So here is my review of the Model S silver non-performance car I drove in Chicago. This review is presented in terms of whether it passes or fails my expectations, particularly with respect to the Volt and in areas that haven’t been extensively covered by others. To restate the obvious, the amount of time allowed was sufficient for a
drive, but not for a
test drive, yet, I tried my best.
Pass
1.
Accelerator pedal mapping: Accelerator pedal mapping is done well and allows for good control at low speed.
2.
Turn radius and steering feel: My perception of the turn radius agrees with the published 37 ft. While this is more than the Volt’s 36 ft, I give it a pass considering its monster size. Steering feedback was good enough for me and I can see myself using both the comfort and sport power assist settings at different times.
3.
Turn signal blip: The turn signal flashes three times after a blip of the stalk.
4.
Max acceleration into a right turn from a full stop: Chassis stiffness, suspension, tyres and traction control all need to work together to make this successful. The result was on par with the Volt. The Model S has less chirp from the inside front tyre, but probably only because it is rear wheel drive, while the Volt is front wheel drive. Considering that the Model S is much bigger and heavier than the Volt, I give this test a pass.
5.
Cruise control: The cruise control is really well done. When on, it displays the speed set point as a bug on the outside of the speedometer circle, just like the bugs on the IAS or HSI on an aeroplane. Resume and increment/decrement reacts immediately and adjusts the speed assertively without any undershoot or overshoot. The increments are 1 mph (see more below).
6.
Acceleration: 0 to 60 mph came in 6.5 seconds and 0 to 100 km/h in 6.8 s. However, as can been seen from the Graph 1 below, the motor overpowered the brakes when applying power against the brakes, causing the timer to trigger prematurely by not more than 0.3 s. So, 0-60 mph in 6.2 s and 0-100 km/h in 6.5 s are probably more accurate. There were four people on board with an estimated mass of 290 kg. With only an 80 kg driver on board, we can expect 0-60 mph in 5.6 to 5.7 s which is close enough to the claimed 5.6 s. Acceleration in the peak torque band was 0.47 g compared to 0.39 g (two occupants 140 kg) or 0.40 g (single occupant 85 kg) in the Volt. While this difference is noticeable, it is not dramatically better, and neither my wife nor I said “wow” or “oh my god”. The
important difference, though, is that the Volt starts losing torque at 50 km/h, while the Model S keeps going until 76 km/h (according to the specs page, and confirmed here). At 100 km/h, the Volt has only 0.15 g acceleration, while the Model S still has more than 0.3 g. This will allow highway manoeuvres with much more confidence.
7.
Air suspension: The air suspension really does make a difference to the ride quality. I also suspect that it contributes greatly to the quiet interior.
Undecided
1.
Regeneration: I was hoping that the Model S would have stronger regen braking than the Volt. What I felt during the drive was that it was initially weaker than the Volt, but then became stronger as the car slowed. Looking at the graph below, this is confirmed. From 65 to 45 mph it was 0.13 g and limited by the 60 kW charge limit. Below that speed it is a constant 0.15 g. The Volt starts at 0.15 g and ramps down as it slows. I prefer the constant deceleration of the Model S, but would’ve preferred it to be at least 0.20 g.
2.
Immediate access to air recirculation: This is a big irritation in the Volt. It has 37 buttons on the centre panel for everything under the sun, except for recirculate, which is the one thing that you need immediate access to when driving through a cloud of dust or behind a smoke billowing truck. The Prius has a recirculate button right on the steering wheel, which is perfect. The Model S does not have a recirculate touchon in the A/C controls area, but it does have an A/C on/off touchon, which does turn off the fan. I suppose this is better than nothing.
Failed
1.
Door close action: I have written before (
Nissan Leaf) that the Volt has the best door close action of any car I have interacted with. The doors will close themselves after just a slight nudge out of the hold detent. The model S has an extra hold detent close to the closed position that effectively “catches” the door before it closes. And there isn’t enough spring action left to close it after moving it out of this detent. After all the fuss and bother from Franz about the door handles, I am quite upset that they couldn’t get the door close right. Big Fail.
2.
Displays in SI units: The firmware in the beta unit in the store has an option to display distance in miles or km. However, nothing visible happens on the screen. On the test car the option was not in the same place, and the co-pilot did not know and could not find a place to change either distance or speed.
