New Prius only Averaging 38 MPGs...help

I am a new Prius IV owner of just less than a week. I have been doing lots of reading on PriusChat (and thank you all for the great tips). However, no matter how careful I am to follow the tips I see on here, I only average 38 MPG. I know there is a period needed to break-in the vehicle, but my MPGs seem out of the normal range of low.

I'm driving the vehicle in the moderate temperatures of the San Diego area. My daily drive is about 20 to work on city streets of 50mph with very gentle starts and stops. I'm assuming its me and my car's not a dud. Any suggestions to improve my mileage? I have to go back to the dealer in 2 days. Anything I should ask them specifically?

Did you fill the car after purchasing it and reset the MPG guage?

Hasn't it been raining in SD?

The tank was full from the dealership and I did reset the the gauge. This is only the 1st day of rain. My other driving days it's been mid 60s and sunny.

Ok good deal.

Could you describe the tips you have been using? i.e. tire pressure, low speed driving etc.

I'm not good at all the Prius technology talk, but I've been trying a few things. Oh and I don't use the A/C:
1) Doing most of my driving in eco mode, using pwr mode to merge into highway traffic. 2) Anticipating stops and braking gently. 3) Testing EV mode in crowded parking lots 4)Gliding as much as possible (haven't experimented with the full pulse and glide technique very much) 5) Slow, gentle accelerations from stop lights. 6) The past two days I've stayed in normal mode, but didn't since much difference.

Basically I've been driving looking at HSI display and most of my driving is done in the low/mid range of the "eco area", but I do my best to glide and maintain in the "hybrid eco area" whenever possible. I try to avoid the PWR area whenever I can. I haven't checked the tires yet, but I read it's recommended to keep the front tires at 42 psi and the rear tires at 40 psi. I will check on that in the morning.

Trip length in miles and time? Terrain? Is it flat or hilly? Can you give a rough estimate as to how many times you have to stop?

As for "slow, gentle accelerations", are you trying to accelerate w/EV only? If so, that's not the best way from an efficiency point of view.

Are you using the heater and/or auto mode? If the latter, what's the temp set at on the HVAC system?

First of all, welcome and congrats on your Prius! It sounds like you're doing the right things, the dealer usually sets the tire pressure at 35psi so pumping that up will help. Every one has a different set of conditions on their commute... hills, traffic, etc., but you should be seeing better mpg's from what you describe. There is a period where you learn the sweet spots for optimum mileage as well as breaking the car in, so don't panic yet!

How much effect do rain and wind have on MPG? My MPG has been in the low 50s. But in the moring, it was pouring rain, my MPG was in the mid-40s. Took me the rest of the day (has been driving around all day) to bring it back to 50.

If you have a road that is fairly flat, at least 10 miles long, and free from stops, you could run some benchmarks. Looking at Google Map, perhaps a loop involving I-5 and I-805 and a pair of connectors might work. The key is being able to maintain a constant, cruise control speed. The protocol is:

• practice loop - using the target speed, run the route to check for any traffic or road construction problems ... clearing the loop ... and trim the cruise control to get the test speed.
• reset "B" or "A" tripmeter at start
• record data after loop - the idea is to get:
  • miles
  • MPG
  • avg speed = cruise control speed
• adjust cruise control +5 or -5 mph - for a second point
• repeat test

We don't have a loop in my area so I used two runs of 10 miles each way and averaged the results to generate this 'mph vs MPG' chart:

I gathered this data on the drive home after picking up the new Prius.

Bob Wilson

Hi eamers, everything needs to be perfect for good or great FE in the Prius. Consider the following adverse factors and think about each one of them adding a 1-2 MPG drop. Do the math and see what they can do when combined...

- Low temperatures (the drop here is a lot more than just 1-2 MPG).
- High speed (anything above 60-65 is too fast for Prius FE)
- Terrain inclinations
- Rain, snow, or simply wet roads
- Wind
- Short trips
- "normal" tire pressure (consider overinflating your tires and a rougher ride)
- Weight (have you ride your Prius with 4 adults on it? Ain't pretty...)
- Stops along the way
- Poor driving habits
- What esle?

Don't feel bad! On our first fillup two weeks ago, our MPG was only 28!! Next tank was in the high 30's and yesterday (our third tank) was around 44 MPG. Winter was always a bad time to check gas mileage on our G2 Prius and I think it will be the same on our new G3. Things will improve.

Im having the same prob. However,its cold in NYC & I only had it for a month(the III,2010). Don't drive it often but reseting the gage is something I will try today

Perhaps a heretical suggestion, but as a new owner you may be better served to stop thinking about mileage. Forget that you have a Prius, and forget that there are techniques for getting better mileage. Just go out and drive it like you would any other car.

After a few tankfuls of "normal" driving you will have a baseline. After that you can try some tricks.

Many new owners over-think the whole driving process and end up making things worse. Ease up and let the car do its thing.

Tom

Good advice. I agree....

I'm a member of the sub-40 club, too. But I attribute that to my terrain and heavy interstate (70 mph) use.

If ym home ever sells, I'll be moving to a less hilly area with a suburban commute, hopefully greater FE.

Thanks, I was actually thinking the same thing yesterday. I really appreciate all the responses and suggestions though! My car is at the dealership now getting some things installed and I did ask them to check any factors that could affect the MPGs, but when I get it back I'm going to just drive normal for a bit. Tom, I like the idea of getting a base, and learning how I can improve from there.

You all are so helpful. I love being part of the Prius family. :cheer2:

I get about 52MPG a tank. I used HSI screen all the time and easy on the gas from 0. Getting on the freeway try not go in to PWR mode (I know is hard) after it reach the speed you wanted (mine about 65MPH) hold your gas the same position and monitor your MPG gage (next to your speed meter) It should be around 50MPG.

Please do provide more info as I and others have requested. Also, it would be super helpful to provide what actual mileage you got on your previous car over the same commute and comparable weather. Please specify make, model, year, transmission and engine (if there are multiple choices).

All of these affect non-hybrids too.

It seems that high-fuel economy hybrid owners (Prius, HCH, Insight, etc.) seem to scrutinize the fuel economy more and tend to track it. A given percentage change might look large in absolute mpgs and not so large if the base # is small. Consider a 10% drop from 50 mpg == 45 mpg -> 5 mpg loss. 10% drop of 20 mpg takes you to 18 mpg -> 2 mpg loss.

Would people on my350z.com even notice or make a big deal about a drop from 20 mpg to 18 mpg? Not likely. How many there actually bother or care? Few, if you ask me.

Contrast that with a 5 mpg drop on a Prius.

I couldn't even get my mom to bother tracking her gas mileage on her 96 Camry V6. Her attitude was "why? It's going to get what it's going to get." She couldn't care less (it seemed) about it signaling a change in driving habits, car probs, underinflated tires, etc.

It got totaled after someone rear ended her and was replaced w/an Altima Hybrid. At the beginning, she remarked once that it "seemed to use a lot of gas" by movement of the gas gauge. I ask "how do you know?" and said "you didn't bother tracking the #s on your previous car. How can you compare?" Well, she still can't be bothered to track the mileage or even reset its trip computer between each tank.

I can see its trip computer reporting in the mid to low 30s for mpg but beats me if it's accurate.

My dad can't be bothered w/tracking his mileage on his 02 RAV4 either.

Funny how that seems to change when gas goes over $4/gallon.

(Of course, then it's Washington's fault...)