Disclaimer: At Airdrie’s destination for hybrid and EV service, we’re car nerds – it’s part of what makes us good at our job! This article is based on some experimenting with our 2022 Tesla Model 3 Performance and is intended to showcase the impact that wheel and tire choices have on electric vehicle range. Are we recommending that owners of performance EVs discard their factory rubber in favour of something less sticky? Probably not. (But please read on to discover the noteworthy difference that these changes can make.)
The Tesla Model 3 is one of the world’s most popular electric vehicles. For 2022, the Model 3 is offered in three flavours: the base rear wheel drive with an EPA estimated range of 430 km, the dual motor Long Range variant with 580 km of range and the dual motor Performance with 507 km of range. These last two models share the same 82 kWh battery with 75 kWh of usable capacity. The Performance model’s reduced range comes thanks to its increased horsepower, big Brembo brakes, larger 20″ wheels and sticky Pirelli performance tires.
We asked ourselves: What would happen if you installed the 18″ aero wheels and all season tires from a Model 3 Long Range on a Model 3 Performance? Could the more powerful car achieve the same range? Would this provide a “best of both worlds” situation with oodles of #HRSPRS and class-leading efficiency? Unfortunately, it’s not that simple. None of the 18″ OEM Tesla wheels fit the M3P because of its larger wheel hub design and clearance issues with the larger brakes. However, there are some 18″ aftermarket wheels that will. We decided to have some fun and build the most range-focused wheel and tire package possible, and then pit it against the original Performance wheels in a range test.
Aero Wheels for the Model 3 Performance
For our experiment we chose the FAST EV01+ wheel from Canadian supplier Fastco. This is a lightweight flow formed wheel with removeable aero inserts. In several different independent tests, the EV01+ demonstrated nearly identical efficiency to the OEM Tesla aero wheels. They are also hub centric for the Model 3 Performance, providing a factory-level fit without adaptors or centering rings. This makes them safer and less prone to vibrations than multi-fit wheels.
The Most Efficient Tires
For the rubber, we selected the Michelin Energy Saver A/S, currently the lowest rolling resistance tire available in the 235/45R18 size. These tires are even more efficient than the Michelin Primacy MXM4 tires fitted to the Model 3 Long Range from the factory.
(It appears that Tesla was willing to trade some efficiency for the quieter, smoother ride offered by the Primacy.)
Weighing 22.4 lbs each, the EV01+ wheel is almost 10 pounds lighter than the hefty OEM Uberturbine wheel. While three pounds of that weight savings is negated because the smaller wheels necessitate a taller tire, the new combo tips the scales at 7.1 pounds less (per wheel) than the factory setup. This alone will translate into a small efficiency increase. Normally this reduction in unsprung weight would also improve acceleration, but any celerity gained here was neutralized by our eco-friendly tires’ lack of traction. (More on that later.)
The Range Test
On the day of our testing, conditions were perfect: 20°C with no wind. We chose a 30 kilometer stretch of Highway 2 between Airdrie and Carstairs for the test. Tire pressures were all set to 42 PSI. We drove the test route in both directions, noting the average efficiency recorded on the “25 km” screen of the Tesla Energy app at a specific location at the end of each run. This means that the first 4-5 km, including merging onto the highway, weren’t included in our numbers and we were comparing the exact same stretch of highway (within just 5-10 metres) every time.
