MyFord Mobile Driving Scores Computation

[larryh]

I wonder how the driving scores in MyFord Mobile are computed.  Are they simply the average of the acceleration, braking, and cruising scores for each trip?  Or are some other, and hopefully more relevant, weighting factors used?  Obviously, for a long freeway cruise, the braking score is not going to be very relevant to fuel economy. 

 

The following is from MyFord Mobile for two different days for the same commute.  Note that Thursday's Fuel Economy is better than Friday's Fuel Economy (64 vs 60 MPGe), however Thursday's driving score is worse (80 vs 87).

 

 

 

If I look at the Coach Display in the car, it looks like Acceleration is about 100% and Cruising is about 85%.  If I average that with a 97% brake score, I get 94, which is much higher than the scores shown by MyFord Mobile.  However, I not sure what time interval is used to compute the values in the Coach Display.  They may represent the average over several trips or just the last few miles of my last trip.  Is there a way to reset the scores?

 

Also, I wonder what factors are relevant to computing each of the individual scores.

 

1.  The braking score is obvious.  If it is 50%, you captured only half of the available energy that you could have captured.  You could have gone twice the distance with the recaptured energy had you achieved 100%.

 

2.  Cruising score must be based on speed.  I suspect you get lower scores for higher speeds.  But what other factors affect it?

 

3.  Acceleration must be based on the amount of power you use when accelerating.  But is that really relevant to fuel economy?  If I apply twice the power, won't I get to the same speed in half the time using the same amount of energy?   However, slower acceleration will mean that you will be driving at slower speeds for a longer period of time.  Since the power increases significantly with greater speeds, you will be using less overall energy if you accelerate slowly.  So in city driving, you don't want to accelerate quickly to get up to max speed only to stop at the next block for a stop light.  It would be much better to accelerate slowly and not achieve max speed before the next stop light.  You will use far less overall energy to go the same distance.  However, is acceleration really relevant for freeway driving?

 

I wonder if there is a list of techniques somewhere that one could apply to optimize fuel economy for the different driving situations, i.e. city vs freeway driving and hot vs. cold weather.  If only we knew more details of how everything worked.

Edited July 4, 2013 at 02:44 PM by larryh

[howardbc]

'Sorry, larryh, I really can't answer your questions, but I am intrigued by all the data we can get from this app. I had been wanting to use the Trip1 and Trip2 options, but didn't want to take away display space from things I do still want to be able to see while driving. This data from MyFord Mobile really gives me the same info on how many EV miles I used each day, etc. 

 

I still would like to see the Lifetime Summary somewhere, or is it there and I just haven't found it yet? Also, the odometer is not always showing on the app on my Ipad2 and on my PC. I think it does always show on my Android phone. 

 

But you are correct of course that so much depends on where/how one is driving. I get the impression that the software engineers are still working on the app. That's good news. It's already great but I will keep checking to see what else they might add and/or explain. 

[larryh]

I only access MyFord Mobile from my PC.  I find that Internet Explorer does not work well with MFM.  Firefox works much better.  I haven't had any problems since I switched.

[Russael]

I can't say with any certainty how those scores are computed, but I think it places a pretty heavy weighting on acceleration.  Today, I drove 38.1 miles in EV mode (I was able to snag a 120V charge at a friend's house that I was visiting).  All surface street travel no faster than 50MPH.  But my scores vary quite a bit too.

 

The two longer trips I made (to and from her place, which is 16.2 miles from home), the scores varied a bit, mostly because I had a couple hard brakes on the way there, but it was much smoother sailing rolling home.

 

Going there, I got an average of 167MPGe.  Got 90% brake score, and was rated an 88 for driving score.

 

On the way back, got an average of 171MPGe.  Got 99% brake score, and a 96 for driving score.

 

I think where it really gets you is acceleration.  It does require more energy to move something from a dead stop to speed if you do it quickly vs doing it more slowly and calmly (it isn't linear like you mentioned).  I use enlighten mode and try to keep the energy draw under the second notch.  I sometimes fall behind people in the other lane, but I'm in no hurry either.  I travel the posted speed limit (and sometimes under it now... was doing 45 in to 50 just to conserve a little energy, depending on traffic).  When I look at the coach bars, acceleration is usually where I get a small ding.  I've never had a 100 score yet.  Best I've gotten are 99's and those are to and from work, where I'm used to the traffic patterns and can predict what traffic signals are going to do.

 

I HAVE tried 'cruise control acceleration' and the coach dings that too. :)  Problem is, I don't want to accelerate any more slowly than I already do.  I may fall one car length behind when getting to 40MPH but I don't want to be someone who people get REALLY annoyed with.

