Last post on Dec 05, 2013 at 1:00 PM
You are in the Toyota Prius
What is this discussion about?
Toyota Prius, Hybrid Cars, Fuel Efficiency (MPG), Sedan
#482 of 998 Re: mileage [rockpsl76]
Jan 12, 2008 (1:58 pm)
ONe of the biggest drains on all vehicles, hybrid or not, is having to accelerate from a dead stop. Overcoming the inertia of standing still is a HUGE waste of fuel. There is no way to obviate Newton's Laws.
I did a similar test on the streets of NYC where I used to live and work. Going across town from stop light to stop light to stop light I was only able to achieve about 35-40 mpg, this with a fully warmed up vehicle. However going south along one of the major Avenues at a constant 25 mph I was able to achieve 70-80 mpg!!!!!! Same trip, same vehicle, same city, same everything excluding the stops.
This is one of the few unknown limitations on driving no matter the vehicle. A good solution would be to replan your route if possible to avoid the stops.
***65,000 mi on my 2005 ( nowhere near carbot's 2004 ) with a calculated fuel economy of 47.9 mpg ( 2.09 gpc ) as per GH database.
Regarding the fuel capacity questions, dont worry. I'm pretty sure that no one explained to you that you have two gas tanks in your Prius???? Huh?
Actually in order to reduce/eliminate evaporative emissions there is a fuel bladder inside your tank. When the vehicle is new the bladder is still stiff and not expanded to its full capacity. This is doubly true during cold weather when the bladder might be stiffer than normal in the cold AMs. As the weater warms up and the bladder breaks in you will find that as you get down to one bar you will put in about 9.0-9.5 gal when the last bar begins flashing. This is intentional, not only with the Prius but with all Toyota's ( e.g. the light on the Camry will come on when you've used about 16 o/o 18.5 gal ).
As carbot noted you can drive a good 50 mi safely before you must refill.
#483 of 998 Re: mileage [newpriusowner]
Jan 13, 2008 (9:08 am)
SOC is "state of charge". It's calculated by the cars computers (power in - power out) not assumed by looking at the voltage.
Funny, I looked up -again- the document on the warm up stages, and it appears there are actually five. It's complex and appears at:
These are enthusiast named states of operation. I don't believe Toyota uses this description.
Note that the "EV" (electric vehicle) switch is not installed in the North American models, though the programming to operate the car using it is. If you do want to install this switch, you can purchase a "stock" Japanese one. You will void your battery warranty though. What this switch does is extend the parameters for electric only operation. The car will still start the engine and use it if it needs to.
Stage 4 is the preferred one to be in, as the car is fully warmed up and will have the best chance of getting good mileage.
#484 of 998 1st tank of gas
Jan 13, 2008 (4:25 pm)
Today I hit 1 bar left on the gas gauge. Not wanting to push this, and to check how much gas I had left, I filled up. I put n 8.756 gallons and drove 430 miles. This equates to 49.1 mpg with just over 3 gallons left in the tank. Now I know I can easily drive 100 miles when I hit 1 bar and was pleased with the 49 mpg for the 1st tank.
#485 of 998 Re: 1st tank of gas [scottc3]
Jan 13, 2008 (6:40 pm)
You're making a dangerous assumption. The fuel tank capacity changes due to the bladder being more or less "streatchy". This is one of the reasons Prius owners run out of gas more than -any-other-car-! I've seen reports from owners who have only gone 40 mi. on the last pip.
So don't get mad at anyone but yourself if you run out. The car gives you lots of warning.
I must be of Swiss heritage. I fill up after the car gets below 1/2 tank on the gauge.
#486 of 998 Re: 1st tank of gas [pathstar1]
Jan 14, 2008 (8:45 am)
LOL.. I'm in that group but I'm aware of my personal predilictions. I tend to push that last bar....but I've been rewarded with the 'triangle of death' 4 times.
#487 of 998 Re: mileage [pathstar1]
Jan 14, 2008 (8:47 am)
I am a new Prius owner. Purchased a 08 package #6 last Tuesday. I typically drive 40-50k miles per yr and spend most of that time on a highway. in just 4 days I have put almost 800 miles on it. Live in MN and dealer tank gave me about 34 mpg, second tank gave me 43.8 mpg. Currently on third tank and reading about 38mpg (but it is also currently -15F temps).
Could you please explain to me what the various stages of the ICE are? You mentioned Stage 4 mode to shut the engine off if not required.
