2012-06-23

After driving the car for a little bit

After driving our new car for a couple months, I am happy to report that I'm quite enjoying the experience. More than just resting safe in the knowledge that my car will start up in the morning (and every time I take my foot off the brake at a stop light), it's a pleasure to drive. I'll be honest, it's pretty likely that almost any new car would have been fun for me. I may have been used to the quirks of my old car, but it's nice to have a car where I don't have to know any quirks.

Our car is a 2012 Honda Insight. The Insight is a hybrid, more specifically it's a mild parallel hybrid. It's mild because the electric motor is used primarily to enable the idle-stop feature and as a little extra boost of power when accelerating quickly or driving up hills. What this all amounts to is that our car can't (or won't) operate in electric-only mode. I've decided that the main purpose of the electric motor in the Insight is simply to boost fuel efficiency by reducing the need for extra gas in higher performance situations like entering the highway or going uphill.

Here's a view of our instrumentation:


One of my favorite things about this car is that it's got a digital speedometer. It's so much quicker and more accurate to read than a needle.

On the right there's a fuel gauge, in the middle the tachometer and little computer display, and on the left we have a little meter to show us whether the car is using the electric motor, charging its battery, or neither. The little green leaf in the upper left corner indicates that the Econ mode is on. What that really means in relation to fuel economy I have no idea.

I'm not much of a car reviewer, so I'd really rather just describe the way I've altered my driving style in a small effort to increase my fuel efficiency without going to ridiculous extremes.

Speedometer efficiency indicator
Not sure what to call this. Behind the speedometer there's an arch of color that's supposed to indicate how efficiently you're accelerating or braking. It has three colors: green, teal, and blue. The greener it is, the more efficiently you're driving. You can see a little of it in the picture. But I question it sometimes. More on that below.

Efficiency indicator screen
I'm not sure what to call this one either. It's just a different view of the same information the speedometer version gives you. Instead of different colored lights, on the computer screen there's a horizontal bar and a progress-bar-like thing starts in the middle and moves further left or right depending on how efficiently you are braking or accelerating.

Electric motor assist gauge
When the car isn't using the electric motor, the needle points to the middle. When the car is using the electric motor to slow the car while charging the battery, the needle starts moving toward the green side. It can only capture so much energy though, so once the needle gets close to the bottom of the gauge the speedometer efficiency indicator turns blue. If you're accelerating quickly or the engine needs a little extra boost to keep from wasting too much gas, the needle starts moving up into the blue to indicate "how much" it's using the electric motor. The efficiency indicator turns more blue the more electric motor you use.

This needle and progress bar are besties.
Instantaneous fuel efficiency
One of the modes on the computer is an instantaneous fuel efficiency screen that shows a progress-bar-style display of your current mpg, and also shows a numeric value indicating your trip-average mpg. There are two trips, A and B, and we have A set to reset at every fill-up. We use the trip average as part of the data we keep to track how we're doing and we'll use the B trip to watch the average over a road trip if we ever get to go on one.

Coasting gives impressive mileage.
Session-average mpg
The screen after the instantaneous efficiency screen is one that shows your average mpg for the current session (since you turned the engine on), and the previous three sessions. You can see it in the image at the top; I was excited to see that on my way home from Walmart last night I got around 57 mpg. It makes driving a game: try to beat your previous score without pissing off the cars behind you!

How I use it all
I've decided that the color-shifting and equivalent computer display of the acceleration/braking efficiency is relatively useless. My reasoning is that there are times where it's valid to give the car a bit more gas. The car will judge you for it, but there's nothing you can do about that, so it's not worth worrying about. In fact, that's one of my tactics these days.

Give it gas
I read somewhere that one way to increase fuel efficiency is to speed up as quickly as possible. I'm not suggesting peeling out by any means, just smooth but strong acceleration. On a normal transmission the idea is to get you into more efficient gears quicker. Lower gears, if I've understood things, are good for getting started but horrible for distance On the CVT with the electric assist motor, my feeling is that it makes the most real use of the electric motor. Under what the car feels is efficient acceleration, you barely use the electric motor at all. Plus, it takes forever to get up to speed. Basically, the sooner you get to the speed limit, the sooner you can coast some.

Coast
Whenever possible, coast. Apparently, many engine control modules will cut the gas if you're coasting, and allow the motion of the car to continue driving the engine. This is born out in my experience in coasting situations where, like in the image above, the car will indicate "100" mpg. If there's no injection it's more like  ∞ mpg. Really helps your average.

Speed on your way down hills
Within reason, of course. Don't be too concerned if your speed drifts a few above the limit on your way down a hill. If it's a gentle hill you may even help it out a little by giving it a little gas. I say a little because if you have a light enough foot, the car won't actually give you gas but will just lay off on the battery charging and let you coast a little more freely. The idea here is that if you pick up a few mph on your way down a hill, there's a little less work the car has to do on the way up the next hill.

Brake sooner
If you know you'll definitely have to stop, slow down as slowly as possible. Given no cars behind you, this would preferably be done mostly by coasting. But if you've got to use the brakes, the idea is to use them as little as possible. In fact, though it's hard for me to tell for sure, I think our car will avoid applying the brakes even as we push the pedal if we're not pushing too hard. Instead, it allows the weight of the car to turn the engine and in turn the electric motor to charge its battery, slowing the car a bit more than when coasting and reclaiming some energy in the process.

Idle-stop as soon as possible
While slowing slowly is good, it's also good for the engine to be off. The auto-stop feature engages if you were moving at a speed greater than 7 mph and then slow down using the brakes to under 7 mph. Also, once you slow to 10 mph or so while coasting, your instantaneous efficiency starts to drop as the engine starts using fuel to maintain its idle speed. When the car auto-stops, it turns off the engine and leaves you in a peaceful silence at stop lights. Don't worry though; it'll use its battery pack to start the gas engine when you take your foot off the brake. Or if you sit there too long it'll think you are getting too hot, so it'll start back up to keep you cool.

Keep an eye on your gauges
I ignore the green/blue thing. But I watch the needle on the left and I usually keep an eye on the instantaneous view. Lately I've also been watching the previous-sessions screen a little to try to get a better idea of what driving behaviors affect each trip.

So we're happy with it
Like I said, any car newer than our old ones would have been wonderful. But with this one we feel like we're doing what we can to save on gas. We're also down to just the one car. That's going pretty well too, with the occasional day where Jess has to take me to work. After a few more tanks, we'll give you an update on how we're doing efficiency-wise. So far our average based on gallons pumped and distance driven is about 42 mpg.