About the Site

How does the site work?

The site interfaces with Onstar's Partner API to poll vehicle data from cars. Currently, the service is polled 2 times a day for updated vehicle information. The synchronization runs start at 10 AM/PM central time.

What happened to data like last trip info, tire pressure and oil life that we used to have?

When we switched over to the new API, OnStar only gave me access to the following data points: Total miles driven, EV miles driven, and total gallons of gas burned. If you'd like access to the rest of the data restored, please let OnStar know in a polite email to your Volt Advisor.

It'd be cool to track X, can we do that?

Maybe, if I can figure out X from the data points we have. If you'd like to see more data points (such as kw-hrs used), please let OnStar know in a polite email to your Volt Advisor.

Why doesn't my MPG match what my car/Remotelink/myvolt.com says?

We are no longer getting the MPG reported by the car from OnStar, we're getting Total Miles and Gallons Burned, and from that we can calculate MPG. This MPG number could possibly be different than the MPG your car reports. We're not sure what causes the discrepancy in the reported MPG and the reported gallons burned, but gallons burned is more than likely the correct number if they conflict. Before the switch to the new API we were only getting reported MPG, and MPG/Total Miles didn't result in a consistent gallons burned, which was always a little fishy. That used to beg the question...

DEPRECATED: Why do the MPGcs numbers look wrong/weird?

Short answer: I don't know.

Long answer: I don't get a reading for gallons of gas burned through the webservice, so I have to calculate it from MPG and total miles driven. For some reason, the numbers seem off for new cars or cars that aren't driven much on gas. The only reason I can think of why this is happening is that when the odometer is set to 0 the entire Volt computer isn't reset, so there are some "phantom gallons" from QA testing in the Volt's computer that affect the MPGCS.

Updated answer: We're now getting gallons burned directly from OnStar, so hopefully all will be well now!

Security

Do you store my OnStar credentials in your database?

No, Volt Stats only stores a token in its database that it receives back from the OnStar API OAuth service, which can be used to communicate with your car. The token can only be used for reading data from the car, it does not have permission to perform any actions on the car.

Can you see the current location of my car?

The amount of data that Volt Stats can pull from OnStar is restricted. Volt Stats does not receive, and has never received, any sensitive information about your vehicle or OnStar account such as car location or credit card numbers.

Do you hash my password?

Yes, Volt Stats hashes and salts your password using bcrypt.

Source Code

What is the site written in?

The site is written in ASP.NET MVC 3. It used be hosted on Apache through mod_mono, but I ran into a lot of stability issues that had me questioning my sanity. Needless to say, it's now running on IIS.

What happened to the source code?

Unfortunately, the source code is now private with no hope of being opened up per the terms of our partnership with OnStar.