For the first test, we set out to achieve the best efficiency possible with both sets. The route was driven with Autopilot locked at 100 km/h and climate control turned off. Under these facile conditions, the Model 3 returned commendable efficiency of 129 Wh/km with the factory wheels and we wondered if we’d actually see any improvement with the new wheels. As it turns out, we sure did – see the table below. The second test was run under more “real world” conditions at 120 km/h and the climate control set to 19°C. In both tests we managed better efficiency driving the route in the northward direction because of slight decrease in elevation heading toward Carstairs. Full results are below:
|Test 1 – Uberturbine||119 Wh/km||139 Wh/km||129 Wh/km|
|Test 1 – EV01+||99 Wh/km||120 Wh/km||110 Wh/km|
|Test 2 – Uberturbine||149 Wh/km||166 Wh/km||158 Wh/km|
|Test 2 – EV01+||126 Wh/km||148 Wh/km||137 Wh/km|
Based on the 75 kWh battery capacity, the switch to 18″ EV01+ wheels and Michelin Energy Saver A/S tires results in a theoretical range increase of 101 km at a speed of 100 km/h, or 72 km at 120 km/h. These increases of 17% and 15% respectively mean that using these wheels, our Model 3 Performance should indeed travel just as far as a Model 3 Long Range. (Which you’ll recall has a 15% longer range according to the US EPA.) This difference in efficiency is also consistent with what we’ve seen from other manufacturers. For example, the BMW i4 M50 loses 71 km or 16% of its range moving from 19″ to 20″ wheels with more performance-oriented tires.
Long Range Test
We decided to test the FAST Wheels/Michelin combo on a road trip from Airdrie to Vancouver, BC and back. This would give us a chance to further evaluate the Energy Savers’ effect on range while getting a better feel for their road manners. Over the 2,094 kilometer journey we averaged an impressive 131 Wh/km with three people on board and both luggage compartments full. Previously, we’ve never been able to best 148 Wh/km during similarly conservative driving through the mountains. Of course this isn’t a legitimate comparison in a controlled environment, but the difference was enough to be noticeable nonetheless. Aside from efficiency, how did the new tires and wheels fare? We’ll get to that next.
The Big Asterisk
So far these tire and wheel changes sound pretty good, right? Well, not so fast. Before you email us to order the Michelin Energy Savers for your own M3P, it’s important to note that aside from their efficiency, these tires are a downgrade from the factory Pirellis in almost every other way. Their wet traction is noticeably worse, and their dry traction isn’t much better. That’s no surprise because traction and rolling resistance are opposing characteristics: you give up one to gain the other. The Energy Savers turn this 500-ish horsepower sedan into a drifting machine capable of power-sliding corners through glorious clouds of tire smoke. Surprisingly, the Michelins are also noisier than the Pirellis at highway speed and imperfections in the road surface such as cracks are transmitted more sharply to the cabin.
If nothing else, this whole experiment certainly illuminates the compromises that auto manufacturers have to make when choosing a tire for their vehicles.
What about gasoline/diesel vehicles? Could I do something similar to improve my fuel economy?
With fuel prices as high as they are today, why aren’t automakers fitting their internal combustion models with aero wheels and low rolling resistance tires? The answer is twofold: in some cases they already are, but they’re doing it sparingly because these wheels and tires offer a much lower benefit on gasoline vehicles. That’s because internal combustion vehicles are only 20%-40% efficient at turning the energy contained in the fuel into movement of the vehicle. Most of the energy is lost as heat, so automakers have focused most of their efforts on improving their engines instead, where the largest mileage improvements can be made.
Gasoline vehicles also carry far more energy on board: a 60 litre (13 gallon) tank of gasoline contains more energy than six Model 3 Performance batteries combined. With the majority of that energy being wasted already, small efficiency improvements are less perceptible. On the other hand, electric cars are 75%-90% efficient at using battery power to propel the vehicle forward. This means that air and rolling resistance changes are more noticeable when it’s time to “fill up” the electric vehicle.
As our little experiment demonstrates, tire and wheel choice can drastically affect your electric vehicle range. This underscores the responsibility that we have as automotive professionals to help our clients choose the right tires for their vehicle. We know this doesn’t always happen, especially in the large tire chain stores where poorly trained employees may just input your tire size into a computer and quote the first tires that come up.
If your electric vehicle needs new tires, we can help! We drive EVs, we understand them and we’d love to help maintain yours.