Newbie Questions - Prius Fuel Economy for Dummies?

I wouldn't be surprised about low mpg's on the first few hundred miles, but if you get to the trip A or B indicator is does show the computer calucated mpg's which many find around 2 mpg's better than you actually get. Also I'm not convinced the dealer "Filled the Tank" as you or I would. Yes it says full but really did they top it off?

 

:welcome:, glad you joined us.

You will need to make sure after the first tank that it is filled up properly. I set the handle on the first notch, set it again after it automatically trips and remove when it trips the second time. Make sure to clear one of the trip meters at this time.

The scratches are a problem. The material is very soft and easy to mar. I don't believe anyone has found a full proof method to remove them.

Enjoy the ride!

 

130miles is very low for a half-tank (even though a half-tank on the gauge is only 5 gallons). That's something like 26mpg, which is way low for a Prius, even in cold weather and adverse driving conditions.

So - possibly the tank wasn't full to start with, possibly it's still breaking in, possibly it's not really at a half-tank yet (possibly it has been more than 130 miles?)

First I would top it off yourself and reset one of the trip meters to establish a proper baseline.
Next I would check the tire pressures - need at least 35 psi front, 33psi rear. Just one tire well below proper inflation (especially one of the fronts) would have a major impact on mpg.
Last, I would wear a proper coat and not jack the heater too much - if you have a long stop&go drive and keep the heater >70F, the engine will have to run just to keep you warm. Moving nowhere (or very slowly) with the engine idling is pretty bad for mileage.

If you're not too married to the idea of keeping one tripmeter as your "lifetime" meter, you could use Trip A for the tank, and reset Trip B each leg of your commute so you can see what the mpg is in the morning vs on the return leg. This may provide a clue where you're losing the most.

Also check the grill blocking thread in the mods forum - I don't think it helps mpg much, but it seems to help with cabin heat which might be a bigger factor for your stop&go drives.

 

Hi fellow n00b! I also picked up my Prius this past saturday.

Good info from the other posts!

I have shown off my Prius to friends and while sitting parked with the car and heater on, my gas milege drops very quickly. If you are sitting in traffic with the heater on you may see your mpg go quite low. It's cold here as well and I keep the blower set low and the temp set at about 69 or 70 after running it full blast for a couple minutes to initially warm up. I like it cold though!

The best way I found to get used to all the displays is to just drive around a big empty parking lot. I did that for a while and got used to the sheer amount of information you can get. Made it much easier to absorb that information on the road. Almost like learning on the job!

I've settled into using my Trip A for daily MGP reports driving to and from work. I reset it each morning. I will use Trip B for each tank.

Good luck!

 

If you want to keep a lifetime MPG you could use one of the web based fuel logging sites like fuelly.com

I use one trip meter for the tank and the other for the trip and fuelly.com for the cumulative history.

 

Yep, and a spreadsheet works too - you just have to be sure not to create any gaps in the data.

To get the worst possible mileage in the Prius, start the car but stay in Park, reset the tripmeter, then turn on the heater full-blast along with both front and rear defrost. Headlights and wipers will add a tiny bit also.

Sit there for about 5 minutes or until the defrosters shut off, then drive 1/10th of a mile to give the meter some distance to factor in (it will read 0 until it has some distance to calculate with).

I haven't done this, but would expect it to be some decimal under 1mpg.

Which leads to this observation: it's best to start with the heat off (or in "auto" with a temp of 68F or less) and get moving before cranking things up. The mileage penalty will always be worse when the distance is smaller (given the way division/multiplication works).

Also: try ECO mode for your stop&go leg, it tends to be more aggressive about engine shutdown when stopped, so there should be less idling (and better mileage).

 

I would bet the tank wasn't full. I have only had my Prius for a week and I wondered what the mileage would be but I waited until the first bar plus had dropped off the fuel gauge - no reason, just wasn't thinking clearly. The mileage was low. I then reset the odometer and waited until the first bar sometimes dropped off. That showed 45 mpg, which given the many short drives I need to make and how cold it is and that I haven't checked the tire inflation, is fine. The tank was clearly not full when I got it.

 

Tara, welcome. The MID (IMO Mis-Information Display) takes some getting used to. The car's calculations are optimistic but can be used as a rough guide. I'd run the first tank down to 1 or 2 pips then fill up. I keep track of lifetime FE on a spreadsheet & use trip A for the tank.

Blocking the grill retains heat so the ICE doesn't run as much. Inflating the tires to max. sidewall pressure increases tire life, decreases rolling resistance, and increases traction on wet pavement. I keep the heat off for the 1st 5 minutes as the car needs it more than I do. Climate Control is manual at 74F with fan speed at 2 bars.

Crawling or parked in traffic kills FE especially if you need to run the heat. Experiment between ECO & normal modes.

Plugging in a ScanGauge will provide more information to enable you to improve performance.

Unless you tried topping off the tank you don't know how full the car was. As long as the tanks keep improving things are OK.

 

I tried higher tire pressures today - went from 37/35 to 41.5/39.5 (wasn't shooting for .5, it just worked out that way). These are my snow tires, so they're soft to begin with, but they're rated for 44psi (cold), so I felt pretty safe with those levels.

Big difference, as far as I can tell so far - it may be a bit more than 3mpg, and it seems to apply equally to "around town" and highway speeds.

My gauge this morning (with the tires at the lower pressure) was staying right around 45mpg displayed (42.4mpg actual when I filled up on the way home), this was from "around town driving" and some playing around with P&G, albeit in somewhat colder temps (low 20's F). 47mpg displayed is a little more normal for temps near freezing like today.

