are my short trips really killing my mileage?

YES, short trips kill your mileage! So does driving 75mph, VS driving 55-60mph. The Prius is a ingenious car, but not a miracle car. It has limitations that are agreeable with a conservative mentality. That is: Drive the speed limit. If the speed limit is 70-75mph then this will exceed the Prius conservative design and you will have to lower your speed. If you have ever been to Japan then you know that the stall and back-up traffic can be so intense that one may sit in the car and do 5mph for two hours. Compared to 80mph, the Prius does quite well in slow traffic. I believe that is what the car was designed around. :cheer2:

 

You should be able to do 70 and still get 45mpg though. You don't HAVE to clog up freeways driving like that.

 

Oh

I thought you could buy the Prius, drive it like it was stolen and still get 100 mpg. I have been misled and want my money back!

 

Use trip B to tell you what your little journeys are netting you.

For my 12mi trip I could pull about 44 or so in the morning and around 55 in the afternoon.

 

Stop using pulse and glide, start using cruise control when you can.

 

This is your mileage killer right here.

First and foremost: the Prius is a HYBRID car, not an ELECTRIC car. This means that (unless you've had a PHEV conversion done) all electricity going into the battery comes from the gas engine (ICE)--very inefficient. This includes any regen capture from going downhill...after all, the car had to get UP the hill in the first place, right?

Now using regen from the battery is not a bad thing, it helps increase mileage, but it's best to let the car decide when to use it...it's pretty smart!

EV mode is sometimes referred to as 'parking lot' mode. That's a pretty good label for it. Use it only if you want to do something like: back the car out of the garage to wash it; move from one spot in the parking lot to another on the other side, etc. DON'T use it to travel a couple of miles down the road...the battery doesn't hold that much 'juice' and you have to recharge it using the gas engine--a very inefficient process.

Bottom line: try driving the car like a non-Prius car, but drive it gently. Don't drive it like a granny, you'll just get people mad at you. Roll up to stoplights instead of going full speed 'til the last minute and braking hard.

 

Get a tire gauge for 5 or 10 bucks. You cannot trust that they were inflated properly or that they have not lost some pressure since filled. MINIMUM is the placard pressure on the door frame. For better mileage, increase toward the sidewall maximum pressure on the tire, keeping the fronts 2 psi above the rears due to extra weight up front.

Next, learn to glide and minimize use of the brake pedal consistent with not hitting anything or being a hazard.

These alone should get an 8 mile commute up near 50 mpg. Work on DWL, P&G, and other techniques for even better results. DWL is essentially driving with a constant throttle position rather than the constant speed of cruise control which is less efficient in hills.

See the links in my sig for more info.

 

I agree with MJFrog. The EV mode is likely tanking your MPG.

The A/C is also a killer on short trips. If the car is very hot inside and you simply turn on the A/C then drive, you could be losing 10mpg for the first few minutes until the car cools down. I've observed this in my own car.

Watch the scangauge on my dash. You'll see how mpg drops approx. 10mpg when I switch on the AC. When the car's interior is cool the mpg drop is only about 1mpg. To reduce the initial MPG drop either allow your car to air out before driving it with the AC on or drive with the windows down for awhile to cool down the interior. The MPG drop from the windows being down is less than using the AC to cool off a really hot interior.

 

Heres my low down:

- What fuel economy are you getting and how are you determining fuel economy? (trip computer or manual calculations) 39mpg, my calculations: how many gallons I filled up divided by miles driven
Isn't it miles divided by gallons pumped? 500miles/10 gallons=50miles per gallon.

- What fuel economy are you expecting and why? at least 40 something!
For your trip at least 40 sounds about right

- What are the approximate outside air temps? 80-90 lately
That's the perfect temperature for high MPG. It's warm enough for fast warm up. It's cool enough to use A/C in the low setting

- How long are your trips? I drive 8 miles to work, 7 on the freeway and trying to drive like a snail now, still doesnt seem to help!

Warming the engine at freeway speed uses more gas than warming the engine in the city streets. You could try leaving home 10 minutes early and drive 2-4 miles in the city streets before you hit the freeway.
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How old is your 12v battery? What is the voltage reading of your 12v battery after sitting over night? I dont know really, I got my car 1 year ago
If you have never let the 12v battery die, your battery should be in good condition.

