50+ MPG -- A Newbie's Quest

There are currently a number of active threads wherein new/prospective owners are asking what they should know to maximize the MPG potential of their Prius. As a three-month owner, still-a-Newbie, I thought I'd relate what I've done that has lead to my daily MPG rising from 42.7 to 54.7, a 28% increase.

The first time I drove my 2008 Touring, "Amapola." was when I picked her up in Rhode Island and drove home to Ballamer, about 450 mi, at 42.7 MPG. (That story was told in: http://priuschat.com/forums/newbie-...ulous-personal-prius-purchasing-qdyssey.htmlL)

Since then, I studied all the various techniques for maximizing MPG here on PriusChat. These are best summarized in: http://priuschat.com/forums/knowled...rating-mode-availability-reference-aid-2.html

This document is about as densely packed with info as can be. For a Newbie, it is nearly incomprehensible. Fortunately its builder, ksstatdead, includes cites for the threads from which the info was extracted. That is where the real high MPG information gold mine lies. That is where I learned how to do what was needed to get my MPGs up.

As prep for my assault on 50+ MPG, I pumped my tires up to 40/38 psi, and blocked my grill with foam pipe insulation. Because I have come to the opinion that the Energy screen on the Multi-Function Display (MFD) is not a useful real-time tool for pursuing high MPG, I bought a ScanGauge II.
(See http://priuschat.com/forums/fuel-economy/42280-mfd-energy-graph-mpg-h-better-way.html)

I found that once I learned the methods, I needed a daily MPG goal that was reachable, but not easy to achieve. As a default, I set 50 MPG as a daily goal for my 28 mi. round-trip commute -- the route is equally split between urban secondary roads and 60 MPH-average highway. Slowly over the following months, reaching that goal daily became somewhat frequent.

I noted that the greatest variation in the conditions of my daily commute was the temperature. I came up with this formula for my daily MPG target that requires me to really work to meet:
Great Daily MPG = Temperature + 1/2 (60 - Temperature) -- Temps in deg F
So, my target GDMPG for a 46 deg day would be:
46 + 1/2( 60-46) = 46 + 1/2(14) = 46 + 7 = 53 MPG
This has turned out to be a daily challenge -- I'm confident it will be valid up to 60 deg F. For higher temps, I suspect that 60 MPG will still be a challenging daily goal.

In the last two days, only two days short of three months of ownership, I made a 436 mi. round trip, Ballamer to Brooklyn, NY and return. This would be over the same route as that first trip and I could compare the resulting MPG with that first, rank tyro result. (I chose not to use the cruise control so that my understanding of the MPG skills would be put to the test.)

Some base line data:
MPG out - 53.9, MPG back - 55.5, Average MPG - 54.7
Temps both ways - 34 - 46 deg F. Dry roads. Winds minimal both ways.
Speeds typically 60 - 65 MPH

On this trip I pulled out all the stops, I used every trick I had been practicing on my short daily commute; Pulse and Glide, Warp Stealth, Super Highway Mode (SHM), and even engine off - gliding in neutral (NICE-off) -- exclusively on the steeper grades coming off the major bridges; Verazanno, Outer Bridge Crossing, Delaware River; and descent to the Susquehanna River Bridge.

I travelled mostly in the right lane. When 18 wheelers slid into my lane in front of me, I took advantage of "opportunistic" drafting. But I didn't chase them, and within a mile or two they pulled away. (Traffic was relatively sedate; most drivers, including the truckers, right at 65 MPH-- of the two clear exceptions, one was shortly pulled over by the NJ State Police.)

Right now, I'm at 3655 total miles and overall, "Lifetime," 47.2 MPG. I think that I'm learning the high MPG methods and how to use them in dynamic, real-time, on-the-road situations. As the temps rise in the next months, I'm looking forward to chasing, and even catching, 60 MPG at 60 MPH at 60 deg F -- 60-60-60.

I'm confident that with study and application you too can go beyond 50+ MPG.

