How is highway mileage so good?

Aerodynamics, it is the way the Prius is designed...

 

Couple reasons. The gas engine in the Prius is not the same as in the Corolla. The Prius engine is an Atkinson, which is more efficient than standard engines. Also, the electric motor is not dead weight, but is providing power to assist the gas engine. And it can get much much better than 48 on the highway. For me I get better highway mileage than around town, hi 50's easy.

 

I personally get over 50 mpg on freeways. Just to name a few reasons for the high mileage

- atkinson engine
- body shape
- electrical drive is not dead weight
- one could glide on freeways
- LRR tires

 

Lets not forget the engine is tiny, and the ECVT is making it more efficient.

 

it uses both for either, depending on what the software is sensing, it isn't one or the other like most other hybrids.

 

Should of rented a Prius.

SCH-I535 ? 2

 

Yes, the electric motor kicks in when power is needed. When there's a down slope, I back off on the accelerator and in many cases, the engine shuts off. Depending on how steep the slope is, I would either use the electric motor just to maintain speed or glide (no regen and no power input). I always try to use electric only when power requirement is low, like going down a slope.

Based on what I read, Atkinson engine is very efficient but lack power density. That's where the electric motor comes into play during acceleration.

 

I believe that whenever possible the Prius also proportions ICE and electricity so than whenever the ICE is running, it runs near maximum efficiency. For example, if it cannot quite run on electric power alone , it will start the ice, run it up to an efficient speed then cut back electric power or switch into charging mode to keep the ICE in that range.

 

-- Prius driveline losses may be lower.
-- The Corolla, depending on model year and maintenance history, may not have been using 0W20 oil.
-- The Prius transaxle, while not actually a CVT, does allow the engine to operate at near optimum RPM.

 

Under a light load (say, descending a slight slope) the engine can be turning 1200 rpm at 70 mph.

The system's very flexible and intelligent.

Also, don't forget the ugly wheelcovers. They play some small part too .

 

Several things. The Prius atkinson cycle engine is more efficient than a conventional Otto cycle engine, the stepless HSD IVT transmission makes for better efficiency and the Prius has a very low CD.

 

No other transmission in any car has so tall gears especially with so underpowered engine in low rpm that Prius has. You can drive 80 mph with only 2.000 rpm on a flat road, the only cars that can do that have 3-4 times torque of Prius engine and those cars (especially diesels) are the only one capable of high MPG on highway.

And of course low CD, LRR tyres ...

 

48 mpg on the highway? Only when I'm driving into a stiff headwind.....

 

How can you tell if you have a headwind or tailwind?

 

I am curious as to how anyone is getting high 50's on the highway?? At what speeds and for how long? My wife just drove to Ohio and back and averaged 43-46 but the car was literally a week old.

We typically average 48-53 mixed driving.

Have it in ECO mode and try to constantly monitor the MPG gauge and PWR gauge to get the most efficiency possible. Granted in 100 degree heat we are not going to skimp on the A/C so that would really only be the big drawback. Also we live in OK so hills are typically not an issue lol.

Dave

 

(this is a 2010, but no MAJOR engine or transaxle changes have happened since 2010)
As you can see, at about 62 MPH you should get 'high 50s' Check your local laws, while I am allowed to drive 40 MPH on MS freeways, one person claims the minimum speed allowed in FL is 60 MPH. I find it is often unsafe to travel more than 5 MPH under the speed limit.

Speed limits in the United States - Wikipedia, the free encyclopedia

 

You may want to check your tire pressure. My dealer only put 30 psi in my tires. I jacked it up to 40 psi. Jimbo's chart is a good reference. If you want more mpg, then you will have to reduce speed. Even though the Prius' body shape is optimized for aerodynamic, it still has to overcome the wind resistance.

If OK is really flat like you implied, you may want to see if cruise control could get you better mpg.