"Driving normally" in a Tesla Roadster: by the numbers

[KarenRei]

I'm working on validation of my vehicle range simulator, and one of my drive testers owns a Tesla Roadster. We're not able to get data straight from the powertrain, but he has the camera film one of the displays and calls off numbers from some of the others, as well as what's going on around him. I'm then by hand writing out the numbers from some of the sections.

His instructions were to "drive normally" in as varied of conditions as he could. Well, for the most part, I'd say he did that. But occasionally, "normal" for a driver of a Tesla Roadster isn't exactly what the rest of us would call normal. Check out the following numbers I just ran into.


Time (seconds), Torque (Ft.Lbs), Horsepower, Acceleration (Gs), Amps, Speed (mph), Vocal comments

969.5 30 13 0.04 20 "I'm going to pass this truck in front of me"
971.3 30 13 0.04
971.9 59 29 0.04 <- Begins to press the pedal
972.5 111 58 0.15
972.8 165 96 0.31
973 221 149 0.52
973.4 226 174 0.51
973.9 230 195 0.52
974.2 237 231 0.59 <- Pedal is all the way down
974.6 227 240 0.54
974.9 209 241 0.5
975.5 194 241 0.55
975.9 191 249 0.43
976.4 179 248 0.4 645
976.6 168 244 0.47
977 159 241 0.34
977.5 154 242 0.32
977.7 143 235 0.4 <- Begins to release the pedal
978 132 223 0.28
978.5 118 206 0.34
978.7 110 196 0.31
979.1 95 173 0.2
979.4 28 50 0.11 80
980 -16 -29 -0.09 <- Pedal is released - overshot and now regenning.
980.4 -28 -51 -0.06
980.9 -28 -50 -0.11
981.4 -29 -50 -0.17
981.8 -30 -51 -0.12


I hope the driver of "that truck in front of him" didn't run off the road in the process ;)

Oh, and for those who care: The Roadster's onboard pack-monitoring computer runs Linux. ;)

[Ardie3301]

So, let me get this straight: The Tesla driver starts out doing 20 mph, then decides to pass a truck, and begins accelerating. 4 seconds later he's got it floored, and 5 seconds after that, he's doing 80 mph.
The roadster's torque ramps up to the neighborhood of 200 ft-lbs, and the controller is pulling upwards of of 650 amps to do it, cranking out nearly 250 horsepower.

So? That could be my wife "driving normally" in the Vons supermarket parking lot -- if it wasn't for those pesky speed bumps. :-)

-- Ardie

[KarenRei]

Your wife's car has ~250 horsepower over a wide range at a sub-3000lb weight? :) Also, it's about 2.3 seconds to push the pedal down, pedal down for 3.5 seconds, and pedal off in 1.9 seconds. I'm sure someone going for speed could get better times out of that machine, but still...

[zguitar71]

.59 G's during acceleration is pretty quick. I would love to drive one. I wish 3000 lbs was considered heavy but in today's word 4000 lbs is common, for a car!

[Aptera#1434]

My boss just bought a Tesla last week. We just went for a ride in it moments ago. :jumping0007: Man, it is quite exhilarating to drive. What a treat and a thrill it was to finally drive a spirited EV. 0-60 in under 4 seconds! It handles like a slot car. The fit and finish work is fantastic.

And the regen brake system is amazing. One hardly needs to touch the brakes until the last several feet before stopping.

[randyd]

And the regen brake system is amazing. One hardly needs to touch the brakes until the last several feet before stopping.

So, what does the driver have to do (exactly) to slow the car down at the desired rate (i.e. control the regen dynamically)?

[Aptera#1434]

So, what does the driver have to do (exactly) to slow the car down at the desired rate (i.e. control the regen dynamically)?

Well, I'm not an expert, but with normal driving in the Tesla, I didn't need to use the brake pedal in town until the last several feet before a stop sign or stop light.

The regen seems to be aggressive, but not to the point of annoying or feeling like it will send you hurling through the windshield. I didn't use any controller for regen other than that of the normal drive mode. I'm not sure if there is a manual override to the factory settings.

Slowing down felt like being in 1st gear at 25mph speed in an ICE engine car with manual trans and then removing your foot completely from the accelerator pedal to let the engine and transmission slow you down rapidly.

The Tesla doesn't use a transmission apparently.

[rayfellow]

This article about the Tesla was in the New Yorker Aug 24th.

http://www.newyorker.com/reporting/2009/08/24/090824fa_fact_friend

[Matthijs]

AY-EhnWzcg8
Link (http://www.youtube.com/watch?v=AY-EhnWzcg8)

[Dolphyn]

The regen seems to be aggressive, but not to the point of annoying or feeling like it will send you hurling through the windshield. I didn't use any controller for regen other than that of the normal drive mode. I'm not sure if there is a manual override to the factory settings.
I think it's adjustable. I talked to someone yesterday who said (from experience) that at the maximum setting it does feel like it could send you through the windshield.

[Aptera#1434]

I think it's adjustable. I talked to someone yesterday who said (from experience) that at the maximum setting it does feel like it could send you through the windshield.

Interesting. I'll ask my boss if his Tesla has the adjustable regen, or if it is an option.

A guy who had a 2007 Tesla, number 33 at the 8/29/09 Palo Alto/Stanford EV Rally didn't mention if his regen was adjustable.