How is highway mileage so good?

Learn to feather the throttle! A light foot is better than a lead foot.
When you start downhill, back off the gas, let gravity help. When you go up hill, watch the speed. 65~70 is it, otherwise, MPG takes a hit. I do not use A/C, this helps. I have windows, they actually open!
This last fill, 2 days ago, I hit a personal best, 51.4 MPG in my Gen II.
Baby's doing just fine!

 

I find the Prius is wonderful for letting me know wind conditions, because of the instant MPG display. I can confirm by checking flags to see if I'm right.

For example, when I cross the San Mateo Bridge, I can expect to average ~ 65 mpg and 1120 - 1280 rpms holding 60 mph (displayed). If I'm going into a headwind (stiff), I'll see the RPM's up to 1500 - 1600 and the instant mpg reading between 45 - 50 when I'm traveling 53-55 mph.

 

Thanks guys, I will double check the tire pressure tomorrow when I get home.

Oh and I refuse to drive around in a new car with a 110 + heat index with no ac lol

 

Do NOT do that, batteries hate heat and you have two of them in the passenger compartment with you. If you stay cool, they stay cool, and last longer.

 

We don't expect you to do that. LOL. I normally set my A/C to 77 and leave it in Auto. I still get over 50 mpg.

 

Yes, use the A/C but use it in conjunction with the ECO button. Allow the A/C to run in Recirculation mode
on auto with the temp set above 75°. It will maximize your MPG's by minimizing the A/C power usage on the battery.

 

Well I guess that is my issue, I leave the ac on low all the time lol.
77!? I will deal with my lower mpgs haha

 

A/C has minimum impact on the highway, it can use up to 1,700 W at start but then it settles down at 300 W to 700 W. This represents only 2 to 5 % at average speed of 50 mph, maybe even less.

 

We are right at 4500 miles now, mpg seems to be getting better than when it was brand new

 

I've seen this plot before and would really like to know how things were determined. It's so much different than fuelly, and fuelly agrees almost exactly with my experience (45mpg highway and 50mpg city for an average of about 48mpg).

 

Fuelly is an average, per tank MPG. The graph is instant MPG data. It's speed VS MPG at different speeds.
IE @ 50 MPH he's getting 67 MPG. At 65 MPH he's getting 60 MPG and at 80 MPH he's getting 40 MPG.

 

Some things can help with the heat (you may have already done some of these, but if not....)

A - Try to minimize the heat that transfers and gets trapped in the car. The interior (especially the seats) can trap and store heat. When you drive, remember, you aren't just cooling the air, but also the interior of the car. So try to keep your car as cool as possible.

1. Get your windows tinted with a film that will reflect heat (such as ceramic tints), to reduce the heat transferred into the car through the windows.

2. Get a windshield screen (and other window screens if you are so inclined). There are some available in the PriusChat shop and sales help support the site.

3. Park in the shade whenever possible. This will minimize heat transfer through the windows as well as the roof and doors.

B - A/C usage. There was a debate and it seemed that the conclusion was to use "Auto" for the A/C and let the car figure out the temps (rather than setting a temperature and using the fan). Try to go down in increments and keep the air blowing on your face to make it seems cooler.

1. Start at a warmer temperature (80 F for example) and let the car run on auto. The fan will still kick on near high if the car is really warm. As the interior cools down, the fan will decrease, when it gets down to 2 or 3 bars on speed, reduce the temperature by 2 degrees. Repeat. You will find that by the time you get to 76 or 74F the car will seem comfortable (hopefully) and the car will likely keep the fan running at a constant 2 bars.

2. Use ECO mode in the car as it helps the efficiency of the A/C unit.

3. Turn off the A/C unit about a minute before you shut the car down to dry out the box and vents a bit. This will limit the build up of mildew and a moldy/smelly sock smell from your vents. (not unique to the Prius).

 

Yup just learn how to feather the gas... i drive 125 miles round trip every day from northern Utah to central Utah and i am getting almost 53mpg and this morning when i turned off the car it said the mpg was 54.6 and this is in a 2013 Prius 2 with about 300 miles on it.
Pretty remarkable IMO

 

My commute doesn't include any interstate, but last week I drove a 150 mile trip, of which about 100 miles was interstate, and the round-trip MPG was 61.0 (indicated); Amazing! Summer temps around 80F, kept speed between 65-70MPH, with climate control in auto, a few degrees below outside, so A/C was on the entire time. Just basic economy driving, keeping as light foot as possible on the pedal to keep speed above 65, staying in the right lane nearly all the time. Used ECO mode the whole time, to reduce A/C affect on mileage.

My Prius likes summer .

 

my drive home last night...

 

I cannot believe that no one has brought up the information that AC is more fuel efficient at high speed than having windows down. You people are letting me down.

 

It's whether you Burp or Fart!

 

Look at plants that are away from the side of the road and have flexible branches or stems.

 

I just bought my prius 3 last month. I live in Lawton,OK and I have made 2 trips to Tulsa and 1 to Dallas. I have 3500 miles on it now. Seems to have a mind of its own sometimes. Going to Tulsa, got 43 MPG and went to Dallas got 42 to and 48 back to Lawton. I drive 37 miles to work and one day I can get 48 to work and the next get 56. On way home get 44 MPG. Some hills but nothing like between Lawton and OKC. I have figured out to drive 65 on highway and it get better. Like you, AC is always on. Got windows tinted fist week. Big differance.

 

Driving on way to my brother's house one way is around 440 miles at 65-70 mph speed limits and the worse tank I've gotten was 53 mpg pencil & paper and the car was filled to the hilt. Cruise control can be your friend.