I was at home long enough for the tires to cool all the way down (the engine didn't get all the way cold but fairly close), so I pumped them up to 41.5/39.5 and went for a little test-drive later in the day. Display easily went to 50mpg and stayed right around there for "around town" driving, so I made one brief stop at a store then hit the highway for about 18 miles mostly at 70mph. I used Trip A for the highway test, it settled in around 46.7mpg displayed by the end - I have seen as low as 41mpg displayed for highway on an especially cold trip (high teens F).

So my guesstimate is about 3mpg difference with not quite 5psi more in the tires - won't know for sure until I have more miles in colder temps, but it's definitely at least 2mpg (4-5%).

 

I too just got a Prius. Just wondering how much I should expect the fuel efficiency to drop as I drive above 60 MPH? I realize the fuel rating is better in city. I chose the Prius over the Jetta for fuel efficiency - my communte is about 35 miles of highway travel in each direction daily. Any thoughts?

 

Here is one of many bobwilson4web charts available in this forum, this one copied from this thread:
http://priuschat.com/forums/gen-iii...41-new-prius-only-averaging-38-mpgs-help.html


60 at 60 is holy grail ideal conditions, IMHO. Cold weather will be lower.


http://hiwaay.net/~bzwilson/prius/pri_2010_800.jpg

 

I would just like to add that I have found that the first bar drops only after 80-90 miles so you easily could have been 1, 1.5 or even 2 gallons less then full which really would explain you getting the mileage you thought.
I am still getting 35-38 now thru 4 tanks.
I must have to do with my poor commute to work.
I also notice that even a very slight slope can hurt mileage a lot and visa versa.
Recently started using the 1 min MPG display regularly (together with the windshield bar).
I find it interesting to follow.

 

Hi Vday

I also use the Hybrid System Indicator bar in the HUD and the 1min mpg display on the dash display, and find this is a great set up for getting the best economy.

Hi Tara 1031

Stick with it, you'll get the mileage up with experience. I find that you have got to really back off the accelerator to get the best economy and it is a very fine line between getting 50mpg and 60 mpg. Using ECO mode does help get you used to the system. I have also found that cold starts and short journeys can really kill your economy. Say I've done 300 miles in a day at 65 mpg average and then I do two or three short journeys from cold, on my day off, I find the economy will seriously drop to about 50 mpg average. Add a cold morning where the heater is being used and this really knocks the economy further, as does leaving the car to warm up.

I do still love the Prius and the economy I get. Presently I am on track to a projected saving of £3000 ($4500) per year from my last vehicle. That is on UK petrol/gas costs but is still one big saving and will almost pay for the car. Almost a new car for free!

 

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When I picked up my car the salesman helped us setup the Bluetooth for our cell phones, I noticed and told him that "someone forgot to fill the gas tank". He apologized and said he'd follow us to a nearby station that they use and he would top it up for me. He did exactly what I expected, which was at the first "off click" of the pump he pulled the hose, so I knew right then I didn't get a "full tank". And this is what anyone should expect..... it's not their car. I am happy with my dealer, and I think this is just what any "employee" of any dealership would do. If you came back complaining of FE after that first tank all they would do is tell you to do is put many more tankfuls through the car before you draw any conclusions.
Also these tanks are small, (10 gallon?). My Camry, 4cyl., can go as far as the Prius on a tankful. But that is decieving because when I fill the Camry up it takes close to 19 gallon from near empty, and a lot more $. So have to think about such things. Ford advertises that the Fusion hybrid can go soooo far on a tankful..... well there's a reason, larger tank, not better FE!

 

Do not stress about mileage at first, you need to be learning how the car works, so just drive it. Once you have three to four tanks experience, time to start adapting the way you drive to what the Prius likes.

But for safety's sake, be learning the car now, worry about mileage when you are comfortable.

 

I actually observed the bars on the fuel gauge go up one notch on several occasions before continuing to go down. The small tanks must make the float sensor very sensitive.

 

We got our Gen III Prius in December and have made a few observations that may explain your experience. We have mild winters in So. California, so our mileage was 50+ from day one. This difference may contribute to slightly different results for you, compared to our experience.

After driving our Prius for about 3K miles, we have discovered that the gas gauge reads full for the first 3 gallons. Dealers are supposed to include a full tank of gas with the purchase of a new Toyota, but sadly, some cut corners to make a few extra bucks. I believe that our dealer short-filled our tank by about 3 gallons, presumedly to pocket an extra $10 per car. Our gas gauge went from the low side of full, when we picked her up, to half a tank in about 150 miles, on the first (dealer filled) tank, while the fuel consumption indicator reported that we were averaging 54 MPG. We have continued to average between 52 and 59 MPG on the display for every tank and have confirmed that our fuel gauge reads full for about 150 miles after our refills to the top of the tank. I believe that you will go about 150 miles further on your next tank, when you fill the tank because I believe that your dealer ripped you off for about 3 gallons of gas.

I don't know whether this deceptive practice of short-filling the tank comes from the salesman, service guys, or the dealer, but this is the kind of petty rip-off that gives car dealers a bad reputation. Although I have no way to know for certain, I have seen other posts on this site, like yours, that make me believe that this $10 theft is widespread. Other than politics, I haven't seen this kind of petty dishonesty since I was in junior high school.

Congratulations, I hope you enjoy your new Prius as much as we enjoy ours.