d need to stop more often, for half the time- but overall spend the same amount of time charging. As the Leaf is less efficient and has half the charging speed, you’ll spend a heck of a lot more time charging on long trips.

Ultimately, though it pains me to say it, this makes the Leaf Mk1 look more like a City car than a long distance one. Unless, of course, you can live within its range and charge at destinations – while you sleep or do something more interesting than watching the Kilowatt-hours tick by.

As it happens, these cars I used as examples use 3 different rapid charger connectors! Yup, that’s right. The Ioniq uses “CCS”, Leaf “Chademo” and Tesla uses the proprietary Tesla connector that’s some variant of the “Type 2” connector (for rapid charging). CCS is the European standard connector, so it seems to be the most future-proof way to go. However, Nissan have invested in Chademo for Vehicle-to-grid applications and have a fleet with Chademo, so will resist changing to CCS. Nissan have already moved from Type 1 to Type 2 for the new Leaf’s AC connector for slower charging, though so will presumably help with owners upgrading- who won’t have a home charger that fits the new car.

By the way, most rapid chargers today can’t charge two cars with different connectors at the same time. CCS and Chademo are electrically similar but have different plugs – and so probably share the power electrics.

The Ioniq’s class-leading combination of fast charging, very low drag and battery thermal management make it a very interesting alternative to the Leaf 30, or even Leaf 40 if you want to use the car for long trips. For lower speeds, day-to-day use and commuting the new Leaf will have slightly greater range than the Ioniq, simply due to greater battery capacity.

One thought on “The Ioniq electric: more like a “Model 3” class car than a Leaf

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