Also, should you normally be able to show a battery full charge (all bars)? I haven't seen that happen even once on mine. The best I can get is 1 bar away and only for about 2-3 minutes. However,I do need to bring it back to the dealer as when I'm coasting the blue arrows go from the tires to the motor to the battery, but it doesn't change color when braking. (I test drove another one that does change color under braking and talking to the dealer on the phone they said the other 08's change color also.)
Anyone out there that does alot of highway driving (70% at 70-75mph) that could tell me what kind of MPG they are getting would be much appreciated.
Thank you all.
#488 of 998 Re: mileage [fluid_dude]
Jan 14, 2008 (8:55 am)
I don't do as much as you do but I put about 35K on mine annually. It too is about 70% highway but the max speed I'm allowed is aobut 65 most of the time.
Lifetime over 65000 miles I'm at 47.9 mpg....but here are the caveats....from a post that I made in the Camry hybrid forum last year here
Factors affecting your FE ( and everyone else's also, btw ) in decending order of importance...
1) Towing anything is a huge penalty possibly as much as a 50% reduction in FE
2) Lots of weight in the vehicle, passengers cargo etc. ( EPA tests are done empty ) deduct up to 20% from your 'Norm'
3) Short trips under 10 min - deduct 20% from your 'Norm'
4) Snow, Rain, sleet - deduct 15%
5) Strong head wind - deduct 10%
6) Cold weather - deduct 5 - 10%
7) High speed driving 0ver 70 mph - deduct 5 - 10%
8) Many starts from a dead stop ( going from stop sign to stop sign to stop sign ) - deduct 5 - 10%
9) Terrain - fortunately 'what goes up..' usually this balances out on a RT
10) Winter fuel - deduct 2 - 5%
11) Low tire pressure - ? How low
In your type of driving you probably won't run into a lot of these like many starts and stops and towing and short trips. But cold weather, wind and slippery surfaces will have a huge cumulative effect of as much as maybe 10-25% reduction from your best results. Pathstar1 who lives in CA would be able to give you a better perspective on these factors.
Afriend who posts here also is at 175,000+ in just over 4 yrs but in the Middle Atlantic region where it's milder. I believe that lifetime he's around 47 mpg also.
#489 of 998 Re: mileage [fluid_dude]
Jan 14, 2008 (12:44 pm)
I posted the URL for the "stages" in post 483 of this discussion.
Many Prius owners have posted they have only seen green bars after a few months. It -may- take the car that long to be sure of the full capacity of the battery, self calibration so to speak, or it -may- be (my choice) that the NiMH battery needs some charge/discharge before it begins to work fully. At any rate, I didn't see -any- green bars until 2 months after purchase. Usually you won't reach full green unless you descend a long hill, such as a mountain pass, though it is possible if you are really economical in the city. You won't see green on level highway, or at least I don't. The car tries to keep the SOC (state of charge) at about 60%, blue bars. I doubt there is anything wrong with your car.
Once the car is nice and warm, you can get up to 50 MPG on the highway, but that's a summer figure. The faster you go, the worse the mileage. You probably loose 2 MPG to the ethanol in the fuel, another 2 MPG to winter added friction (oil viscosity and stiffer tires). Then there is added loss from heavy winter winds, and snow pushing. Be aware there is a breakin period during which you will not achieve the good mileage figures. This includes breaking in the tires. It seems to take 2000 - 5000 mi. You should be able to achieve 45 MPG in the summer and 40 MPG in the winter with no problem, once broken in. Many do better with practice. The winter warm-up cycle is very hard on mileage. I notice that once my car is fully warm, in winter, it starts to get nearly the same mileage as it did in the summer, but the average really suffers. My summer average, once I learned and the car was broken in was getting up around 53 MPG US. Right now it's averaging around 40 MPG! City only in winter.
#490 of 998 Re: mileage [pathstar1]
Jan 15, 2008 (11:12 am)
I filled my tank (8 gallons) with 10% ethanol for the first time. Here in the flat SC low country, I average 53 mpg consistently. This time I averaged 50.5mpg with no change in route or driving technique. I then made it my business to fill the next tank with pure gasoline and I immediately saw my mpg go back to 53. Although 10% ethanol produces a 4% mileage penalty, the price at the pump is no lower than stations without ethanol diluted fuel. Considering the effect of ethanol production on the cost of grains and meat, and the impact of its production on the environment, I think the promotion of ethanol is a huge mistake.
#491 of 998 10% ethanol - real cost
Jan 15, 2008 (11:23 am)
You raise a good point. For me, the gas mileage is a sidebar to the cleaner emissions of the Prius, but use of ethanol shouldn't be pushed as good if it's more harmful in production!