New Camber Arms

I bought a full new set of tires per the recommendation of my local mechanic, Ron Raimes automotive.  The tires were again wearing heavily on the inside sidewalls in an unusual pattern as you can see in the picture below.  The standard inside wear markers were not yet worn down.  These set of tires are not nearly as bad as the last set, but they still did not wear very evenly.fourtires

When he looked at the alignment before installing the new tires, the alignment for both the toe and the camber were again out of spec.  My mechanic suggested that he would install the tires, align them and then suggested I come back again in 1,000 miles to see if the tires would stay aligned.

Since Tesla had been quite responsive when I had alignment issues in the past after emailing them at the VP level, I decided to send them a note discussing this current state of alignment.  Only 7,000 miles had passed since the Minneapolis center had adjusted my alignment again, so I was a bit concerned.

I took my car to the Sunnyvale service center and explained the entire saga.  I had only driven my car 200 miles with these new tires.  When they checked my alignment, the tires were again out of alignment. The alignment had shifted in those 200 miles but the vehicle measurements clearly show that the camber is out of alignment.  A tire shop has no ability to adjust the camber.  The camber in the rear was at -2.3 and -2.32 with the spec being between -1.4 to -2.1.

Because I had expected to wait at the service center, I did not bring my house key or garage door opener, and the car was driven 30 miles between the first 6/26 check by Tesla and the second set of numbers the next day when they did the alignment.  I am a bit concerned about the amount of variability in the shift of the front toe.  The front left shifted from -0.16 to -0.27 in 30 miles and the front right shifted from 0.07 to 0.31.  I have included five sets of alignment data in the table below over the course of 250 miles.  I am a little concerned that the alignment does not appear particularly stable although these numbers are quite small.

June Alignment Data

June Alignment Data

Alignment Using Laser Interferometers

Alignment Using Laser Interferometers

In both shops, I watched the alignment process.  They use the same brand alignment machine, Hunter, which uses lasers to accurately check the alignment.  As an odd side note, my summer job between junior and senior years of college was working with laser interferometers at Hewlett Packard, so I know these machines are very accurate.

My local garage did complain that the rear tires are physically difficult to align.  The configuration of the car makes it quite difficult to get the mechanic’s arms in the correct place to adjust the alignment.

Sunnyvale Tesla in the end concluded the problem with my alignment was the camber bushings, which is the rubber part in the camber arm. They replaced both camber link arms with a newer upgraded version.

The new camber arms also have an improved design and a more complex shape that should support more torque than the original camber arms.  I am hoping the challenges with alignment are completely solved, but I will have it check again by both my local mechanic and Tesla to ensure I can drive many miles with these new tires.

Original Camber Arms

Original Camber Arms

Location of Camber Arms in Wheel Well

Location of Camber Arms in Wheel Well

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Warm Supercharging

Traveling in warm climates using the superchargers is a breeze.  For the last week I have barely had to give charging much thought.  The superchargers are generally placed reasonably close and the warm weather and almost flat roads result in a low kWh/mile and more range.  I was a bit surprised that throughout the south I am still encountering a number of potholes and rough roads but my tires still seem fine.

Slave Quarters Behind the Main House in Charleston, SC

Slave Quarters Behind the Main House in Charleston, SC

No matter how many times I visit the south, I am always reminded how nice southerners are.  They take the time to genuinely greet you.  I also had random people help me get in and out of a slightly broken hammock only seconds into my mild struggles.

The last supercharger I visited in Macon, Georgia is not yet on the Tesla supercharger map.  Other Tesla owners reported charging there less than a week ago on the forums.  I did have a backup plan of a public charger nearby in case access was disrupted for construction reasons, but I had no problem charging as a construction worker was nailing boards around the transformers.

Equal with caring for the environment, I am also a strong supporter of treating all humans on the earth equally and with dignity and respect.  So I have visited many museums and sights related to the struggles in the south including the Martin Luther King King National Historic Site in Atlanta, the Harriet Tubman Museum near the supercharger in Macon, and the slave quarters in the Aiken-Rhett house in Charleston.

In Greensboro, North Carolina, I also went to the International Civil Rights Center and Museum.  During the tour, you see the original lunch counter where the Grensboro four ignited the momentum that lead to desegregation of many public places.

