Traffic sucks . . . but the mpg doesn't

[eastercat]

Ever since I got my Prius on 19 May, I haven't
gotten a chance to drive it on the highway.
Today, I finally got my opportunity.
First thing I did was to finally increase my
tires' pressure to 42f/40b. Because the gas
station I frequent only gives free air to customers,
I shelled out the the $1 (two $.50 cycles) to fill
my tires.
I got onto 635 from Garland Rd. and went west.
Considering it was 10 a.m. in the morning,
I was surprised by the amount of traffic going
west on 635. The traffic made it impossible to
go faster than 55-60 mph.
After passing the area where 635 and 75 meet,
I got an even ruder shock. Traffic was so clogged
that everyone had slowed to a 30 mph crawl.
I have to imagine that it was some sort of accident,
but I wasn't really caring. At some point, the traffic
stopped and I checked my mpg on the MFD.
I noticed that I was getting the little green cars
of regeneration on my display. Woo hoo!
I was finally able to get to my friend's house and
pick up my cat's food. Deciding that getting back
onto 635 would be an act of futility, I decided to
go from Royal/Midway to 75 and drive home from there.
Because the traffic on 75 was light, I was able to
decide what speed I wanted to drive. I decided to
go the speed limit (60 mph). While I did go a little
faster at times to pass slower cars, I made sure to
not exceed 65 mph. This drive was a decent mix
of city and highway and it gave an exemplary
performance.
During my entire drive, I got a minimum of at least
one green car of regeneration and reached a maximum
of two and a half. Obviously, not as impressive as the
hypermilers, but I'm damn happy.
My starting avg was 47. When I finished, my average
had increased to 49.5 mpg. Of course, my work
commute (7 miles) has brought the average down,
but knowing what's possible is really exciting.

In case I haven't said it before, I *love* this car.

With a big grin,
Esther

[DanMan32]

Actually, you want to avoid getting green cars, by avoiding braking when possible. Reason being, there are losses for the kinetic to electric to chemical conversions, and then the reverse when you use what you stored.

Think of it this way: you pour water from one glass to another, to another, then drink. You don't get all the water you start with, some sticks to the glasses. If you did this often enough, you'd have no water to drink.

Now one of course has to brake sometimes, and it is better to brake and store some of that energy as reusable battery power. That's better than nothing, but it isn't everything.

Supposedly it is the same situation with getting green (7 or 8) bars, but at least it makes the appearance of more efficiency as my MPG is quite a bit higher when I get past the upper bounds of 6 bars. However, that was probably at the expense of excess engine power earlier.

[bruceha_2000]

Congratulations on getting your Prius Ester. I know you have been waiting a while.

Dan is right, your GOAL isn't to get as many green leaf cars as possible. However, even when you are driving 'Prius style' and coasting (within reason) to signals, planning or hoping to hit them after they change green without annoying the people behind you that just don't get it, you will regen and sometimes get leaf-cars. You will also get them if you are coasting down hill if the grade is enough to maintain speed.

One thing I found helpful MPG wise was Dr. Evan's description of 'moderate acceleration': Fast enough to get arrows from the engine to the wheels and from the engine to the electric motor to the wheels. No arrows to or from the battery. I need concrete, measurable descriptions :-)
That way, all the gas that is burned is used to move the car NOW rather than incurring the losses going to and returning from the battery. Once you get to speed, the engine will happily charge the battery as all its power isn't needed to keep the car at speed unless you are going up hill.

You will notice that at highway speeds, even on gentle hils, the ICE still has more oomph than needed to keep the car going and will be charging the battery.

[DaveinOlyWA]

actually avoiding green cars is not possible in traffic since they can be generated by simply going up and down hills without braking. Coasting in drive will do it also.

if you make the trip without braking then that is where you want to be. keep in mind that keeping a larger than normal following distance in heavy traffic may piss off the person behind you, but it will only lengthen your trip by seconds