Best way to get maximum MPG for long trips

hello pria,

welcome to PC. anyways, there are MANY other people that know more than me, but there are certain things you can do.

CONSUMPTION gauge - watch it on your peripherals! watch the yellow bar, and try to drive so it's the highest it can be. dont be afraid to use fuel, but dont "DRAG" your consumption on it's lowest point. accelerate, then lift off and try to keep the yellow bar as high as possible.

you can set your CC, but if you feel it drag, lift it, go a bit slower and then accelerate on a decline. doing this, you should average 45+ on any highway.

good luck, just my advice.

 

If you've made up your mind ahead of time that you will exceed the speed limit, then you might as well not ask the question. Speed costs; how fast do you want to go? Rhetorical question for now, but one you need to answer for yourself.

For the Prius, fuel economy decreases pretty much linearly with speed above 40 MPH. I understand if your highways are busy, and I agree that to go 55 may be a safety issue. There are highways in my neck of the woods, however, that at times have traffic light enough to allow 55 MPH safely.

Having said that, terrain will largely determine the most efficient method. On terrain that's flat or nearly so, cruise control is probably your best bet. On hilly terrain, CC is very aggressive in trying to maintain speed, and does so at the expense of optimal fuel economy by pushing engine RPM into inefficiently high ranges. See this for a (somewhat technical) discussion of an alternative technique for hills.

 

This last Saturday the wife and I drove down I-65 to Louisville, KY from Indianapolis. We weren't in a hurry so we settled in a few car lengths behind a semi who was doing 64 m.p.h. and reset the MPG display. Outside temp. was about 85, little or no wind, and our A/C was set comfortably cool at 72. As we pulled into our hotel garage 95 miles later, the average m.p.g. display said 61.8.

Drafting semis was on an episode of Myth Busters. It works. I wasn't dangerously close IMO, but a little closer than a normal safe following distance would dictate. In my experience, similar speed and conditions without the semi would have resulted in mid-50s m.p.g.

We returned home the next morning with an extra person, more luggage, and a need to get back. I set the cruise to 75 and the bars read 46 to 47 all the way home in "clean air" (no semis).

FWIW

 

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Perhaps you might gather some data to add to our knowledge. Break up the trip into 1.5-2.0 hr. segments and run each at a different cruise control speed and record the mileage and conditions for each segment. Bring the data back and we can compare it to:



You'll notice we have a gap at 65 mph ....

Bob Wilson

 

I'll add my "Welcome!" as well.

Now seeing as you are new here, you might not be familliar with some of the acronyms, abbreviations, and specialized terms that are common at PriusChat. Some of our regulars forget that these aren't typically used in the average person's daily conversation.

Scientific Wild A** Guess

Miles Per Gallon - Fuel Economy

"Dino" = Dinosaur as in motor oil distilled from crude oil pumped out of the ground instead of synthetic oil.

10% Ethanol Reformulated Gasoline mixture.

Multi-Function Display (that little computer screen in your car

The touch screen "reset" button on the "Consumption" screen.

Electronic Cruise Control

Hmm, first time I've heard this term. Seems to indicate using cruise control, but turning it off for hills.

Watching the "Energy" screen and pressing the accelerator such that the Internal Combustion Engine is both powering the wheels and recharging the battery (as indicated with the arrows on the screen).

Toyota's Hybrid Synergy Drive drive-train as used in the Prius consisting of Internal Combustion Engine, 2 Electric Motors/Generators, and the wheels of the vehicle all connected together with a single planetary gear.

 

WHOA!!!!!!!!!!! look at those graph's!

we're not worthy. i thought of just giving opinions here, but my goodness. the tech guys come on and games over.

good info people. now, if i can only figure out my HTC mogul.........................

 

Hi All,

The Graphs need updating to include SHM. After a few miles constant speed on the highway between 50 and 55, the SOC gets up to 62 %, and then one can feather the throttle to a very low RPM. At 50 mph, level, and no wind this is about 75 mpg. At 55 level and no wind the result is about 65 mpg. I commute to work at 53 mph, and about 70 mpg for the highway portion, after the SOC has come up.

Of course uphill and head winds will shift the speeds, RPM and mileage around. Its more typical for me to average in the high 60's on the highway commute portion, consequently. Which is actually a challenge to keep up with , on secondary road commuting because of the variability of the light time, when one commutes across the grain (here in Chicagoland, everything is set up radially out from Chicago, and circumfretial routes are all screwed up).

On local road driving, the SOC runs more like 50 to 55 % and one cannot get the car to stop charging the battery on the short constant speed portions of a "city" / suburban drive.

 

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<AHEM> The graphs are complete because they are reproducible. The "SHM" advocates need to plot their own data. As my drill instructor used to say,"A grain of observation out weights 10 pounds of <an alternative> any day."

Bob Wilson

 

I drove over 5,000 miles in three weeks last June (2008) and tried to keep it at 55 unless there was a lot of traffic and felt I was a hazard. We achieved an overall average of 53 mpg and were pleased that we could enjoy the scenery more than usual using the lower speed.

We drove from Roseville, CA to Zion Park, Denver, CO, Bloomington, IN, Minneapolis, MN then back through the Black Hills, SD to Salt Lake and then home.

I did get Pierre (pee-air) up to 85 for a few minutes over the salt flats West of Salt Lake City and was pleased with the handling and performance.

So, my advice is to sit back, relax and enjoy the countryside and the great mileage.

 

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I try to avoid drafting behind an 18 wheeler. It is one of the best way to get a nice paint chip from flying rocks.

 

I drove my Prius on a nice 800 + mile run an stayed pretty much around 68 to 65 mph. My average mpg turned out to be 51 mpg.

 

Don't put on a rear bike carrier with 2 bicycles hanging out in the wind at 70mph! My usual 49-51 mpg highway dropped into the low 30's () on this past weekend's 500 mile highway road trip. I'm going to try to fit them inside the car next time!

(I don't think anything else was wrong, when I traveled at under 50 mph my fuel use was normal)

 

Actually, it is very simple.

On long trips, you will be on the highway. This is when Prius spend about 75% of the energy pushing through air. There is no way around it other than slow down.

If that is not a choice for you, then second best choice is to drive in a group with other cars. This means drive behind other cars (or even better, large cars/trucks). Be sure to leave a safe distance in front. Do not travel alone in out open pushing through air by yourself. Think as if you are a bird on a mission of migration.

Typing this up reminds me of a joke. I'll throw this it in here.....

Why do birds fly south during winter?


You probably say because it is warmer. The anwer is because it is too far to walk.