Prius mileage troubles

He is certainly correct that a deep freeze as we are currently seeing in the Midwest (Chicago area here) will affect my mileage by as many as 10 mph. This is true among other reasons, because the engine will remain on a lot more to continue to heat the interior. Sometimes I notice the engine running even when stopped at red lights, until I turn off the heater.

For me, I am averaging about 58-63 mph in the warmer 9 months of the year, and between 45-55 in the coldest three months. I am driving a 2010 Prius V and now have 47k miles.

For many people, 48 is a respectable number to get in the Prius. Certainly not hypermiling, but please remember that in order to get the really high numbers, you will be driving a lot slower than you are used to (at least off the line).

 

There is a questionnaire on here somewhere about fuel economy. Search for it and post to the thread. We might be able to help you out and get a few more mpg.

 

Mileage does drop as the temperature drops, but being as your mileage has never been better than 48 mpg, I suspect there are other factors in play.

My wife complains that she can't get better than 21 mpg from her CR-V. I took it today, topped off the tank on my way to work and ended up getting 25 mpg on my round trip. When I first got the Prius, I was getting 56 mpg (per the gauge) and my wife took it to do some running around. When she got back, the mpg displayed on the gauge was 48 mpg! But she doesn't think she has a heavy foot! I just tell her the numbers speak for themselves... You may want to swap vehicles with a significant other (if there's one available) and see if a different drive makes a difference. You may not think you have a heavy foot either, but sometimes it's hard to objectively access your own driving style...

 

It's been my experience that most complaints about low MPG (excluding first tank from the dealer) is due to short commutes. The first 5 minutes you may only get 25-35 mpg, and then it shoots up. So if you only drive 7-10 minutes on a commute, your mileage is completely expected.

That said, you can improve things somewhat, there's a lot of information here in PriusChat on that. Answer the questionnaire spiderman pointed out and we should be able to help.

 

Back last year when the temps were unusually cold in the
northwest, temps as low as 13 F, we got as low at 40 MPG, as
my wife would make several short trips to school to drop off
our son and go to the store etc.

During the summer our MPG's were as high as 58 MPG on a few trips, usually never below 50 MPG's calculated, not computer generated.

alfon

 

You're driving a "V", which I think gets a few MPG less than my II (at least here in the 'real' world) and I suspect your 39 MPG is about right---up there in frozen Albany and for your driving style.
If you're really REALLY worried about mileage, you're going to have to adjust some of your driving habbits, and maybe tweak some things in your car (tire pressures, heater useage, etc...) otherwise you're going to have to 'settle' for the mileage that you're getting now. Almost 40-mpg isn't exactly bad for a "mid-sized" sedan.
It does not sound like there's anything 'wrong' with your car, which is good news. You can boost your mileages a bit with a few modest changes, and you don't have to resort to all of the zany antics that the hypermilers get into.
I drive somewhat normally (speed limit +5, no P&G, no grill blocking or tire over inflation, etc...) and I get 50-55 in my II. Granted...it's about 15-degrees warmer here on average.
BUT... I don't 'rabbit' at stop lights, and I set my heater at 65, and I do drive in the ECO band of the HSI almost all of the time.
Is all of this worth 10-MPG to you?
Maybe.
That's a question for each driver to answer for themselves, and I'm not ABOUT to lecture anyone for being 'fuelish'.
It's stupid, it's almost always hypocritical, and I'm one of the few people that I know that drives a 55 MPG car, and a 30 MPG motorcycle....

 

Actually my motorcycle gets around 40-45 MPG. =P

To the OP, I am experiencing the exact same thing. However I am getting double hit because of the temperature AND my short commute. I am going to wait to see when the weather warms up and then check out my average again.

 

Unless you live in Los Angeles where there's basically no weather year round, you should expect some mpg hit at this time of the year.

 

Ditto here in the UK, my commute is only 3 miles/10 mins, I was getting nearly 60 mp(uk)g in summer and now just under 40MP(uk)g, 33%/20mpg drop, double whammy ! cold weather and short journey.
I probably would have done a bit better if I had bought some de-icer and not had to run the demisters to melt the ice for 10-15 mins before setting off first thing in the am.

 

10% loss for the winter gas you're using.

do the math. it's worse with a higher mileage vehicle.

don't worry though. all vehicles suffer the loss when the 10% ethanol is added

 

Your mileage is pretty standard for the weather we are having right now. Don't use the "auto" mode for the heater...it will use more gas. You don't have to freeze either, but use a manual mode where YOU decide how the ICE runs. Run the defroster (front & rear) only while it's needed, these use amps from the traction battery that must be replaced by the ICE generator.
It's a great automobile, only much different that anything we have driven before. Enjoy your new ride !!!!!!!

 

Yea, that's pretty much where I am.

 

Additionally, you must keep in mind that a 10%-15% drop in avg. MPG appears larger with high MPG cars than low MPG cars. For example, a 15% drop in MPG for a 48mpg car will result in a 40.8mpg avg.. The same 15% drop on a 20mpg car will result in a 17mpg avg.. Most people would never notice the 3mpg difference in MPG unless they actually tracked how much they spent in gas during that change. Because the Prius has a nice big display that screams you've lost 7.2MPG, we tend to freak out.

1,000miles / 20mpg = 50ga x $3/ga = $150.00
1,000miles / 17mpg = 58.82ga x $3/ga = $176.47
The net difference is $26.47 for the 3mpg loss over 1,000miles
or

1,000miles /48mpg = 20.83ga x $3/ga =$62.50
1,000miles /40.8mpg 24.51ga x $3/ga = $73.53
The net difference is $11.03 for a 7.2mpg loss over 1,000miles

 

To the OP:

The weather actually warmed up the past few days, and on top of changing my driving style a little bit (keeping the gauge in the middle as much as possible) my MPG jumped up 6. So the weather definitely had a big impact on it.

 

My mileage took a big hit this winter even in the moderate Willamette Valley in Oregon. I drive for good mileage, and averaged 50 this summer (hand calculated). I got the car 13 months ago, have 10,500 miles on it. Got 43 mpg last tank (calculated). Last year I drove the 30 mile round-trip to town twice a week for physical therapy--got better mileage. This year stay nearer home--trip to store is 5 miles round trip and weather in the 40's. Mileage really dropped. In summer I let the car warm up because it is fast--takes too long in cold weather! Add the minimal heat I use, and both defrosters when needed and mileage sucks! Rain, puddles on the road, and wind make A LOT of difference! Love my Prius--even 43 mpg beats the heck out of the 21 mpg I got on my Outback in the winter.