Which one is right?

[Errol Ikalina]

Hey guys,

Loving my cpo 2013 fusion hybrid, still lots to learn and one thing that bugs me right now is the mpg. I have myview set to show empower and while driving it is showing me around 41mpg, it fluctuates depending on how I drive but when I switch the car off it shows another screen. I think it's the summary and it shows another mpg reading but this time much lower at around 34.5mpg, which one is the right one?

[murphy]

They are both right. They cover different time periods. I recommend that you reset them so they represent your driving and not the previous owner's driving.

[Griswald]

Adding an Ultra Gauge will clear things up.

 

However, the number in the center of the left screen is "lifetime" MPG. In quotes because it can be easily reset, so it really isn't lifetime unless you have never reset it (I haven't and mine is now 43.4 for 14 months). I guess the best name would be "Long Term MPG".

 

The screen that is only on for a few seconds after you turn the key off is a trip meter, it tells you how well you drove since the last key ON cycle. To me, this is the most important one to learning how to drive these vehicles at their best.

 

The Ultra Gauge I mentioned earlier is a plug-in device that does a much better job tracking of these and other data. Engineers (read "geeks") love data!

[mwr]

The screen that is only on for a few seconds after you turn the key off is a trip meter, it tells you how well you drove since the last key ON cycle. To me, this is the most important one to learning how to drive these vehicles at their best.

I don't find that to be true for me, probalby because many of my trips are quite short. Differences in starting and ending battery charge for short trips can produce crazy mpg numbers that really don't mean anything. For example, more than 100 mpg displayed for the 2.4 miles from a market to home, starting with a very high charge.

Edited April 28, 2015 by mwr

[Griswald]

Getting over 100 mpg is quite a task, consider yourself proud. Doesn't matter the length because the total number of miles driven by the gas used is what makes up that number.

 

If you make that same trip 50 times, you've gone 100 miles and still only used 1 gallon of gasoline.

 

Here is the way I look at it...my 8.6 mile commute normally gives me right at 40 mpg. If I find I am only getting 32, I try to see what I did differently so I don't do it again. Or if I get 48, I try to figure out what I did right. Its all just a learning curve!

[mwr]

Getting over 100 mpg is quite a task, consider yourself proud. Doesn't matter the length because the total number of miles driven by the gas used is what makes up that number.

 

If you make that same trip 50 times, you've gone 100 miles and still only used 1 gallon of gasoline.

 

Here is the way I look at it...my 8.6 mile commute normally gives me right at 40 mpg. If I find I am only getting 32, I try to see what I did differently so I don't do it again. Or if I get 48, I try to figure out what I did right. Its all just a learning curve!

No, really, that 100+ mpg doesn't mean anything. All it means is that the car was running in EV mode almost all the time and the battery charge went from full to almost empty. So the big mpg on that short trip gets balanced by lower mpg later caused by the depleted battery from that 100 mpg short trip.

[Errol Ikalina]

How do you reset the lifetime trip information after switching off the car?

[Texasota]

No, really, that 100+ mpg doesn't mean anything. All it means is that the car was running in EV mode almost all the time and the battery charge went from full to almost empty. So the big mpg on that short trip gets balanced by lower mpg later caused by the depleted battery from that 100 mpg short trip.

I think mwr is making sense here. The only thing I would add is that you drove on mostly EV during that on/off cycle because the HVB SOC was high and the SOC was high because you consumed gasoline in the previous on/off cycle to achieve that high SOC. It was your previous on/off cycle that subsidized the 100+ MPG on/off cycle. And as mwr pointed out you are going to be penalized on the next on/off cycle.

[billford]

Adding an Ultra Gauge will clear things up.

 

The Ultra Gauge I mentioned earlier is a plug-in device that does a much better job tracking of these and other data. Engineers (read "geeks") love data!

A little off subject, but can you post what you can read with the Ultragauge on the hybrid please.

[Griswald]

A little off subject, but can you post what you can read with the Ultragauge on the hybrid please.

You cannot read any hybrid specific info with it, only the normal Ford parameters...speed, temps, trip info etc.

