I'm confused...which is the MPG?

You are probably seeing an average MPG and an instantaneous MPG.

 

When you turn the ignition off, the reading you see is for that trip only. The other MPG reading is probably average for the tank overall.

 

To further explain- when you hit "trip" on the steering wheel you have three different sections it will scroll through- Trip A, Trip B, and Odometer. Trip A and Trip B are both resettable by holding down "trip," and the MPG shown for each of those (they will be different if you're using them differently) will be for since you reset that trip meter. I reset Trip A for each gas tank to track tank mileage, and have not touched Trip B since I bought the car so I can track the overall mileage for the car (just hit 60.0 yesterday!). When you're showing the odometer, the MPG shown is just since you last turned the car on. That is your mpg for your trip, which will also be reported when you turn the car off. I usually leave it showing that one, except to periodically check the other two.

 

The 1.3 miles EV is the number of miles you went while only using EV. The miles don't represent the entire distance you traveled. It should also show a percentage of your trip that was EV. The higher you can get that percentage in city driving, the better your mpg will be.

I'm not sure what you're getting at with "ODO in the drive info has only 13 minutes of drive time." That time spent driving should be the time since you last turned the car on. If it isn't- i.e., you've been driving for an hour but it says only 13 minutes- you should get your car checked out by the mechanic.

 

A ScanGauge or Ultra-Gauge will tell you what your instant mile per gallon is. It will go up and down a good bit depending on how you are driving. When running on the electric motor it will read 999. I find these gauges help me a lot in improving my overall fuel mileage, others may not.
For me they are a cheap way to improve my overall economy.
Dan

 

For clarification, which display are you looking at while driving? And you're positive you're on ODO, not one of the Trips? And you're checking the mileage right before you turn off the car (I.e. not just while you're on the highway)?

 

Not necessarily the case. If you are suggesting that driving on EV as much as possible is a goal for achieving high MPGs, that isn't going to help. The majority of the electric power is coming directly from the ICE recharge. A portion is coming from re-gen, but all of the power moving the car forward has its beginning in the burning of gasoline in the ICE. The best way to increase MPGs is to keep from jack-rabbit starts and heavy braking and by learning to drive within traffic flow in a way that allows you to glide (no energy use, whether ICE or EV).

 

Re: your last sentence. That is how the Liftback works.

 

While driving, while on ODO, the top of the display shows the MPG for that particular trip, from car start to car stop. When you turn off the car, it should match the MPG last displayed while driving. Similarly, the information in the drive info screen will show stats for that particular trip only.

Trip meters A and B show the cumulative mileage from the last time you manually reset the meter. It will not match the summary when you turn off the car, unless you reset it as soon as the car turned on. And similarly, the drive info screen will show cumulative info for the duration of that trip meter.

 

A priori, more specifically, I'm saying that gliding as much as possible- which, at city speeds, triggers EV- is what will attain the best mpg. The larger percentage of a trip the engine is off, the better mpg. You really do want to maximize the EV readout he's looking at (while not using too much battery). Just using a sliver of EV while gliding can do wonders for maintaining speed, too, while saving much of the battery.

Thanks for the opportunity to clarify.

 

Glad to have the clarification. Still, I don't think I agree with what I hear you suggesting.

No doubt: If the ICE is off, the car is moving, and no energy is being pulled from the HV battery (except to keep the one MG spinning ever so lightly and not to propel the car), you are maximizing MPGs. This is the very definition of a glide. Also: Relying on the HV battery to accelerate the car also is appropriate in certain circumstances (the very first acceleration from stop and in order to provide a minimal boost to avoid having the ICE turn on for a very short spin - say 15 seconds or so), but most of the time, use of the battery as a primary drive for the car is inefficient.

If you use more energy than you will recoup in regeneration, you will need to replace the power drain on the battery with a charge which diverts power from the ICE. This causes the ICE to run more inefficiently than necessary, because it will produce the power necessary to drive the car AND recharge the battery. You also have conversion and heat losses in both the generation and then use of the electric charge on the HV battery. Let the HSD computers figure out the most efficiency energy usage, while also seeking to maximize your glide time. Over the long haul, this will give you the best mileage.

Understand that I am not a hypermiler, so there may be others out there who see this differently than do I. There are a couple of different camps when it comes to the most efficient use of the battery at start up and Pulse. Some suggest very slow acceleration, relying on the HV battery until about 17 or 19 mph. This is not a reality scenario for most of us who live in some sort of urban/suburban world where that behavior will get you harassed, insulted, threatened, or worse. Another group will advocate nearly gunning the ICE in order to accelerate very quickly to the top end of the glide speed. This becomes effective, though, only if you run Glide sections through a pretty significant speed drop. Again, on desolate roads or multilane, non-rush hour roads, this works very well. For many people, it just isn't reality.

The way to see what produces the best mileage for you is to try a couple of different methods in similar scenarios. I know I tried the "maximize battery use" for a while, and I was thrilled with the very high sections and let down by the very low ones. I've found the best mileage for my driving world comes from using the ICE for acceleration, gliding as available, and timing my acceleration to avoid braking at nearly all costs (except for cutting off other drivers). I also try to use the down gradient of hills for boosting acceleration (very little delta for much more power) while using the up gradient to coast. The latter is very satisfying, so long as there is no one in my rear view mirror.

Your experience, as well as your mileage, may vary (and differ from mine).

 

A priori, you're not disagreeing with what I'm saying at all. I'm fully aware of how most people use the word "glide," and unless you're saying no one should ever use EV, at all, no, we don't disagree. I, and most people here, are also aware of how and when the ICE charges the battery. Both of your responses to me have nitpicked language instead of understanding the comprehensive meaning of what I wrote. Personally, I find that kind of discussion irritating.

 

I'm sorry to have offended you. It hasn't been my intention to do so. The problem on my end it that the full meaning of your posts was not clear to me. I was not certain you (a newer member with a new Prius) did have the understanding you do. I also did not want other new members or casual readers to take from your posts a wrong concept of the car. Too many people have bought a Prius and thought the "objective" was to maximize time on the battery power. They've viewed the various screens as part of a video game where piling up green regen cars and avoiding ICE use would provide them higher scores (higher MPGs), only to be disappointed in the end. I was concerned your post would not dissuade such thoughts. Again, please accept my apology for making these assumptions based on your posts.

As a further explanation, please understand my responses are based on many years of participating on PriusChat and reading many, many posts written by people who have not understood the HSD system. Worse, I've seen posts written by people who give direction and advice, not even realizing they have misunderstood the hybrid system.

I haven't known you or interacted with you before, so I had no idea of your level of knowledge of the HSD. The purpose of my posts is to add to the conversation in a way that should help (my perception, of course) PC readers better understand their hybrid cars. Clearly, the title of the thread shows some confusion on the part of the OP, so my input is not going to assume a high level of understanding of the Toyota HSD. Hopefully, your discomfort and mine, irritating as it may be, will help other readers get a better grasp on driving a Prius for better MPGs.