Wh/mi

Just by knowing how much energy we're using, my husband and I have become more interested in how we can be better consumers of energy.    Our Tesla Model S has the standard miles per hour dial on the dash, but the remainder of the information is different than what you find on most other cars.    Here's a picture of our dash, taken today as I was coasting safely down a hill with no traffic, on a straightaway, going a safe thirteen miles-per-hour.

The speed is shown in traditional fashion, on the left half of the dial.  It's also in easy to read numerical digits in the middle of the dial, so I look at that usually, checking to see if I've forgotten to go the speed limit again.   It's the right side the dial that I look at the most though, because that shows energy consumption.   If it's above the center line, I'm consuming energy (or kW) but if I'm coasting down a hill or slowing down via regenerative braking, its below the center line, showing how much kWs it's recharging the batteries.

The graph on the right shows the amount of Wh/mi used.   I live in a hilly area.   The graph shows the last thirty miles and it's mostly climbing up to drive on one of the roads around us with the word "ridge" in the name for good reason.   Then it's downhill to the main intersection with the mall that happens to have "valley" in it's name for equally good reason.  

Over on the left top are numbers that reset every time we leave the garage after unplugging the car (or unplugging from any charging location for that matter.)  It shows that today I went 21.2 miles, mostly to the dentist where he did loud and grindy things to my teeth for several hours.

The right-most number at the top is the one my husband and I talk about the most.  It's the average watts per mile (Wh/mi) for that particular trip.    We're comparing it with the numbers below, which show two trip distances.   the first is our lifetime Wh/mi which is 318.    The one below is reset from time to time to give us a more weather-specific sampling.

For example, in the heat of summer it is uncomfortable to go without air-conditioning, which eats up lots of lots of energy.   Then, you get into fall and you don't need any sort of temperature control for the car at all.  Suddenly, your Wh/mi numbers are coming in lower than ever.  You think you're some sort of amazing driver, but you're not...it's just nice outside.

Right now we're dealing with another issue: cold.   Using the heat for the car is a fairly heavy consumer of energy.   However, using the seat warmer uses less energy if you're in a heated (or un-heated) battle with your spouse over who drives more efficiently.    Something you can't control though is battery warmth and cold weather.   When it's very cold, even if you're willing to suffer through it with gloves and a hat, your car's batteries need to be warmed.    The car uses additional energy during colder times and even limits the amount of energy the brakes can place back into the batteries until they're sufficiently warm.

It's a fun competition my husband and I have going on though.  One of us will walk in saying, "I just got 272!"   The other one usually says, "what?" because having an electric car is still new, even after six months.   Then, after realizing the conversation is about Wh/mi numbers the other one will say, "how in the world did you get it that low?   Impressive."

The Big Boy Update:  My son and I were talking about how when I was pregnant with him, he was in my tummy.   He told me, "I saw all the food in your tummy when you were pregnant with me but some of it was yucky so I didn't eat it."

The Tiny Girl Chronicles:  Orange juice wasn't popular, or even liked in our household for a long time.   Then sometime back in the summer, Mimi gave some to my son.   Since that time it has increased in popularity so much that it's one of the top requests by my daughter for her beverage for most meals.