The only way to correctly test energy efficiency is by having two similar cars driven on the same roads at the same time over a reasonable long distance.
This test was conducted using two almost identical 2023 White Model Y Performance vehicles built in the Shanghai factory within days of each other. Both had covered over 1,600kms in the first week of ownership. Both had aircons set to 22°C. Both had cold tyre pressures of 42psi. Both had two occupants. It is crucial to note that neither car used the Williams Supercharger to navigate to and thus battery preconditioning was NOT used to avoid contaminating the results. During the test, the cars were driven no closer than 60 metres at highway speeds with the biggest gap being approximately 400 metres. Each car drove the front position for half the journey.
Cars were driven at the speed limit (max 110km/h) as much as possible with overtaking of slower traffic only conducted on designated overtaking lanes. Luckily traffic flow was generally good during the whole test.
To be clear, the test was conducted mostly on the Albany highway, a coarse road surface that’s consumes plenty of energy and is often used by Tesla drivers visiting the Great Southern.
Over the total 272km test (136kms south, 136kms north), the Performance model Y with factory fitted 21 inch Überturbines averaged 178Wh/km while the Performance model Y with the 19inch Gemini rims and hub caps (acquired from a new standard range model Y) averaged 158Wh/km, an improvement of 11%. That’s not a typo, that’s eleven percent with every other aspect of the two cars being identical.
There’s two main factors that cause the difference in energy efficiency: The 21inch Überturbines have what could be described as “sticky” Pirelli tyres, great for putting down the power and torque of the dual electric motors under extremely hard driving, but energy hungry in general driving. The 21 inch wheel/tyre combo has less smooth tyre surface and more rough wheel surface on the outside of the car. The Gemini wheels have more smooth tyre surface and a fairly smooth hub cap so airflow at higher speeds is less interrupted. If you’re a City Slicker, the 21 inch Uberturbines are fine. If you plan on long distance driving away from reliable DC charging, the energy wasted may be an issue.
Model Y Performance 21″ Überturbines
Model Y Performance 19″ Gemini
Leg 1 31 km
212Wh/km
195Wh/km
Leg 2 105 km
168Wh/km
149Wh/km
Leg 3 105 km
200Wh/km
175Wh/km
Leg 4 31 km
105Wh/km
95Wh/km
Total 272km
178Wh/km
158Wh/km
TOCWA Note: Distance per Leg is approximate
Leg 1: Byford to Albany Hwy T junction. Moderately uphill, average speed 64 km/h
Leg 2: T junction to Williams Woolshed Supercharger. Moderately downhill, average speed 97 km/h
Leg 3: Return Williams Woolshed to T junction. Moderately uphill, average speed 102 km/h
Leg 3: T junction to Byford. Moderately downhill, average speed 71 km/h
Conditions: dry 22°C to 29°C, light winds. Start time 9.30 am, finish 1.15 pm.
Überturbines (left photograph), Geminis (right photograph). Both “Since Charge” screens did not reset to zero as per normal after Supercharging???
This test was conducted by Harald Murphy and Rob Dean, two of the most experienced long distance drivers in Australia.
The much-needed WA EV network is here! Geraldton and Northampton are the first two sites to have been commissioned and, as of today, both are now operational. Geraldton boasts two 150kW fast DC chargers which are ready to replace the temporary 50 kW TOCWA (Tesla Owners Club of Western Australia) DC charger that has been a godsend for hundreds of EV road trips. Northampton has one 150kW DC charger as well as a 7kW AC charger.
One of two 150kW Kempower DC chargers at GeraldtonWA EV Network Map
EV drivers eager to hit the country roads during these school holidays, will take comfort in knowing that each 150 kW charger shares its capacity across two CCS2 cables which means that up to four EVs can charge at any one time. If two EVs are sharing a single charger, the 150 kW capacity will be shared between the two cars, however, if the two EVs are spread across the two chargers, drivers may be able to draw up to the full 150 kW rate, which is good for a peak charge rate of approximately 1,000 km an hour in WA’s most popular EV, the Tesla Model 3 Rear Wheel Drive. This means that the majority of charging sessions are expected to take approximately 20 to 25 minutes, which is not only the minimum recommended break duration on long road trips but also just enough time to use the bathroom and grab a drink, coffee, or a bite to eat.
From left to right: Carl Van Heerden – Synergy, Sandra Giry – Synergy, Liam Dunphy – HEC, Pushpa Gurung – Synergy, Diarmuid O’Donovan – HEC, Jong Yiing Yang – Jetcharge, Harald Murphy – TOCWA, Guy McHugh – Synergy, Mary Davadra – Synergy, Sean Henderson – Jetcharge.
