Road trip question

The faster you go, the greater the air resistance and the worse the MPG. Best speed is below 60. Your MPG depends on several factors including weather and driving conditions, but the one you factor you have control over is your driving style. I find the seats in my 2010 Prius to be very comfortable. There's not much to them, but they just happen to fit me right.... others find them uncomfortable.

 

1. slower is better for mpg - it takes a lot of power to push the air aside.
2. it depends on your back - stop every 2 hours and walk around the car a few times
3. anywhere between 45 and 55 MPG
4. You should run the A/C to cool both you and the battery. Windows open at 70 MPH might use more gas that having the A/C on.

Good Luck with your trip

 

Hurt you car? No it will not the car if it's in good condition.

Mpg has a lot to do with driving style/speed, road conditions, tire pressure and air temperature. It's impossible to predict what MPG you will get. I suggest you try to increase the tire pressure to 38 front and 36 rear - for a good balance between comfort and better MPG. The difference between 45 MPG and 50 MPG over 700 miles is about 1.6 gallons - about the cost of a BigMac. I would not worry about it.

 

1. Best speed to travel is slowest without pissing someone behind you off. But seriously speaking, no road is perfectly flat. I normally try to pulse and glide even on highway. If I see the road descending even a little, I'll try to glide as much as I could. Also, when the road is not congested, I glide in neutral. (please don't lecture me about this being illegal, this is no more dangerous than some idiot who drive 85mph or more)

2. The Prius sucks when comes to comfort. Not sure if it's going to kill your back. But I'm sure that you didn't buy the Prius for comfort.

3. I got 57.2 MPG during my 1100 miles trip to New England

4. It's hard to say how much. It depends on what the outside temperature is and what your set point is. I don't like working the A/C that hard so I just leave it at 77 to 78.

 

This study just in from Consumer Reports. They compared MPG of driving several different cars at 55, 65 and 75. The results are not surprising.

Consumer Reports shows fuel economy effects of speeding - Autoblog

 

Not dissing you, snoctor, nice link, but you'd think they could give us at least a little data. Jeeze. Nothing in this summary of the study, not even a percentage.

 

Yup. Unfortunately you need a subscription to CR to see all the details. I let my subscription lapse, otherwise I could have shared more. Like you I'm hoping somebody else can post more details.

 

Lol! Just drive it! FWIW, I keep my AC on 76 with econ mode on and I noticed very little impact from the early spring when I didn't have to run AC at all. The terrain will have a lot to do with what mileage you get. I have a hilly commute 100 mi each way, three days a week, and I set the cruise on 70 and get 50mpg. YMMV.

 

Just got back last night from a 620 mile trip that had a climb to 6000' feet in the middle of it from Orange County, CA to above Fresno.

Stayed between 60 and 65mpg for the duration and netted 55.7mpg for the trip.

FWIW, it was 106 degrees for over 4hours of the drive up. And for much of the drive home on the steep downhills I let it run past 70-75mpg.

 

I just did a 6 day trip from sacramento to ashland oregon. Average speed 68 and mpg 51.5. Lots of hills and ran AC as it was high 90 low 100 in temperature. 900+ miles and did great.

 

Hm, new measurement methods for speed (mpg?). We still use MPH or km/hr.
Best mileage is attained around 45-50 MPH. Take secondary highways for better mileage and more interesting scenery.
Also often less traffic.

 

we drove from Tallahassee, Fl to LA, Ca, kept it around 72 mph, and avg 48 mpg, no need to really spped and get all stressed out, the A/C wont hurt your mpg, these cars run off an electric compressor and not off the motor.

 

There is no free energy. The electric AC is still powered by batteries which is powered by the ICE. AC use will still hurt mpg. It is 10%-20% depending on ambient temperature. We drove about 1000 miles from San Francisco to San Diego. I averaged 80 mph on the highway and got 47 mpg with AC on 76-78. Ambient temperature was in the 80's so AC mileage degradation was minimal. If it were 100 out, then I would expect my mpg to drop another couple of miles.

Based on OP's plan, he should get about 50 mpg for the trip. Prius seats are not the most comfortable thing. I've made this San Diego drive many times. I can say that my back feels better in the Prius than driving my old Civic or Corolla. But by far, our Sonata is the better road trip car in terms of comfort. My back, my ears, my foot, everywhere is a lot more comfortable. But, the 50% savings in gas driving the Prius will trump it.

 

My future wife and I have taken a couple trips in the Prius between MI and VA. We leave the A/C set at about 70. I set the cruise control at 72 or 73 and average about 52 MPG. She hates using the cruise control and her speed ranges between 65 and 80+ - kind of a natural pulse & glider. She averages 60 MPG. Go figure.

As for comfort, I get a bit sore after a few hours of driving / riding, but no worse than other vehicles. I'm fine after a few minutes out of the car. We keep a soft cooler with a flip-top behind the driver's seat filled with water and soft drinks. Snacks are in a bag behind the passenger seat. Remember the space below the rear floor for items you don't need on the road or dirty laundry on the way home.

 

1. Using cruise control with no elevation change. 72 mph will get better fuel efficiency than 75 mph. At about 50 to 55 mph you get a bit higher than 60 mpg on E10 gas on a smooth dry road on warm day using a 3rd gen Prius if you driver longer than two hours and go . If you up your speed to about 65 mph your mpg will drop to about 53 mpg -still not bad. If you go 70 mph your fuel efficiency drops to about 48 mpg. If you go to 75 mph your mileage drops to about 46 mpg. If you go up to 80 mph your fuel efficiency will drop to about 44 mpg. The Prius get better MPGs going downhill and worst MPGs going uphill.

2. As long as you dont over inflate your tires over the max side wall - the 3rd gen tends
to absorb most of the road bumps you find on a superhighway and your back should be fine.

3. see (1)

4. At above 55 mph A/c drain is insignificant compared to aerodynamic drag forces


The simple ways to get better fuel efficiency,

1. give yourself more time to get to your destination
2. drive when there are less traffic on the superhighway (non rush hour)
3. don't go over the posted speed limit - lower speeds better MPG
4. avoid caffeinated drinks so you can drive longer without stopping - less stops better MPGs
5. check to make sure your tires are properly inflated
6. drive in good weather - avoided wet or icy roads.
7. avoid using a roof rack or roof carrier.

Last year, rushing home at 80 mph from Missouri to Maryland (+14 hour drive) on the superhighway in the rain I achieve one of my worst tanks with respect to fuel efficiency -- 44 mpg.

This year I decided to do better, I time shifted a major segment of my outgoing trip from Md to Mi (+11 hr drive) to be outside of rush hour by starting my trip at 8pm and driving all through the night (which made it easier to go at a slower speeds and to hypermile - the results were promising - I able to achieve 61 mpg (calculated at the pump) for one tank. On the trip back from Mi to Md - I wasn't able to time shift and my MPGs dropped to about 54 mpg.

Gaithersburg, MD to Grand Rapids, MI
61.3 mpg (621miles/10.1gal)

Grand Rapids, MI to Gaithersburg, MD
54.9 mpg (580miles/10.6gal) +50.0 mpg (58.5miles/1.2gal)


My numbers were good enough to win the Marathon class in the Cleanmpg.com's FE (Fuel Efficiency) Challenge 21 Spring 2013, see.

FE Challenge 21 - Spring 2013 - CleanMPG Forums