Have you had your alignment checked? Any pulling or abnormal tire wear? no I just got my tires rotated and alignment checked etc. etc
New tires will decrease mileage until it's broken in.

- How much of it is city vs. highway? Roughly what's the average speed in overall and and of each segment? Is there a lot of stop and go driving? A mix between city and freeway, I would say half and half, and I dont even drive that much! Everythings reasonably close to me.
Take the streets instead of the freeway. There's a reason why the Prius gets better mileage on city streets than on freeway.

- What's the terrain like of your drives? (e.g. flat, gentle hills, steep hills, etc.) Hills in my area of Echo Park
I think hills is your poor mileage culprit, especially on the freeway.

- What are your tire pressures? not sure but I just got my tires rotated and I know they checked the pressure, just the standard pressure Im sure they put in.
If you got your service done at the dealer, then it's the recommended pressure.
- Is your oil overfilled? (i.e. above the full mark on the dipstick)
No

- Make, model, year, engine and transmission of previous car? (e.g. 08 Honda Civic Si 2.0L 4 cylinder, manual transmission) What did you actually get on the same trips/commute? (Please give us actual numbers, not EPA ratings.)

ford focus 2002, 30 mpg


- What region/state are you in? (if you haven't set your location) california

- How are you trying to drive (e.g. trying to stay in electric only?) and how hard are you braking? trying to do the whole pulse and glide thing, doesnt seem to help
When braking, never let the HSI go pass 100% of the CHG. Brake a little early if you have to. When you brake at less than 100% on the CHG bar, you're capturing 100% of the forward momentum energy into the battery and not using the brake pads to slow down the car. A high HV battery SOC means more electric assist when driving in blended mode therefore returns higher MPG.

- What modes are you using, if any? "normal", EV, power, eco? EV mode
Stay away from EV mode. Use EV mode if you're driving less than 1/4 miles like in the parking lots, moving from the streets to the garage. Never use EV mode on city streets. You'll use more gas recharging the HV battery later when you ran out of juice. I always drive in normal mode because you get a little better response when accelerating and cooler A/C without affecting the mileage too much.

- Are you "warming up" the ICE (internal combustion engine) by letting it idle after powering on? no actually I never do
I don't neither. The first 1/2 mile is powered by electric while the engine is warming up.

- Are you driving using D or B mode? d

- HVAC settings? Are you using the heater, AC, auto mode, etc.? If using auto, what temp is it set to? ac is on all the time on auto, i been trying to keep it in the mid 70s its been warm lately
This may be a bad advice but I've always set the A/C at low but at the lowest speed or at 2 bars.

- Are you using the factory tires and wheels? If not, please indicate tire make, model and size (e.g. Goodyear Assurance Fuel Max 185/65R15). factory tires since I got the car last year
15" rims and tires should get better mileage than 17's

- If reporting a mileage drop, did anything significant change on your car (e.g. accident, hit a curb or big pothole throwing off alignment, oil change/other maintenance/repairs, changed tires or wheels, etc.) or your commute? No not really

My commute has changed now that Im closer to work, I use to drive 40 miles to and from work but now only 8miles. 7 of which are on the freeway, and Im trying to drive super slow. I only work 3-4 days a week so I dont put a lot of wear and tear right now on my car.
On days off Ill drive to my moms house but shes only 12 miles away on the freeway, once again going like a snail right now. I pick up my husband at work maybe 2-3 times a week, but that too is only about 4 miles .
I mean realistically it would be ideal to bus it around town but I work at night so I cant, and lots of places in LA are not that easily accesible by bus hence why you have to drive just a few miles, and its been hot so thats why we drive.
I dont know if all those short trips are why Im getting such low mileage, but that seems REALLY low..or is that normal and fair? I
always get my tires rotated and oil changes at Toyota dealer so theyre doing what is standard I would assume.
Also, when I went to SF last month my mileage sucked then too, about 38-39, and that was going the speed limit which is higher at 70, maybe 75!!
To be honest I never noticed what my mileage was before I started working so close, I didnt calculate it but I did get about 400m before my empty light went out, which I thought was ok, now its not even close.

Thanks for your help!


The Prius cools very fast. If you let it set for an hour or 2, you'll have to start the warming up cycle again and that lowers your MPG. Try to combine all your errands to at least 10 miles and drive on the street as much as possible. When you brake, you're not using fuel. When you stop at a stop light you're not burning fuel. You don't have to drive like a snail but not bat out of hell neither.