Geraldton and Northampton are the first of a total of 49 charging locations that will span the state, enabling EV drivers to fast charge every few hundred kilometres from the Northern Territory border, along the coast, all the way to the South Australian border. The WA EV Network has been funded by the WA State Government and will be available on the Chargefox network, however, a simple swipe of a credit card will be sufficient to get the electrons flowing. (This feature is not currently activated but it is coming soon.)
Originally the brainchild of Professor Thomas Braunl, the WA EV network, which comprises of Synergy and Horizon Power chargers, will add to the existing charging assets, including Tesla’s Supercharger network, the RAC Electric Highway, as well as other networks and dozens of commercial, donated, or crowd-funded chargers, such as the 50 kW AEVA DC units in Lake Grace and Ravensthorpe. You can find the WA EV Network chargers on the Chargefox app or for a complete listing check out www.plugshare.com
Full House at the First Test-Charge with four EVs charging simultaneouslyThe Northampton site at 202 Hampton Rd, Northampton A successful test-charge in Geraldton. The Geraldton site is located at 31 Foreshore Dr, Geraldton.The cafe across the road from the Geraldton charger will be a handy place to take a break on long road trips.
The inland road is called the Great Northern Highway, it’s sealed all the way until it joins the North-West Coastal Highway approximately 60kms South of Port Hedland, for the most part it’s in reasonable condition. All year round this is a major heavy haulage transport route that although not as busy as the Coastal highway will on occasions carry some massive low loaders with over width mining equipment, fortunately the highway is fairly straight with plenty of room to pull over and allow wide vehicles to keep their tyres on the sealed section. Tourists generally avoid this road with the exception of August-September when Caravan and RV traffic increases significantly due to some spectacular Wildflower blooms. I would not recommend travelling before mid April due to the heat and also the small chance of flash flooding that may cut road access for up to a week. From mid April onwards the days are generally dry and warm with nights getting cooler as each week ticks towards July, when clear nights can be close to freezing.
Is there much to see? Not a lot but there are a few unique sights, the small towns of Mount Magnet, Cue and Meekatharra still carry the wide roads and beautiful Stone buildings from the late 1890s. Newman started life in the late 1960s so isn’t the prettiest of towns but the tour of the Mount Whaleback Iron Ore Mine is well worth the time.
Charging: We drove through this area up to Tom Price and back across to Marble Bar in April 2018, there’s a number of locations with 5 pin 3 phase outlets capable of charging a Model 3 or Y at 11kW (3x16amps) the problem is most of the ones we used weren’t suitable for regular use due to access issues. Despite a number of years of thumb twiddling the shire councils in the area are finally realising that being omitted from the state governments EV charging network requires them to change from procrastinating to progressive, hopefully a few of the shire owned and convenient 3 phase outlets will be accessible sooner rather than later, until then the trusty 15amp caravan socket is the plan B and not as bad as you would think when a trip is planned wisely.
Suggested itinerary:
Dalwallinu– 245kms from Perth, the Old Convent has a 32amp three phase, it’s best to ring ahead for good will. It’s very likely you’ll charge for approximately 3 hours as the next useful charging stop is over 300kms north. If 3 hours in Dalwallinu is a bit too much to bear a stop in New Norcia or Moora while charging from 3 phase will add some different scenery without adding more than a few minutes to the journey.
Paynes Find– the old roadhouse has a small dusty campground out the back with 15amp caravan sockets, these are untested but if they run an RVs aircon they’ll charge an EV.
Mount Magnet tourist park- 317kms from Dalwallinu. This is a good overnight stop with some grass sites, a secure location and not too much traffic noise after 8.00pm. If you arrive before 6.00pm and plug straight into 15amps it’s possible to add a genuine 280kms of range by 8.00am the next morning. This location does have a 32amp three phase wired in and ready to go, it’s just waiting for the shire to approve its use.
Cue – 80kms from Mount Magnet and well worth a walk around the townsite. Stop in at the Queen of the Murchison for a coffee and more.
Meekatharra – 115kms from Cue. The shire are currently on the look out for a easy to access 3 phase in the meantime the caravan park is secure with a few 15amp options.
Karalundi – 60kms from Meekatharra. This location offers a shady campground with powered sites. Amongst the dry scrub Karalundi is an oasis due to a useful underground water supply, the caravan park is a side gig for the boarding school, my choice would be to stay overnight here rather than Meekatharra so as to shorten the drive to Newman.
Kumarina Roadhouse – this is a small roadhouse and campground 232kms north of Meekatharra that’s a welcome stop for a takeaway meal. The Camp ground has a number of usable 10/15amp sockets.
Newman – 367km from Karalundi, 190kms from Kumarina RH. This town has 3 phase but once again access is difficult, hopefully now that nearby Tom Price and Paraburdoo both have DC chargers the East Pilbara shire may show more interest in EV charging. In the short term 15amp overnight will do the job.
