Colder weather has zapped my mileage to 44mpg

Your results seem about right. Winter is a bear. Try grill blocking for faster warmup and better heat retention.

 

See the winter survival guide for hybrid owners over at cleammpg, also.

 

Excuse me for being blunt, but the definition of "colder" coming from someone in Texas makes this Minnesotan quite curious.

I'm half way through my first tank of sub-freezing temperatures. That's just the first taste of winter here. The averaged displayed is 51.4 MPG with the lower-grille 100% blocked, tires at 44/42, using E10 for fuel, and staying in ECO mode most of the time. MPG like that makes this previous generation Prius owner very happy. Next month when sub-zero temperatures become routine is the real test though.

My suggestion is switching to ECO and leaving it there with the only exception of PWR use when an aggressive turn/accel is needed. You'll be impressed by how clever the ECO mode is. We're discovering Toyota actually delivered more than they told us about.
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To my limited knowledge and experience with the Prius, it seems that wet weather has a bigger influence on the FE than colder temps. Even in 15 degree weather I was able to get 60 mpg + on my 18 mile commute into work the other day. It was dry. When it was wet/slushy I would be lucky to get 50 on the same leg.

I am currently tracking the FE and temp on the two legs of my commute. After I get enough data points I will plot and post.

 

Forgot to mention... you're basically up-a-creek when it comes to the MPG hit caused by winter-formula fuel. So, even with the benefit of the stuff you do have control over, there's always going to be a penalty from that.
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MPG's continue to drop. Right now the average is about 40 MPG's with the sudden drop of overnight temps in the high 20's.

Its sure had to believe the flucuations in MPG. Like I stated before my 2003 VW Jetta Wagon TDI (diesel) 5 speed manual, never, ever flucuates like the Prius. MPG average is about 54 in summer and 51-52 in winter.

Our Prius has the most fuel efficient tires I know of, Michelin AS Energy tires with 44 PSI (nitrogen) in all four.

The oil is Mobil 1 0X20 with 4 quarts in the crankcase so it is not over full.

So everything is set up for MAX MPG's.

Does anyone else out there getting this big a drop in MPG's?

alfon

 

If Prius was allowed to be as dirty as the Jetta (T2B5 rating) rather then PZEV, it too would be impacted less by the cold. Sorry, but that's the reality of emission cleansing.

This is the 5.5 years of data summarized from my previous Prius...



Already, I'm seeing less of a cold temperature impact with the 2010. But it's still way to early to quantify the difference yet.
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Nice graph... and very indicative of what I am seeing now in my 2010.

 

I am in MN and my mileage since it has gotten colder (~20-30 degrees) has dropped markedly during my short drive to work. I cannot get into the 40mpg range at all.

I seem to be only 44-45 at my best city or road driving. Am I doing something wrong or is something wrong with the car.
I have a 2010 V.
Thanks

 

You're consuming more fuel for heater other than driving Prius.

Ken@Japan

 

In your case you have a double whammy; cold weather and a short drive (BTW, what is the distance?). If < 5 miles, you car is probably warming up in its least efficient phase/stage. The longer the distance, the more your able to make up the loss (averaging). Is your car garaged? If not you might invest in an engine block heater and grill blocking. Also keeping the car in ECO mode with lower cab temp if you can stand it.

 

Thanks for all the input.

I only have 3 miles to drive. I have been keeping the heat higher; I will keep it lower--it doesnt even warm up in the few minutes it takes to drive home. The car is garaged. I drive in nothing but ECO mode. Should it make any difference that I use the seat warmer?

 

Where is that site please?

 

Ouch, yah that is a tough one. If fact before I really knew anything about a hybrid, I figured short, in the city types trips is where they would excel. But that is just not the case. EVs have that covered.

As far as the seat warmer... that fact is that is uses power from traction battery and the engine is essentially the only way that battery gets recharged. So it would have an impact but in your situation probably not a big one.

You might read up on the Pulse and Glide method... that might help you squeeze a few more MPGs.

 

I would definately kill the heat if you are only driving 3 minutes. You will see a difference.

 

A typical seat warmer uses 12V power, and the seat warmer is more efficient than climate control on a short trip.
If I were a peeson driving 3 mile commute, I even don't use any heater.
I can be patient for the short several minutes driving.

I bet the Pulse and Glide method does not work on 3 mile commute in a cold weather.
The engine continues to run for warming up.

Ken@Japan

 

You are probably right as you know much more than I. But I figure if he is coming out of a warm garage and is in ECO mode, perhaps the ICE would shutdown during the glide after a bit.

 

I'm starting to have a tough time. When I first rode car home I got 63 mpg. I thought maybe it was my focus that I losing. But people here are talking wheather change , I live in Monterey Ca. I'm getting between 44 and 48 mpg now with 10,000 miles on car. I'll try to see the difference when wheather changes. We have a mild climate here do u think I need a grill blocker?