Woolworth in Greensboro NC

Woolworth in Greensboro – Lunch Counter Civil Rights Protests Gained Momentum Here

Close to the Limits

We finally had a rainy spell this winter during our drought here in California.  One morning the car actually slipped pretty severely!  The road situation was actually very extreme.  I was driving on a very unusual pavement where half the roadway was a large grate — probably five feet in length.  So two of my wheels were on wet slick pavement and the other two were traversing this highly unusual grate.  For a brief instant the car definitely swerved and scared me a bit but the quickly corrected itself as nothing had happened.  I rarely actually take this particular section of road, but I vaguely remember it being dicey in the past.  I suspect this unusual grate was installed to correct severe flooding problems.

Limited Regen

Limited Regen

Late last year we had a serious cold snap and the garage one morning was around 40 degrees Fahrenheit (about 5 degrees Celsius).  To my surprise, I actually had a dashed yellow line — limiting regen.  While parked the car uses as little energy as possible to keep the battery warm in order to avoid the energy wasting vampire drain.  In cold weather you can drive your car with a cold battery, but the regeneration of energy into the battery is limited.  After only a couple of miles of driving, the battery warmed up and the yellow line disappeared.

 

Limited Acceleration

Limited Acceleration

As I earlier reported, I did a number of supercharger tests where I drained my battery down to 0 rated range.  While intentionally draining the battery, the upper limit of power was reduced — indicated by the dashed yellow line.  I don’t remember the exact rated range left before the power was limited but it was at a significantly lower level than normal.  The car still had enough pep to very comfortably drive.

I also noticed in the rain serious impact to the rear facing camera.  I think this is a problem with all cars.  I had grown a little too dependent on the camera during driving instead of the traditional mirrors and head turning.

Mediocre Visibility in Rear View Camera in the Rain

Mediocre Visibility in Rear View Camera in the Rain

19″ vs. 21″ Wheels

I have been waffling for the last few days about the wheel selection.  I was trying so hard to be environmentally and fiscally correct, but in the end I gave in after running some numbers and getting some more information.  Here are my reasons:

1.  The 21″ wheels are aesthetically pleasing.  Both the wheels themselves and the way they work with the entire car.

Aesthetically Pleasing Wheels

Aesthetically Pleasing Wheels

2.  Tires are actually repurposed when you recycle them!  80% of the recycled tires are used for other purposes.  Many recycled items such as plastic do not have a large market and 80% actually end up in the landfill.  The reverse case exists for tires.  Many are used for fuel and construction products or retreaded.  The EPA has a detailed breakdown for 2003 here.

3.  I live in the San Francisco Bay Area where we might get some frost less than 10 days a year, so tires that can seriously handle the cold are not important.  I also have a 4WD highlander for visiting the mountains.

4.  According to my Tesla representative, the Model S tire wear should mimic the Roadster for the 21″ wheel.  So in the worst case, my maintenance costs will not go up.

5.  Also, the 19″ tire will only last 50% longer than the 21″ tire.  I was expecting a very durable tire.  With regenerative braking, tires just wear out faster because of the backwards pressure on the tire.

6.  The Model S also has a low mode of regenerative braking.  This low mode slows down the feature and is very useful while driving uphill on curvy roads.  Saves the momentum for the next hill but also saves wear and tear on the tires.  The Roadster did not have this option.

7.  I do live close to some lovely mountain roads with some very fun driving and hiking trails.  Unfortunately they are a bit too busy to justify a performance Model S, but they help justify 21″ wheels.

8. One Roadster owner on the Tesla Motors Club forum reported his Model S tires are wearing much better than his Roadster.

9.  Some people are worried about 21″ tires with potholes.  If I drove often where there was a lot of potholes, I would consider the replacement costs for the rims.  Fortunately, I don’t encounter potholes very frequently.

10.  This decision has been haunting me for days.  I know I would be happy with the 19″ but I really like the 21″ wheels.  I’ve never really taken a fondness to a set of wheels before.

11. I also did a spreadsheet based upon my Roadster tire wear and tear.  I replaced my rear tires at 12K and 23K, and the front tires at 21.5K.  I think these numbers are higher than average, but I can access a freeway without going through any stop lights.  For this same condition, here is the overall breakdown of costs over a 15 year ownership period.  I found the exact same tires on some third party sites.  The following spreadsheet is just an estimate based upon my driving habits, and predicting the wear on the different sized tires.  Your mileage will inevitably differ than this estimate.

Long Term Tire Costs

Long Term Tire Costs