 

Though I must admit... the few times I have floored the car from a dead stop is impressive. :)

[larryh]

Looking through my driving scores, they are mostly in the 80s with one 90, all with brake scores in the upper 90s.  However, there are two in the 70s, and both of them had lower brake scores around 85.  It is hard to get good braking scores when the posted speed limit is 55 with stop lights.  The stop lights don't provide adequate warning before turning, forcing you to stop quickly.  They need to come up with more eco friendly stop lights.

[Russael]

Ahhh, your commute is higher speeds too... you could always watch the coach bars and see where it's taking points away.

 

I typically know what stoplights are going to do with my work commute.  I know when they're going to turn by watching the crosswalk signals.  2 of them on my route begin to change within about 5 seconds after the 'hurry up' warning begins flashing and others will flash for 20 seconds or so.  So, if I know I'll make it, I'll roll on, but if I see it start flashing and know I'd have to hard brake before I get there, I'll start slowing down and braking on green lights, and it's always red by the time I stop.  That never mattered much before when I drove my non-eco vehicles, but I watched them then too.  I got zinged for a red light when it was yellow when I entered an intersection, but turned red before I left it.  Paid a donation to the city (they changed the infraction to impeding traffic, no points, non reportable) and have been more careful of that ever since.

[larryh]

Yes, the posted speed limits on all streets and roads on my routes are at least 55 mph (except for the 0.4 miles for the street that I live on).  Unfortunately, there are no pedestrian signals at the stop lights on my route to give an early warning.  Many of the signals change immediately when someone approaches the intersection from the cross street at times and not at other times.  They need to have more predictability.

Edited July 5, 2013 at 01:12 PM by larryh

[larryh]

I experimented with the coach display briefly this afternoon.  It seemed to me that cruising score is based on average speed.  If I go around 30 mph, the score converges near 100.  If I average 55 mph, the score converges to around 75, or something like that.  It doesn't appear to have a long history, i.e. quickly forgets previous speeds.  Since speeds correlate with power, it could also be based on the average power that you have been using.  So if you go down a hill and charge the battery, your cruising score should also increase.

 

Similarly, the acceleration score converges near 100 as long as you keep the power levels low (something like within the first two marks of the power display).  The score quickly falls when power levels increase (i.e. when power exceeds somewhere around the first two marks).  So I wonder if you maintain a steady speed for a long time (and don't go too fast), the score eventually converges to 100.

Edited July 5, 2013 at 07:30 PM by larryh

[howardbc]

I too have been wondering how the "Driving Score" is computed. I couldn't find anything about it in the owner's manual. My braking scores are almost always pretty good (80s-90s) but my driving scores (60s-70s) are not as good. I guess it's because I may occasionally go a little over the speed limit. I don't swerve and change lanes a lot or things like that, but obviously there's something I'm not doing the best. 

I can see the blue circle that tells me my braking stop after each stop, but is the driving score also illustrated somewhere on the dash or display? I keep the "Status" display showing the outline of the car on the main display 99% of the time. 

[Russael]

Yes, there are coach bars in the instrument cluster somewhere... I'd have to dig for it myself.  But there is nothing for 'driving score' built in to the car.  Closest thing to it is the coach.  The driving score is based on the coaching data.

 

If your driving scores are in the 60's to 70's... do you do a lot of highway travel (speeds greater than 50MPH)?  In that case, it may be dinging you for higher cruising speeds like Larryh mentioned.  I am not a spirited driver by any stretch of the imagination and I have not yet had the Fusion on the expressway, but the speed limit here in Michigan on most interstates is 70 with a minimum of 55.  I will putz along in the right lane at 65, and that does save fuel (especially with my Expedition since it's so huge).  You'll find yourself not hitting the brakes anywhere near as often at that speed which is nice too.  I don't like going slower than that.  People already fly by me as if I'm standing still... but when I go through construction zones that are around 55, I'll slow down to that and the economy meter in the truck will start climbing pretty quick, but there's no way I can do 55 without causing problems.

 

Even though the car has regenerative brakes, it is still more efficient to maintain a constant speed.  If you find yourself coming up on people and needing to slow down and re-accelerate, you will use more energy to cover the same distance, especially on the expressway.

[Depauwler]

She talks about the Coach at 40sec in.

 

http://www.youtube.com/watch?v=d05Vz8AWNaw

[dlb92]

I always got scores 90 and below and the only score that was low was acceleration so I made sure the energy stayed under the two bars while accelerating now I consistently get 92-94 driving scores and at least 27 miles off the battery.

 

It will piss off the people behind you though if they can't get around you!

[Depauwler]

Yeah.  I usually get 90+.  I usually accelerate slowly anyway, even before the Energi, so my driving habits haven't changed that much, except I'll often go the speed limit and I don't use the climate control as much.  It makes a difference when you can see your estimated miles drop by a third to a half when you turn on the AC. ;)

 

Still not sure how it's computed though.  Is it an even average of the three?  Is it the lowest?  Someone want to tank one of the three to see what they get? ;)