I always had high averages with my '11 ES350. It actually did extremely well on the highway and my combined city/highway mileage was always in the very high 20s (probably a 70/30 mix of city/highway driving). The '13/'14 will perform even better and with a lot of highway mileage, 34 mpg average would not be difficult.

 

I purchased my ES300h at the end of April and am also having the experience of my mileage suddenly going down by about 5 or 6 mpg as the weather in Minnesota gets cooler (still not cold by MN standards), so you are not alone. It is disappointing but I guess just another reason to spend more of the winter down south. I also observed on one trip of several hundred miles that I got much better mileage when I did not use the cruise control (letting the car slow down a bit going uphill and letting it speed up a bit on its own going downhill). It made a difference of about 5 mpg but I don't know for sure if the amount of uphill/downhill driving was the same for both the first half of the trip and the last half, although it could not have been much different. Has anyone else experienced better mileage with cruise control off?

 

With every vehicle that I've owned, using cruise control has caused mpg to take a hit.

 

Yes, the cruise control affects your mpg especially with the 300h. What you're doing improves FE during warm or cold weather.

 

Adding to what I said above, I think that what happens is that, when you are using cruise control, in order to maintain a constant speed when you are going up or down grade, the gearing is changing to lower ratios more often than it would do if you otherwise allowed speed to vary a bit when ascending or descending. Whenever, that happens, the result is that mpg goes down.

 

yes, the cruise control negates the fuel savings of "coasting"

 

There is no way of knowing for sure what the impact is of using the cruise control unless someone was to do a scientific study. Overall, it is my guess that using it it helps most people get better fuel economy much of the time. I use it often and have not noticed any reduction in my fuel economy over the course of a tank of gas.

I don't believe you loose much in the way of efficiently when grades/hills are involved, with or without the cruise control. What you loose going up a grade/hill, you gain [most of it] back going down.

 

I guess one of the advantages of living on the California Central Coast is that the temperature range most of the year is between 60 and 70. So I rarely see a drop or increase in mpg (over Thanksgiving I averaged 41 mph driving freeway for 300 miles - but mostly around my house I get around 38 mpg).

 

As others have said, the culprit is winter. Winter blended fuels, but mostly its temperature. Hybrids are much more sensitive to changes in temperature and heater use than gas engines. if you look at the Prius forums they actually will stuff their grilles with pool noodles and pipe insulation to combat the effects of cold weather on fuel economy.

When we had our Prius we got probably 20% less fuel economy in the winter. When you realize that in the summer we got 45MPG, we're talking a drop of almost 10MPG.

For most drivers hybrid or not cruise provides a steady throttle input, which helps fuel economy. Perhaps not in the mountains going up steep grades if you would allow speed to fall to avoid a downshift when not using cruise, but in 9 out of 10 highway situations for 9 out of 10 drivers it helps fuel economy. If you're going to employ "hypermiling" techniques thats a different story, but most drivers don't do that.

 

To share another data point, I'm still on my first tank of gas and purchased last month. The temps have been much colder the past two weeks (30s-50s) and mileage went from 38.7 down to 37.3 and still dropping. From my limited experience, the weather alone is definitely a factor! I didn't even think about that in my decision to get a hybrid, but NC is not too cold.

 

Keep in mind that the factors that cause a hybrid vehicle to have lower fuel economy in the winter also affect the fuel economy of regular vehicles as well.

 

They do, but not to the same degree.

 

I've got a 2014 ESh with 750 miles on the odometer and am getting about 30mpg. I asked the dealership about this, and they told me that it will get gradually better for the first 3,500 miles because the batteries need time to reach peak performance. I expected to be getting 40mpg. Any thoughts on this?

ps - sorry for the cross-post on this other thread, but aside from ElliotB, it seems like this is a different group of people.

 

I don't know, as the first 800 or so miles with mine yielded about 41 mpg. What have your temps. been averaging?

 

I'm in Portland, OR, so it hasn't been too bad - probably around 40 degrees on average. Thanks for the feedback.