Tom Price – 277kms from Newman. This is a tidy little town that’s worth the detour, it’s also a good base for visiting Karijini. Tom Price has a near new 25kw DC charger that’s a real bonus for visitors.
Paraburdoo – 81kms south of Tom Price, this little town has a 50kw DC charger which is handy for anyone deciding to head back to Perth via the Nanutarra roadhouse and Carnarvon.
A few tips:
Carry a full size spare tyre.
Try and avoid driving after dusk
Drive with caution during the day as most roads north of Mount Magnet are unfenced with plenty of stray Cattle.
Don’t plug in without asking and always offer to pay for charging.
The short answer is it’s often unlikely but it’s not always about the money so please read on.
To clarify a solar specific charger is a device that detects home solar input and can be set so an EVs charging amps will not be higher than the excess solar available, for instance if the sky becomes cloudy and solar input reduces so will the EVs charge input.
If you have a neighbour that loves calling your Tesla a “Coal burner” there’s no better way to shut down the claim than by charging 100% from solar power, a solar specific charger is a good way of achieving this. As your neighbour is already too thick to understand electric motor efficiency they won’t be wise enough to work out you’re not saving any money by charging via a sometimes expensive piece of equipment.
Perth is the sunniest capital city in Australia – Yep, even sunnier than Brisbane in the sunshine state. During daylight hours the sun shines on average two thirds of the time in the Perth area so installing a device that only allows solar to charge an EV is redundant for two thirds of the time.
Combined Installation and unit cost – This varies by a large margin so it’s best left to a case by case basis, what is important is to get an accurate dollar figure on the difference between a fully installed solar specific charger and a fully installed “dumb” (generic) unit that continues charging at the same amps. For instance if Tesla have provided you with a free Gen2 UMC that you plan to plug in to an existing 10/15amp wall socket your installation plus unit cost is zero dollars. If you’re considering a $750 Tesla destination charger (HPWC) with a $750 installation cost your total cost is $1500. Keep in mind $750 is an example as installation costs are wide ranging.
Now as an example if you get a quote of $2000 for the solar specific charger plus $750 installation the extra upfront cost to charge directly from solar is between $1250 and $2750.
How long will the payback on investment be?
Once you have a fixed and trustworthy quote and you also have a firm understanding on how many kilometres you plan to drive per day using home charging use the below chart to do some calculations. If you’re not sure about driving kilometres yet a good guide is this, the average passenger car travels 38kms per day in Australia.
I’ve factored in a unit cost of 30 cents from the grid and the 2023 feed in the tariff of 3 cents per unit, this provides a potential saving of 27 cents for every kWh of solar going direct to the car. Keep in mind that In Perth across a whole year the sun is shining 2/3s of the time anyway.
The decision to install a solar specific charger is up to you, just think through these questions:
Do you drive enough distance per day to justify it?
Do you plan to charge from home during the day on an almost daily basis?
Do you have enough excess solar?
And does the units warranty period match your expectations?
The most recent Tesla Superchargers in Karrinyup, Williams and Margaret River are V3, the 2017 built Eaton Superchargers are V2. Those who’ve charged at Eaton will have noticed each charging stall has two cables, the second cable is a retrofitted CCS2, that’s the one 99.9% of WA Tesla owners will use. V3 chargers are vastly superior as each stall is capable of delivering up to 250kw depending on the vehicle battery type and size, starting percentage and battery temperature. The V2 stalls at Eaton have a maximum output of 145kw for each pair of stalls (1A&B, 2A&B, 3A&B), meaning if you plug into stall 1B not long after a car has plugged into 1A your initial charging speed will be very slow. The trick is to avoid parking next to another car if possible. The slower charging speeds at Eaton are only a nuisance on busy Saturday mornings on a long weekend. To get the best charging speed set navigate to the Supercharger and the car will automatically preheat the battery pack before arrival, on cool days this makes a significant difference to the starting charge rate. A second tip for the fastest charge rate is to arrive with approximately 10% range and depart with 60-80% depending on the distance to the next chargers. Arriving with only 10% is advice I would never give with any other type of charge point in Australia, the fact is Tesla Superchargers are vastly more reliable than any other DC chargers in this country.
Eaton Supercharger cables.
Why not charge to 100%?
Basically 80 to 100% takes longer than charging from 10 to 60%, wasting time defeats the main purpose of a Supercharger. Be aware that when a Supercharger gets busy charging may get limited to 80%, the phone app will provide a notification, if charging past 80% is absolutely necessary it can be overridden. You can read more here: Charging to 100% is a waste of time.
Don’t overstay you visit- Once your car has completed charging you have 5 minutes grace to move the car, failure to do so will result in a backdated per minute surcharge added to your Supercharger account, as the phone app will pre warn you there’s no excuse.
