Maintenance

[Takumi]

The Tesla Roadster’s specs illustrate what it does (0 to 60 in about 4 seconds) — as well as what it doesn’t (zero emissions, zero motor oil). With one moving part in the motor, no clutch, and two gears, it’s not only a joy to drive, but to own as well. There is no motor oil to change; no filters, belts, or spark plugs to replace; no oxygen sensors to mistrust before an emissions test — in fact, no emissions test required ever. Other than inspection, the only service we recommend for the first 100,000 miles is brake and tire service.

Interesting, as the site also mentions:

"...you can soar along at top speed, knowing the only oil in the car is in the transmission, the only emissions are the songs from the radio, the ride becomes more enjoyable still."

What other maintenance will this car possibly have and what other maintenance will this car be lacking compared to the conventional vehicles?

[tonybelding]

Brake pads eventually need to be replaced, but they should last a long time due to the use of regenerative braking.* The main "consumable" cost of operating the car should be tires.

The battery pack is rated for 100,000 miles.* In fact Tesla estimated it should last 125,000 but decided to be cautious and officially call it 100,000.* At that point the capacity has degraded to 80% -- you could continue driving it if you can live with the reduced range and power.* It does seem likely that the battery technology should be improved by that time, so you'll have more incentive to replace it.*

The electric motor has ceramic bearings that are rated for 100,000 miles.* I assume it should be possible to get those bearings replaced instead of having to replace the whole motor.

The biggest mechanical worry I have is the transmission.* It looks like it's unique -- who designed it, where did it come from?* Will it be durable over the long run and survive all the stresses that high-torque motor puts on it?* I had a little qualm when I was reading the recent "test drive" report in Popular Mechanics, they said the car was locked in 2nd gear because it was an engineering prototype and wasn't ready to withstand being shifted!* Let's hope they get that sorted properly, eh?

After 100K miles you go into longer-term thinking, and your main concern would be things like. . .* wear and tear on the steering and suspension. . .* *wear and tear on cabin switches and upholstry. . .* *gas struts need refurbishing at some point. . . And stone chips in the paint job, don't forget!* (It hasn't been mentioned, but the car really should come with some protective film like Lotus's "Star Shield", which is optional on the Elise.* Practically everyone who got an Elise without Star Shield soon wish they had it.)

The fascinating thing about all this from my standpoint is, we're talking about an exotic sports car here -- and the maintenance costs on exotic sports cars are usually murder.* I've already had this experience with my Lotus Esprit V8, which falls in exactly the same price category as the Tesla Roadster.* "You're charging me how much for an oil change?"* Squinting at the service bill. . .* *"Are these some new kind of spark plugs made from gold?"* I've heard Ferrari owners have it much worse, even.

If you plan to keep the car a long time and drive it a lot (and who wouldn't?), and if we assume gasoline prices only go up from here (as seems all too likely), you could easily save $30,000 and a lot of hassles over the life span of the car compared with conventional high-performance sports car.* It makes the Roadster actually look like a bargain next to most of them.

[doug]

The biggest mechanical worry I have is the transmission.* It looks like it's unique -- who designed it, where did it come from?* Will it be durable over the long run and survive all the stresses that high-torque motor puts on it?* I had a little qualm when I was reading the recent "test drive" report in Popular Mechanics, they said the car was locked in 2nd gear because it was an engineering prototype and wasn't ready to withstand being shifted!* Let's hope they get that sorted properly, eh?

The impression I got was that the car was locked into 2nd gear so that the test driver didn't go nuts with the accelleration.* I expect at some point the transmission fluid needs to be changed.* Wonder what the interval on that is.

[doug]

Actually it looks like the transmission was having problems. In this Today show test drive video it actually broke!!
http://video.msn.com/v/us/v.htm?g=98...9C7&f=&fg=copy
It's pretty cool though, because you get to see a few shots of inside the drive train.

[Takumi]

In that video, Martin values that prototype at $300,000. Wow that's a lot lower than most which are usually around the millions... and is it me or is that prototype giving a lot of pre-launch drives? If the prototypes are this robust already...

[tonybelding]

The Tesla Roadster was developed very cheaply in comparison with most cars made by GM, Ford, Toyota, Honda, etc. Basing it on the existing Lotus Elise was a brilliant move. The other thing to remember is that big car companies won't introduce a new model unless they feel they can sell 100,000 of them, so they can afford to spend a lot on development. It's a completely different scale of business.

Did you see the videos where Tesla are testing the Roadster on a frozen lake? That was wild! I never get tired of watching them, especially that second video. I gather they have also been showing off to reporters with blasts of acceleration up the freeway on-ramps, and leaving local ricers in the dust. 8)

Somebody at the Lotus factory commented on his surprise that the prototypes would run when they come off the assembly line, no tinkering needed. I don't know if that's interesting because of what it says about the Tesla Roadster, or because of what it says about Lotus's regular production cars.

[Michael]

Brake pads eventually need to be replaced, but they should last a long time due to the use of regenerative braking.

I understand that there actually is no brake assisted regenerative braking; it's only regenerative braking from the standpoint of the electric motor itself acting in a similar manner to an ICE engine that's running at lower RPM's and creating a drag at the wheel. Since there is no additional regeneration that occurs as a result of pressing on the brake pedal, I wouldn't expect that brake pads would last any longer than any typical ICE vehicle.

[WarpedOne]

Michael, you are right and not completly right at the same time

Tesla Roadster's regenerative braking is not operated via brake pedal. Braking subsistem is classical with ABS.

Regenarative braking is applied when you depress the accelerator and the car starts to move faster than the motor would provide. But this is not "automatic". If you take Tesla's motor and turn it by hand, it won't generate any electricity. To operate is as a generator (as is done in generative braking mode) control electronics has to apply some parameters to put it into "generator mode". So I figure, regenerative braking kicks in when you depress the accelerator "enough", when you depress it just a little the car will just coast along.

I am not an EE so I won't pretend to know exactly what I am talking about. I just remember reading this somewhere and I cannot find the link >

[tonybelding]

I understand that there actually is no brake assisted regenerative braking; it's only regenerative braking from the standpoint of the electric motor itself acting in a similar manner to an ICE engine that's running at lower RPM's and creating a drag at the wheel. Since there is no additional regeneration that occurs as a result of pressing on the brake pedal, I wouldn't expect that brake pads would last any longer than any typical ICE vehicle.

The point is that you won't have to press on the brake pedal as often. Part of the time you will be using regen instead of the brakes to slow the car. Therefore the brakes will last longer.

I suppose one could argue that regen is only taking the place of engine braking on a conventional sports car. But engine braking with an internal combustion engine is not encouraged, it serves no useful purpose. Honestly, I'd much rather put wear and tear on my brakes than on the car's engine. With the Tesla it's different: using the regen is encouraged because it doesn't put any wear or stress on the motor and it recovers useful energy.

I think WarpedOne is right, the electric motor can be "programmed" to develop different amounts of regen by controlling the amount and phase of current that is inducted into the rotor. Or something like that.

[vfx]

"I think WarpedOne is right, the electric motor can be "programmed" to develop different amounts of regen by controlling the amount and phase of current that is inducted into the rotor."

The Ebox Prototype has a sliding lever on the dash. One end of the slider gives no perceptible regenerative braking so when you release the accelerator pedal the car just coasts to a stop.
At the other end of the slide it's the opposite.

When you release the pedal the car comes to a VERY quick smooth stop. With some practice, you would almost not ever need to use your brakes. Of course you can set up the regen braking slider at anything in between these extremes.


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