God bless, and first, last, and always be safe.
"God helps those who first help themselves."

Newbie Power!
(Even the salt-encrusted Old Guard were Newbies, once upon a time.)

 

I Posted the following in a different thread I think it has some relevance here as well:

Here is a little game I created to help me internalize the right go-pedal
movement to get no yellow arrows to or from the HV battery. It may help
others too.

I noticed that even under even, steady acceleration sometimes the yellow
arrows went into the battery. Then moments later, they switched to going
the other way. Nowhere had I read what I was supposed to do to get no
arrows. Many posts talked about the no-arrow state, but none I had read
told how to achieve it.

So, I fiddled with very small go-pedal inputs. I found that when the arrow
was pointing up, into the battery, more go-pedal made it go away. When the
arrow pointed down and to the left, out of the battery, letting up on the
go-pedal made it go away.

So what's the game? To make the needed correction I needed to react
instinctively, instantaneously, without thinking. So the game is the arrow is
a snake, let's say a king cobra. When the cobra rears up threateningly, you
step --very, very gently of course -- on its head and he disappears. If the
cobra is slinking away off to the left, you hasten his departure by easing up
on the go-pedal. Kind of childish, but it worked for me.

For me the game was just an intermediate stage. I soon learned to instantly
take the right go-pedal response for up or down arrows without consciously
dealing with the "snake."

One caution, sometimes the display goes into an indeterminate state for a
few seconds with the arrows, snakes, rapidly alternating up and down. Just
hold the go-pedal steady and in a few seconds it settles to up, down,
or none. Then react as appropriate.

 

Make no mistake about it, when you're driving a car, any car, your main job is safety. The whole super-max high FE/MPH thing is a game, and just a game. It should never compromise safety. That said, there are times and places where the game can be played safely.

It can be difficult to discuss getting good FE/MPG because the readers are at such widely separated levels of experience, competance, comfort, etc. Hey, I'm just a newbie too, it says so in the thread title.

Soooo, there is not complete agreement on whether of not striving mightily not to charge the HV battery is a worthwhile goal. The Hobbit says not, and that's an opinion that can't be ignored. However, others feel strongly that due to conversion losses, any energy intentionally put into the battery is gas wasted.

Left to its own devices the CPU will keep the HV battery at 6 bars. It sneaks energy into the battery whether you like it or not. Sometimes it will run the ICE and charge the battery and not show any arrows.

The glory of the HSD energy management system is that its rules have some flexibility built in, it seems to be "fuzzy logic" based, which deals with ranges and multi-dimensional preferred conditions as opposed to specific numerical values. The good part of this is it means the driver can do things to push certain values or conditions to the extreme of a range.

SOC (State of Charge of the HV battery ) can be fiddled with within ranges set by the CPU. This is good because the driver, by knowing the route (topography, traffic, signals, etc.), can use the energy in the HV battery to minimize gas use. An example: it would be wise to use a little HV power to crest a hill if you know there's a long downhill on the other side.

Should the driver be staring at the MFD or ScanGauge? No, never, no more than he should be staring at the radio or the babe in the Jaguar over there. Quickly getting, evaluating, and using the info to take advantage of the HSD's built-n flexibility is an acquired skill. The Snake Game s just a way that might help some folks get up and over one of the learning curves a little faster.

Oh yeah, by inverting the Snake Game you can chose to put energy into the battery or take it out, when upcoming road conditions call for it. Cool.

Good luck... Be safe... Chill...

 

An often overlooked element of a comprehensive max-FE/MPG strategy is
route selection. This point was brought home to me forcefully last week.
I had a default morning commute route that predated the Prius, and was
based mostly on free-flowing traffic patterns. When I got the Prius I just did
the same old thing. What the heck, how important could it be?

In my initial pursuit of the illusive plus-max MPGs, I first focused on learning
and implementing the technical details of the many high FE/MPG processes.
But last weekend I had a minor epiphany of sorts. It was the realization that
chosing to go up hills when not necessary could be a good thing.

