How frequently do you use HSI RED Power range

I think going into the"RED" is unavoidable in traffic when sarting from a stop. I do try to minimize but things happen.

 

Don't worry about temporarily going into the red when accelerating from a stop. But when at cruising speed, try to keep the bar in the middle position as much as possible. The middle position indicates the optimum mix of power from the internal combustion engine and the electric motor. I used to try to keep the bar to the left of the middle position, but that doesn't lead to better mileage since then the battery needs to be recharged much more frequently.

 

I think that's the right way to go, I do go into the red when accelerating but try to keep it to the middle range.

 

I personally never use the power section of the HSI ever. I guess I shouldn't say never but almost never and if I do it is usually accidental.

 

How often? Every time I start from a stop, unless I'm in a parking lot. I get up to speed briskly and then back off. My average mileage on fuelly would be much better if I didn't spend 80+% of my miles on the freeway at 75 MPH. Also, winter really pulls down the average.

 

i find the gen III a bit more sluggish than the gen II. if i have traffic behind me at a light, or going up a fairly steep hill, i definitely hit the power range. if i can take my time, i stay just short of it. but it's like 'come on already!'

 

How frequently, every time I take off from a stop. I "tickle the right hand side of the power bar" every time I accelerate. I get up to speed quickly and then I am able to glide more quickly.

This also helps me keep up with traffic and not hold anyone up around me.

 

I try to never get in the Power zone but it is inevitable on my commute. I have a very long and steep grade that I have to go up in the morning. It is about 10miles long and really kills my mpg. I have to stay in the red just to maintain 60mph. I also have to get into the red on nearly every on-ramp I use. It helps me from becoming a hood ornament. LOL

Wen I am working on higher mpg tanks I try to find alternative routes that don't require such fast acceleration but I still hit power mode quite frequently.

 

I don't have a grade nearly that steep but the grade plus the distance is what kills. This morning I dropped from 70.7mpg to 68.4mpg on my morning commute and that was with 301 miles on the trip (i.e. it takes a lot to change mpg). When I go home I will be lucky to get it back to 70mpg since the best average for this commute would be about 65mpg although 69mpg avg. is possible if the conditions are just right (54mpg uphill and 85mpg downhill).

 

"Keeping up with traffic" is ambiguous. Smooth is what counts, not speed. If you are still using your old (typical) driving style of leaving no more than 0.2 car lengths between vehicles, you have given control of your car to the driver ahead of you - and he's a dolt. I can go just as fast as the rest of traffic, but just by using the safety recommendation of 1 car length per 10 mph, I can significantly smooth out my driving - and boost my fuel economy - without lengthening my commute. And by taking a Valium and giving up on the idea that nobody is going to pass me, I am more relaxed and sane - and it's surprising how few actually do pass - of course there's always that guy that passes me 17 times on the way to work, but he seems to spend a lot of time braking, thereby letting me catch up.

 

Glide....... That is the only technique you really need to know to boost your mpg. Driving slower helps immensely as well. Somewhere someone wrote how speed doesn't affect fuel economy but aggressive driving does. This is 100% false. High speed does negatively affect fuel economy and aggressive driving makes it even worse. I guarantee that if you drive smoothly at 50mph and 75mph you will turn out a much higher mpg number at 50mph. So slow down to a speed that will keep mpg high yet still be safe and not annoy too many people and you'll notice an increase in mpg. Use gliding techniques at every possible opportunity and you'll start hitting the 60mpg target in no time. This assumes you make trips over 10miles so the car has time to warm up. Bob's graph hold pretty true.

 

I don't normally get into the HSI Red Power range during my commute.
However, on my annual road trip through Pennsylvania when I climb up through the moutains - I sometime will get into the HSI Red Power range ... +2 gallons per hour just to keep the Prius from falling below 30 mph on some segments . Coming back down the mountains, I aggressively glide on the downhill and work to bring back the Prius' overall fuel efficiency numbers back up.

 

Can someone with a Gen III do the following experiment for me?

Starting from a full stop, accelerate, and see how long it takes to get to 45, 55, or 65 MPH,
1) Accelerating the entire time in the middle of the PWR section of the HSI.
2) Accelerating the entire time in at 3/4 of the wide HSI bar.
3) Keeping in Electric mode until 16 MPH, and then going to 3/4 of the wide HSI bar.

Please only do this if you are prepared to use a stopwatch and average at least 2 trials.

Thank You Kindly.

 

Rarely ever go into the HSI power range unless I'm going up a really steep hill.

 

Daily but only to the first part, very seldom all the way. I drive by the ScanGauge engine RPM and try to keep it below 3,200 rpm and closer to 2,400 rpm.

Bob Wilson

 

I have noted that if I just hold it on the border when starting out from a light, I tend to get the right timing on the next one. So if you tend to miss the next light, try slowing down a little.
I try to avoid going into the red at all. I read somewhere that going halfway into the red has only a small effect on efficiency, but try not to fill it up.

 

I tried this today in a Gen III with solar roof, no passengers, no significant cargo, and nominal tire pressure. Eco mode was selected, the windows were up, and the air conditioning was off. I tried each acceleration method you suggested on four different stretches of road. They are all fairly level, but each has some slight incline. The first two go slightly up, and the second two go slightly down. I timed going from a standstill to 40 mph and 45 mph. I couldn't measure the higher values because of the speed limit on the road I was using.

I took "Electric mode" to mean keeping the HSI in the left half of the wide bar, as close to the middle line as possible.

Here are my measurements of the time, in seconds, to reach the indicated speed. The four readings are along the same four stretches of road, in the same order every time. (Indeed, the 40 and 45 mph values are from the same trial in each case.)

method 1, 40 mph: 27.4, 21.2, 14.2, 14.7; avg 19.4
method 1, 45 mph: 44.9, 26.1, 17.6, 18.8; avg 26.9

method 2, 40 mph: 29.6, 35.4, 20.5, 22.6; avg 27.0
method 2, 45 mph: 45.6, 41.2, 25.5, 29.7; avg 35.5

method 3, 40 mph: 30.9, 38.6, 24.0, 27.9; avg 30.4
method 3, 45 mph: 49.3, 44.9, 29.3, 34.8; avg 39.6

There are various ways to interpret and analyze this data, so have at it. One thing I notice is that the stretch of road appears to have a lot of effect on the outcome. The first stretch looks almost the same regardless of method. That stretch of road gets steeper in the latter portion, which may explain the big gap between 40 and 45 mph in method 1; all the other stretches of road get to 45 much sooner after reaching 40.

Given the "road effect" pattern I see here, I'm inclined to use method 1 as a baseline for each stretch of road and divide the times for the other methods by that. Excluding the first stretch of road as an outlier and averaging the other 3 ratios gives a 54% increase in time for method 2, and a 77% increase for method 3. And given what this data indicates about the first stretch of road, it would appear that the results could be quite different if the road isn't level.