Highway driving

yeah, power mode will give you more ummph. I think power mode changes the software that applies to the gas petal.

 

If you want max efficiency, avoid PWR zone. To keep it there even on the inclines, you need to plan ahead. Accelerate before the climb. The speed will decrease when you reach the peak but it wouldn't be that low.

How are you only getting 53 MPG? Are you charging? How long is your commute?

 

Check your tire pressure, for best fuel economy inflate the fronts to the max listed on the sidewalls of the tires (either 40 or 44PSI) and the rears to 2 lbs less. Grill blocking helps shorten the gas guzzling ICE warm up time. You might actually save fuel by having the ICE warmed up before you get to the highway.

 

For most people, the answer to that is YES.

If you have enough mental discipline and enough flexibility in traffic to manually allow it to speed up going downhill and then slow down a bit going uphill you might be able to do a bit better.
The difference won't be much and most people can't really manage it anyway........because they can't quite get the hang of it or the traffic won't allow it.

 

It depends on the hills. But if you want to go with the flow of traffic, without being an obstacle to others, then many hills do require going into this zone.

I don't believe that this necessarily has all that much impact on overall fuel consumption, especially when using just the first portion of this zone. Fortunately, the Prius ICE efficiency doesn't lose much efficiency for a fair ways into the PWR zone, though some of the additional electric conversion losses in the HSD may start adding up.

Climbing hills requires more fuel, that is just basic physics. The way you handle downhills has a greater impact on your overall trip MPG. If the terrain is favorable, an efficient downhill style will allow you to recover nearly all that uphill fuel penalty. But some common driving styles will waste it, recovering little. And some terrain will not cooperate with fuel savings, that is a cost of having hills.

 

CC is not smart to take on hills since it cannot "plan". Do it manually.

 

You said: "I have noticed that sometimes the car gets up to around 70MPH (probably on a decline), but sometimes slows down to around 49MPH! (probably on an incline)."

Which I don't understand, is the car driving itself? You are, I hope, controlling the car by using the accelerator pedal. What speed are you trying for? If you are using the pedal and avoiding the "PWR" region of the Hybrid System Indicator, HSI the speed variations are simply the results of climbing and descending hills and account for your decent fuel economy. Driving to keep the HSI in the right third of the wide portion, (pulse) or blank (coasting/gliding) will give the best possible fuel economy. Cruise control holds a set speed and wastes fuel with excess power up hills then inefficiently uses regeneration on downhills.

 

Try no mode. Push the power button twice. This is no mode or normal.h

 

No. Based on what you said in your initial post, I don't think you are a person who can
control the situation better than the car and it's engineers can.

I suggest setting the cruise control to keep up with the flow of traffic and just enjoy the ride.

Like the post before this, I didn't really understand what you were describing in the first place.

IF......you have the cruise set and your speed STILL varies by 21 MPH......and you are not in
REALLY steep mountains, then something is drastically wrong with the car.

 

Nice guy.

 

The power zone vs. ECO zone are all relative. The car doesn't suddenly become inefficient when you cross that border.

Use common sense and do what you need to, to stay at a proper speed in the conditions you drive in.

 

The "PWR" zone of the HSI begins at about 40 HP. Above 40 HP the efficiency of the ICE-CVT system falls rapidly. This translates to dramatic reduction in actual MPG. Even at 40 HP the PRIUS power to weight ratio is far better than a loaded SEMI, but it is worse than some lightly loaded trucks. I'm sure you've noticed some trucks slow down climbing hills, if you need to go faster than a loaded truck it'll cost you some MPG bragging rights and $ while the driver of a loaded semi has no such option.

 

Yes and yes.

It is impossible to drive the car and never have it go out of the ECO zone on the display.
Well maybe not impossible but VERY impractical.

Your first concern when driving should be SAFETY.
Having your speed suddenly drop 20 MPH is not safe.

In my opinion, you are putting too much emphasis on economy and not enough on safety and comfort.

(And I am not trying to insult anybody here; just trying to make sure the point is understood.)

 

When and where is it unsafe to go a little slower? If my slowing down on major hills causes the HUMMER driver to pass in an unsafe manner is it my fault? I have followed trucks on interstate 75 that slowed from 75 to 35 and had no issue with the safety of their driving. Has anyone ever lost control of a vehicle by going too slow? Many accidents have been caused by loss of control attributed to going too fast. Sure I drive defensively, courteously and economically and even make some accommodations for the aggressive road maniacs but I'm not the unsafe driver, they are!

 

I am a total proponent of driving slower. But there is obviously a point where driving too slow relatively to the flow of traffic definitely becomes less and less safe.

And the question isn't whether it's your fault or not, but whether it's unsafe.

 

... and I believable that the amount of economy loss he is fretting over is surprisingly small.