 

And I strongly disagree with MWR and Texasota, going 100 miles and only using 1 gallon of gasoline is a HUGE deal, no matter how you did it. The fact is that if you can learn where and when to use other-than-gasoline to charge the mains back up, you are that much farther ahead. Here's a real-world example. On my way home from the town and shopping district down the road, a route I need to drive quite a bit, I learned (by studying the ultra gauge read-out) that if I let the car roll down the first hill, I can make it over the second hill without ever going into ICE mode, all I need to do is drag the brakes until the car starts recharging itself, I found the right combination of speed and brakes that charge the mains without ANY gasoline use. There is also a long kind of downhill stretch right before I need to turn into my housing plan. If I hit the end of the last curve at 60ish, I can coast and brake enough in that last stretch to give me almost a half a charge before I pull into my plan. That gets me enough battery to drive all the way to my house and back out again without using the ICE. There are 2 other similar places on that commute. When I first bought the car, I could easily hit 50 MPG on that stretch. Now that I use those techniques, I can easily hit 60 and have gone as high as 72. Those are REAL gains. My lifetime average (truly lifetime as I have never reset it) has gone up .4 mpg since I got the ultra gauge, and I expect it to keep going up.

 

The thing about data is its useless until you use it.

Edited April 29, 2015 by Griswald

[hybridbear]

How do you reset the lifetime trip information after switching off the car?

When you turn off the car you will see two MPG displays, one that is your Trip Summary and the other which is the Lifetime Summary. You also have an MPG display which is visible on the Empower, Engage, Inform, Enlighten & MPG Graph screens which can be reset at any time using the left "OK" button. Finally, there are two trip meters which show MPG. Be sure to turn on the "Advanced" view to get more data.

 

The Owners Manual explains how to reset these screens. Check out the videos on the Ford Owner website for more info about the dash screens as well.

[Texasota]

The fact is that if you can learn where and when to use other-than-gasoline to charge the mains back up, you are that much farther ahead.

Your statement would be true if there was a way to charge a hybrid's HVB with something other than gasoline. In a hybrid that is not possible. In a PHEV or a BEV where you are charging the HVB with grid electricty your statement is true.

 

In a hybrid, such as the FFH, anytime you capture energy to recharge the HVB (by regenerative braking or when going down hill) you are not charging the battery with something other than gasoline. You are simply recovering some of the energy previously expended by burning gasoline. To get top the top of that hill you burned gasoline and when you go back down the hill you recapture some of that energy from the previously burned gasoline. This is a very good thing and is what makes a hybrid more efficent than a conventiona ICE car. Likewise, with regenerative braking you are simply recapturing some of the energy from the previously burned gasoline to achieve the velocity that you are now reducing with your regenerative braking.

 

All of the energy (100% of it) that goes into charging your HVB comes from gasoline with a hybrid.

Edited April 29, 2015 by Texasota

[Griswald]

But you CAN get better at using the physics of moving mass to help your charging sydtem.

Edited April 30, 2015 by Griswald

[Texasota]

But you CAN get better at using the physics of moving mass to help your charging sydtem.

That is true and explains why one driver may achieve 50 MPG with a FFH and another driver may only achieve 40 MPG given the same car and driving conditions. But the same also applies (to a lesser degree) for a conventional ICE car. The way your drive them makes a huge difference.

 

But back to what mwr was originally saying is true. That 100 MPG is very misleading because it was heavily subsidized by energy derived from burning gasoline in the past when you climbed the hill and/or acheived a high SOC on the HVB. If you were to set your trip display to measure your mileage over 10-20 cycles of your commute you will likely have an average MPG only in the 40-50 range. But, 40-50 is nothing to sneeze at! The FFH is very impressive.

Edited April 30, 2015 by Texasota

[Automate]

if I let the car roll down the first hill, I can make it over the second hill without ever going into ICE mode, all I need to do is drag the brakes until the car starts recharging itself, I found the right combination of speed and brakes that charge the mains without ANY gasoline use.

 

This is an interesting question. How much if any brakes to use on a downhill before an uphill. It's tempting to say keep the momentum in the car and don't use the brakes because even through regenerative braking is nice, you still loose about 30% of the energy charging the battery when braking and then taking it back out of the battery later. On the other hand if you don't use the brakes your speed will be higher at the bottom of the hill and therefore air dynamic losses are greater because they go up with the square of the speed. So your speed at the bottom of the hill will determine if you are better off using your regenerative brakes or coasting.