 

To answer the question in the topic, in a word, Yes.

Well you can try this. I'm not saying it's going to work, but it's worth trying:

Don't drive like a snail during warm up. Drive normally because your car wants to warm up. Driving slow is not going to warm up your car faster.

 

I doubt Toyota will fill the tire pressure beyond the recommended pressure. You have to fill it yourself to 40psi.

 

Ohhh, just to chime in on top of everything else that has been said, really could be the terrain, never know. Even with "hypermiling" sometimes there's nothing you can do. I mean, you can see my average mileage in my signature...well, if my work was in the other direction, it'd probably be in the 40 mpgs! If I drive 7 miles on the highway in one particular direction from home it'd be around 40 mpg, just happens to be quite hilly that way, and that's driving the speed limit!

 

Some time when the car is warmed up, get out on a somewhat flat road and reset trip B, then see if you get mid-50's or better at 60 mph (dry road, no big headwind, etc.). There is always the chance something is causing your car to use extra fuel. Doubt it though. Your results are "normal," but you can improve them.

Everyone with tires needs a tire gauge. Toyota not likely to put psi where you need it, but you can do it at a gas station or a friend's house, or buy a portable inflator.

 

The question is:What is great mileage??? When I went to a Peugeot and then a VW 1300, I thought I was getting great mileage: 25-35 mpg! neither car is designed for 100mph. This goes for the Prius too. I would consider 40-45MPG great overall mileage! At a sustained 100MPH the car probably would get great mileage as it would be impounded in the Highway Patrol lot for "BAD CARS" The main problem is mileage greed, ie: always wanting better mpg and confusing highway trip mileage with other types of city driving. I aim for 50mpg, I do not always get it. Going to LV awhile back I showed 69 mpg, thats because the wind seems to whip off the LA region and head straight for LV. I probably had a 60 MPH tail wind. A good philosophy is expect less and get more.

 

Two comments:

1) I drove in ECO mode for nearly the first 2 years, then switched to "normal" mode after somebody here posted that doing so increased their MPG. Mine has also gone up slightly since disabling ECO.

2) Get yourself a tire gauge, and check your tires monthly. I wouldn't trust that a dealer set them to the correct cold PSI level, plus tires do lose pressure over time. I have mine set at the pressures called for on the B-pillar sticker (I tried increasing by 5 PSI for a while, but the decrease in ride quality wasn't worth it), and have a lifetime average of 45 MPG (and I don't hypermile).

 

Did you eliminate the possibility that your MPG increased is due to the engine breaking in and reduced rolling diameter and rolling resistance of your tires as they wear down?

 

i used to live by you, now i live by baldwin hills.. so.. i'm not reading any above (dangerous, i know) and directly replying.

it's the city.. it's robbing your mileage. between the long stupid wait times at all these crappy lights in this city that should be all in sync... warm up cycles that you can't really get up to a constant speed on... and the hills.. yeah... LA is pretty flat.. but not really.. it's all hills. dumb little rolling hills...

everyone on here loves pulse and glide... it's annoying in a big city like this.. you're going to stress yourself more by trying to pulse and glide than if you were to just drive it... plus... trying to push this car into certain limits tends to blow up in most peoples faces.. either you're annoying on the road or you're burning up too much electricity which negates the entire attempt.

in my 04... i do semi jackrabbit starts... have aftermarket tires... and stealth when i can. i tend to not hug people in front of me and leave a gap so i don't have to participate in stop and go traffic.. the difference between a full stop in traffic and coasting through the stop while in traffic is HUGE in terms of power consumption.

keep the a/c at about 76 or so when you first turn it on... roll down those windows to do an air exchange.

non highway, i turn my a/c off because there are too many lights in this city. it's the 45mph rule.. above it, use a/c.. below it, use windows... unless it's too warm.. then start the a/c off at the temp i said an eventually lower it down to 73 or so (any colder and you're fighting an uphill battle)

i've heard a lot of good things about pwr mode... something about it being close to the "just drive it" standard... instead of you trying to figure out what the car should do.. it simply does.

 

Given that I disabled ECO after 2 years, I would think the break in period was well over. Regarding the tires question, the increase was evident immediately.