Highway MPG

[SimAndy]

Hi. I'm a new member here and have just bought a 2017 FFH Titanium with 25K miles on it.

 

Before I got my car I had a rental from Hertz from Chicago to 20 miles north of Milwaukee and back over a weekend. I drove at around 75mph most of the way and got 42mpg, that is a main reason I bought this model car. I noticed that it spent a lot of time in EV mode especially on downhills and level road just following a down hill.

 

Around town I'm getting about 46mpg (very happy) but recently I went on a long trip, 700 miles each way, which is almost all Interstate. On the same section of road from Chicago to Milwaukee and back I was getting around 34mpg with exactly the same driving style. The last 400 miles I only got around 32mpg at 75 mph and it was all pretty flat driving. Tank fills and computed consumption are pretty close ~0.5mpg.

 

One thing I noticed was that the EV could only hold about 50-55mph on the flat whereas normally it will hold 70+ with no problem.

 

Once I got back to my home city my drive back from work was at 50mpg about 50/50 highway and city driving.

 

Everything seemed to be working on the electric system regarding charging and regenerative braking but it was just unable to use EV drive. I think it was about 5% of the journey in EV. I thought there might be a problem with the motor but as soon as I was home it seemed normal.

 

Has anyone else had any similar experience with highway driving?

Has anyone else had any similar experience with highway driving?

[lolder]

Cold temperatures, rain, headwinds are the most likely culprits.

[SimAndy]

I didn't realize that cold temps had such a big impact. It was 30s up in Wisconsin and then mid-40s to 50s on the trip home. No rain and it didn't seem particularly windy.

[Cobra348]

In the cold temps the ICE runs more frequently to stay at operating temp. The HVB is also out of optimal range for its optimal operation. Essentially the colder it gets the more you'll see this kind of performance. Where I am and with the current temps I'm lucky to see the HVB get 50% before ICE kicks in and screws the MPG all up.

 

Added: I know they dinked around with the drive technology controlling the ICE and HVB usage. I say this because in my '15 HyTi I had no problem hitting mid-40 range in daily usage (by receipts). With the '17 I'm struggling to hit 40 twice in a row! No general change in roads traveled, times, etc. I'm here to say that even in the best temps for the EV usage, ICE is kicking in more frequently.

Edited December 20, 2017 by Cobra348

[SimAndy]

Thank you for the feedback.

 

I have noticed that now it's got cool, and when it was genuinely cold, I find that my HVB is fully charged when I get in even though it was half charged when I parked.

 

I suspected that the car was either an Energi in disguise and driving itself somewhere to fill up or it was a function of the battery being cold, probably the latter. :-)

[lolder]

In mid range temperatures, mpg decreases 2 mpg per 10 deg. F. lower temperature. Mpg decreases 6 mpg for every 10 mph increase in speed. Headwinds lower mpg 3 mpg for 10 mph headwinds. Tailwinds have the opposite effect. Moderate to heavy traffic creates 5-10 mph tailwinds. Heavy rain can lower mpg up to 10 mpg.

 

If you go out and speed in frigid temperatures against winter winds, you'll run out of gas a mile from home.

 

Gas cars get equally bad mileage in these conditions but when you're getting half the mpg in them originally, the effects are half as much in mpg.

[luckyleo]

Florida warm temps seem to be friendly to the FFH. I get low 40s when driving on the highway ~75MPH.

Local driving, I am getting Prius numbers ~50 mpg. When I get to plug in often I see 150 mpge on trip history.

I have only had this car a few weeks but very happy with MPG/MPGe. I really need to start keeping a log to see if the computer is telling me the truth.

[Cobra348]

Florida warm temps seem to be friendly to the FFH. I get low 40s when driving on the highway ~75MPH.

Local driving, I am getting Prius numbers ~50 mpg. When I get to plug in often I see 150 mpge on trip history.

I have only had this car a few weeks but very happy with MPG/MPGe. I really need to start keeping a log to see if the computer is telling me the truth.

Computer is off by 2 MPG or more as compared to gas receipts. The gap will close as you tack up more miles.

[ptjones]

But also odometer is off 1.5-2% to the good side so you make about half of that back. :)

 

Paul