There are good hills and bad hills. A good hill has a short, steep rise, and a
long, gradual descent. In thinking about my carried-over daily route, I saw
that I was not taking advantage of two very good hills that were on roads
parallel to my route. The good thing was that using those hills would not
make the trip any longer nor add appreciable time.

Last Monday, I implemented a "new, improved" route. In the first instance
by climbing a smallish hill, I was then on a 1-1/2 mile "no arrows," 99.9
MPG descent that had the additional benefit of injecting me into freeway
traffic going downhill at speed vs. having to accelerate uphill on the old
route. In the second instance, as I exited the freeway I again chose to climb
a small hill as opposed to the former flat route. Again, this accessed a long
stretch of "No arrow" gliding that had the additional benefits of having
significantly less traffic, and once in the traffic signal timing cycle, I could
hit 6 or 8 consecutive green lights. Roll on!

So, what was the outcome? Before the route change, I was happy to arrive
at the parking garage showing 55-58 MPG. After the route changes, I rolled
into my spot at 66 MPG. Of five AM commutes last week, I hit 66 MPG twice
and 61-64 the other three days. This is really sick. I'm lovin' it! (Security,
lunatic prancing about and halooing in section 2A. Code 3; soft restraints
indicated.)

I'm thinking that the title of this thread might now read;
"60+ MPG --- A Newbie's Dream."

So, take a hard look at your routing. Changing it, even ever so slightly to
use "good hills," could make a big FE/MPG difference.

 

I posted this on another thread, but it fits here as well ...

Yesterday, I had a new owner's wake up call. Temp was 100 deg F,
humidity above 90%. (I've read that humid air is less dense than dry air. It
sure didn't feel like it though.) Had parked the car in the open, it was hot
as an oven, even though I have the front/back window sun deflectors, and
cracked the windows.

I got 57 MPG over the 7.7 mi. trip to work. In that distance I drop down
some 350 ft. in altitude. On a good day --light traffic and some luck with
traffic lights -- I can get home at 5 MPG less that the outbound trip, in this
case 52 MPG. BTW, this is all city driving.

When I started the car, I remembered that I'd read that the HV battery
works best at temps we humans like; warm in the winter, cool in the
summer heat. So I set the A/C at 78 deg., Auto, and expected a MPG hit.

But, Oh! What a hit! Got home at 44 MPG.

For most of the trip the A/C fan was running halfway between Med and High.
At stop lights, the ScanGauge said the ICE was stopped, yet there was
mechanical noise from up front, which I take to be the A/C compressor.
Most of the way the H/V battery gauge was at 4 bars, occasionally 5, when I
usually see 6 pretty much all the time.

So, it looks like I'll have to get used to a new-for-me hot weather reality.
MPGs in the mid 40s as opposed to mid/upper 50s that I've enjoyed for the
past two months. I guess my smugness factor takes a hit too.

Life goes on.

 

JimboK,

Thanks for the comeback.

On my own, I completely missed the fact that the HV battery was probably
just as hot as the car's interior.

"Only Englishmen and mad dogs venture out into the noonday sun." Kipling?
Well, I don't want my beloved Amapola numbered in that crowd. So, lesson
learned: park in the shade.

I looked into that thread. There is a lot of hard info there that I'l have to
ponder on for a while before I can roll it into a hot weather strategy.

Today we went on our weekend errand drive-about. One place we needed to
go is ~8 miles distant. Usually, I wend my way there on city/suburban roads
at <35 MPH. It was only 97 deg F, but my co-pilot said "NO WAY, JOSE!" on
running without AC. So, since on the alternate freeway route the AC/ICE
would be running near full time at 55-60 MPH, and the AC hit wouldn't be as
noticeable, thats the way we went.

Don't know if it really helped the MPGs, but everyone was happy and sweat free.

 

Naptown,

Well done!

Any day you beat the old EPA mileage estimates on what IIRC is a highway commute
is a very good day... well, at least until you get to work.