I stopped updating the tanks on the site due to some short fills that weren't recorded. We have been getting no better than 45 mpg this summer in one of the driest summers on record. 1" of rain in 3 months. Given the so-so summer mileage, I won't be buying a block heater. If I'm going to plugin the car, I want it to be charging for total electric operation.

The car rarely goes over 50mph and is often used for short trips of 5 to 8 miles. It appears that it's trip length and hills that are killing our mileage. Or good mileage varies a lot from car to car.

 

Other new Prius owners, and new car owners in general, have written that a new car needs a good 5000 miles on it to get through its break-in period. Effeciency in any new car is not great until the engine is broken in.

I wonder whether you have to travel up steep hills frequently. Hybrids have very heavy batteries and thus weigh a lot more than conventional cars of the same size. The need to haul those heavy batteries up a steep hill affects mpg significantly. I live at the top of an 800-foot-elevation, 1.5 mile hill with many sharp turns, and I see the instantaneous mpg drop into single digits several times as I drive that route. Then it drops below 5mpg as I drive up my very steep driveway. That's just the way it is: the current generation of hybrids simply does not benefit people in my situation as much as it does people who live in flat country.

 

I hit big hills all the time here in California and got 51.5mpg on my second tank. Ever hear of Mulholland Drive or Laurel Canyon?

Going uphill you just have to let your mileage be crappy - push the gas hard and just get the hill over with. The higher demand on the gas engine is good for it - it runs more efficiently at the higher rev. That can seem counterintuitive as you probably want to go easy on it when mileage is on your mind - don't.

Going downhill you have 4 strategies, and it's all about picking the right one:
* Light decline: Let up completely on the gas so the engine turns off, then press lightly until you see on the display that the battery alone is pushing the car. This is "Warp Stealth" - you're using 0 gas but still maintaining speed downhill.
* Medium decline: Let up completely on the gas to turn the engine off, then press even lighter until you see the regen arrows go away - there should be absolutely no arrows on the display. This is Coast/Glide. Sometimes you'll feel the car surge forwards when you hit this mode, because nothing is engaging the wheels anymore - they're just spinning everything freely. 0 gas used and 0 battery used.
* Sharp decline: Let go of the gas, and let the regen slow you to maintain your speed. Your feet are doing nothing in this mode.
* Very sharp decline: Brake very lightly to maintain speed. If you're going too fast brake a little bit more, but always vary pressure slightly. If you brake hard then roll, brake hard then roll, you'll use the brake pads on the wheels and get minimal regen energy fed to the battery. Riding the brake is GOOD on the Prius which is harder and harder to learn the more you're used to driving legacy cars.

Vary these strategies as the decline of the hill changes - you don't need to stick to one per mountainside.

Typically you'll see your gas tank drop significantly on a big uphill, and your battery to some degree - but by the bottom of the other side you'll typically have a full battery and 0 gas used since the crest of the hill.

The main trick is to practice hitting that Coast mode - the screen has a little bit of lag to it so once you can feel the car turn the gas off, and feel the car let the wheels turn, you'll be able to get to Coast mode faster and maintain more speed going into it, than when using the screen - plus you can keep your eyes on the road like you should be!

Above all, if you can find an open lane to Coast in, that's your absolute best gas savings. Regen is cool on the Prius as is the efficient gas engine and its ability to accelerate on battery alone - but the truth is converting energy in any direction - from battery or gas to momentum, or from momentum to battery - loses energy in the conversion. Nothing saves gas like the no-arrows-anywhere mode (Coast/Glide), because you're not converting any energy in any direction.

 

I have to agree with you. I have a 45 mile commute each way with some good hills in it and I also find the best way to do it is to get to the top as fast as you can and then let the car go into stealth mode etc. I like the 4 diffferent methods you mentioned. Got the car 2 weeks ago and have put 1000 miles on it. The first tank, I got 48.7 2nd was 52.3 and the one I am on now is at 52.3 also.

 

From my short time as a Prius owner, I've already noticed the three biggest factors in MPG:

1. Who's driving the car.
2. Where you are going.
3. How fast you are going.

For example, we bought the car two weeks ago. I traveled on business for the week and my wife used the Prius to commute to work every day, about 40 miles a day. When she picked me up from the airport (after circling for an hour) she had done a great job - 51mpg for an average. This was our first tank, so I was really happy.

We filled up again this Saturday and then went on a road trip - about 250 miles roundtrip and mostly highway driving. I drove, and brought the MPG all the way down to 40mpg. I was going about 80mph most of the way (also hit 100 at one point just to see the digital readout hit triple digits )

So really, it all depends on your route and driving style. Still, I must say, going 80mph and getting 40mpg is really good. I'm sure my Honda would probably have only given me 27-30 in optimal conditions.

 

That's great, though 40 miles is not a short trip. Our trips are 5-10 miles, in hilly country. Both my wife and I are getting the same mileage. Speed limit max is 50 though most of the time this is on roads at 40 mph or less. But yes, the Prius is doing much better than our Honda under the same circumstances.

What we've learned is that we really want a total electric car for our normal daily driving. If on a trip, we'll use the Honda.

 

After 200 miles in my 4 day old Prius, I topped off with 5 gallons (had to keep pumping after it stopped 3-4 times). The average is 40 also, but I suspect the tank from dealer was not full. So I am about to try out the first "full" tank.

I am thrilled with mileage so far (Consumption screen estimates 46 mpg), but am not pleased with how quickly the engine kicks in even with full battery and accelerating slowly. So a EV switch modification and more air (nitrogen) in tires will be done after the next fill-up (I want to know what mileage I get before and after the changes).

 

ck, the Prius is crafty about turning on that engine; it's going to turn on when you start the car up no matter what to get all the fluids moving and everything warmed up - but after that, you'll notice that your battery level ("SoC" around here) plays a big role: Green bars (lots of them) will keep the gas engine off unless you practically floor it; pink bars (half of them gone) will kick the engine in, even when you're just trying to Coast/Glide. The computer tries hard to keep that battery level in the blue bars at all times. It's better for the battery, and theoretically ready for any situation.

Unfortunately, sometimes it's also annoying; I kinda wish there were some Expert buttons on the wheel or something to tell it "No, there's a downhill coming up - use the battery not the gas for now" or "turn everything off for now" or "use the gas as much as possible," "get max regen out of the brakes but don't use the pads" - magic buttons like those. Coming out of Glide mode because you hit a bump is annoying.

 

Soopah, thanks for the color code/ICE explaination. I have not seen pink, mostly Blue and sometimes Green (after highway, high speed driving). I too was hoping for an "expert" switch, that will let me go from traffic light to light, flat or down hill, between 25-35 mph, without using gas. Even better if I can turn that switch on-off while moving. Closest thing I can think of is the EV switch, but I guess that is not EV switch is intended for.

 

Yeah, the EV mod would be interesting, and the rest of those expert switches installed as a panel even better - wonder if that's out there. If only I were an Electrician.

On the way the Prius uses gas, you should actually feel grateful; that's a feature the Honda Civic Hybrid lacks. You fill up the battery, it uses electric power the same way as it would if the battery were half empty - no calibration by the computer. It's not something that would probably occur to a conventional car driver, but as a Prius veteran, it drove me crazy - felt like a big step backwards.