3.
Tyre pressure display: The co-pilot did not know and could not find how to display the tyre pressures on the centre screen.
4.
Regeneration cut-out speed: In the Volt regen stops at 5 km/h. On the Model S, it was between 7 and 6 mph (see above) so, probably at 10 km/h.
5.
Rear visibility: The hatch window looks really small in the rear view mirror. The Volt’s is already small compared to the Prius, but the Model S is almost not worth the effort. I also found that the driver side mirror does not adjust far enough out to cover the 7 to 9 o’clock area.
6.
Brake override: See why (
Toyota Settles Over Death of Family in High-Speed Crash - NYTimes.com), and how (
About Toyota | Our News | Toyota Evaluates Unintended Acceleration Complaints in Remedied Vehicles). GM also (
GM to Expand Brake Override Software Globally by 2012). In order to simulate stopping the car with a stuck accelerator, my usual test procedure is to start by flooring the accelerator with my right foot, accelerate to 100 km/h and then apply the brakes firmly with my left foot while holding the accelerator down. Even in cars without brake override, the brakes are strong enough to bring the car to a controlled stop pretty quickly. The Model S failed this test in the most unexpected and unusual way. The test route didn’t have enough space to perform this at 100 km/h, so I started at about 70 km/h / 40 mph. The brakes prevented further acceleration, but did not slow the car. I was about to abort the test, when it slowly started to decelerate, so I kept going. This was probably due to better friction from the pads as they warmed up. Then, at somewhere between 30 and 20 mph, and 3 to 5 seconds after braking, the car suddenly came to a violent stop. This startled me and upset the co-pilot tremendously! It is entirely possible that I didn’t push the brakes hard enough, but there wasn’t enough space or time to try again and the co-pilot certainly wasn’t in the mood. However, I would then argue that the force required for maximum braking is too high, and that the abrupt stop at the end indicates that I did push hard enough. So, it appears that the brakes are not powerful enough, and if there is a motor power reduction, it takes far, far too long to trigger (should be < 0.5 s). Huge Fail. I’ve been encouraged to, and will try to get an explanation of this behaviour from HQ. (
Update: With Tesla Engineering as of Aug 1)
Untested
1.
Sun visor extension: I wanted to check that the sun visor swivel arm can extend so that the visor can reach the B-pillar, but fussing over the speed display distracted me and took too much time.
2.
Interior noise level: The intention was to measure A-weighted and C-weighted noise at 80 and 100 km/h, but the practice run revealed that there would be time for only one measurement. Unfortunately operator error resulted in no measurement taken. For reference, the Volt noise levels are: 59 dB-A and 81 dB-C at 80 km/h and 61 dB-A and 82 dB-C at 100 km/h on new asphalt. My perception was that the Model S is slightly quieter in the C-weighted range and significantly quieter in the A-weighted range. I suspect the air suspension has a lot to do with that.
3.
Cruise control increment in km/h: This test was not performed because we could not get the speed display in km/h. Pass would be if the cruise control increments in 1 km/h steps if the speed display is in km/h and fail would be if it increments in 1.6 km/h steps.
4.
Ease of parking: I am concerned about the width of the car when parking (particularly in narrow California parking spaces). Unfortunately all the spots on the approach to the staging area were taken.
Conclusion
I went to the drive expecting and hoping to be wowed, but was not. Maybe this is because the Volt is already so much better than most other cars that the Model S cannot be
that much better. Or maybe the Volt is just a better fit to my needs and expectations. The Model S is a much bigger car than I need for daily single occupant commuting. I will keep my reservation and re-evaluate when the time to configure comes in the hope that the failed items are corrected and the untested items pass. Other items that could affect my decision include adding creep, adding a poorly implemented hill hold, interior lighting changes, lack of front proximity sensors and collision avoidance.
As others have said, the Model S is simply too expensive a car to use for one, at most two hours a day and not meet all my expectations.
View attachment 8315
Graph 1: Model S Acceleration. Non-performance. Standard regen. 4 occupants.
View attachment 8316
Graph 2: Volt Acceleration. Normal mode, L regen. 2 occupants.
View attachment 8317
Graph 3: Volt Acceleration. Normal mode, L regen. 1 occupant.