Maybe driving style doesn't matter?

[Kelleytoons]

This is an odd one.

 

I've noted this here before, but my wife has sort of a heavy foot.  She loves to hit the gas and brakes in equal amounts and no amount of coaching has ever made an impact on her.  In general I don't ride with her as a passenger because... well, it drives me crazy (or at least crazier).

 

Last night she took me out for my birthday and we went on a route I'm quite familiar with, as I drive it three or four times a week.  It's about 20 miles one day, with equal amounts of city/highway (highway at 60mph, city at 35mph).  In either case she would drive the max plus five, but when I drive I generally stick to the limits.  I also practice the very best braking/gas use (always at or near 100% braking and very slow starts and movements).

 

Under the current weather conditions (highs in the 80's) I'm getting mpg in the upper 50's to low 60's.  Sometimes I get in the mid 60's, but I always think of it as a "perfect run" when that happens.  Last night, driving to the restaurant, I got 58mpg, which wasn't great (I had some traffic issues and missed some lights).  At the eatery I, well, let's say it was a celebration and I partook of some beverage which caused me to need a driver of better equilibrium.  My wife, who had stuck to ice tea, drove home.

 

As she drove it was the usual hellish jackrabbit starts and pounding brakes finish, and we even got stuck for about 20 minutes for an accident (so just waiting there with the engine on -- it was battery power, thank goodness, but it used it all up).  When we got home I couldn't wait to see how bad it was (and yet I knew I wouldn't say anything to her about it -- momma didn't raise no fool).  She proudly announced "55mpg!" and I looked over there and that was indeed what it said (55.6 to be exact).

 

WTF?!?  How did that happen?  20 miles of between 40 and 65 mph, with a 20 minute stand still delay and brake scores (I watched) of no better than 65% and the fastest acceleration the Max can do and still that?  I, with my very careful driving, could manage no better than 3mpg better?

 

Now, to be fair, the trip TO is always worse than the trip home.  Maybe it's slightly uphill (hard to tell in Florida).  And part of that, I'm sure, is EV+ mode (when I get into the mid 60s it's nearly always on the trip back -- so perhaps I would have been at, say, 66 mpg).  Still, 55mpg over 20 miles at those speeds with about the worst driving imaginable is pretty impressive, right?

 

I'm beginning to think now that trying to teach my wife how to drive better is a lost cause.

[SPL Tech]

I think it is a bit silly that you consider 57 MPG on a car rated for 42 as "not that great." Also, comparing data from a single trip is meaningless. Have her drive as she does for a month and then compare that data.

Edited January 5, 2015 by SPL Tech

[fotomoto]

I describe my wife as a digital driver:  gas and brake pedals are either on or off.  She views speed limits as the minimum speed one should drive!   :shift: We drive identical cars over many of the same routes and I can use the MyFordMobile service available to Energi owners to compare our data.  She has consistently lower fuel economy.  On routes that I can make on 100% EV, she burns gas, etc.  

 

I suspect you just caught your wife "having a good day".  LOL

Edited January 5, 2015 by fotomoto

[Kelleytoons]

Yeah, you're probably right (and to the first poster -- although I've only driven about 5K miles since our lifetime average is approaching 50mpg and since most of those miles were in the summer when I was lucky to get in the high 40's, I think it's reasonable to assume that getting in the mid 50's now is pretty average.  Since I've turned off the A/C and been making the same trip to the PT three times a week over the last two months I consistently get the mileage I posted.  For example, today both ways I got between 62 and 64 mpg, and while those are the reported miles -- I know there is a difference in the gauge but that's all I can go by in any one trip -- I consider those "great" for the speeds I was traveling).

[drdiesel1]

I'm to the point I don't even worry about MPG's anymore. My readout is always around 80 mpg,

so it's a moot point for me anymore. I still drive to get good MPG numbers, but it's become the

norm to see 80 MPG on my display :happy feet:  Oh! I don't let anyone drive my C-Max.

The late braker has her own wheels. It's taken my 15 years to get her to stop warping rotors out every 2 years :yahoo:

[Adrian_L]

You can't compare two trips unless the conditions are exactly the same--engine was at the exact same temperature when starting.  Battery level was the same.  Sometimes I make a 35 mpg trip one way and a 47 mpg trip coming back.  Same route--same technique.

 

But I agree with SPL---saying 58 mpg is "not great" is wierd.  Unless you're getting 75 mpg on a daily basis.

[Smiling Jack]

Yeah, these C-max's are really great cars.

 

Even if we drive them mindlessly, they still give great mpg in spite of the driving style.

 

The cars care even if we don't.

[Kelleytoons]

You can't compare two trips unless the conditions are exactly the same--engine was at the exact same temperature when starting.  Battery level was the same.  Sometimes I make a 35 mpg trip one way and a 47 mpg trip coming back.  Same route--same technique.

 

But I agree with SPL---saying 58 mpg is "not great" is wierd.  Unless you're getting 75 mpg on a daily basis.

 

You kind of misread my post -- happens, I know.  I drive these routes (back and forth) ALL the time, under nearly identical conditions (I admit weather does vary, but I've driven enough in the various types to know how it affects it).

 

To put it another way, I can tell you within 1 mpg what I will get when I turn off the engine... I'm almost never wrong.  I've now got the sense of how the traffic was and what I did in my driving to know what I end up with.  Which is why it was so surprising to me riding as a passenger, because my guess would have been off by at least 8-10 mpg of what my wife ended up with.  Since I never brake and accelerate how she does I made some assumptions and. while the topic of this post is somewhat tongue in cheek there is a real point here which is maybe it really doesn't matter as much as we think.

 

But is it wierd (sic) to think that 58mpg is not great when I consider great to be in the 60's?  I don't think so, but I guess we just differ on how we judge our cars and our own capabilities (I mean, I'm a very good tennis player and I might play someone and only beat them slightly because I played poorly, whereas you might consider yourself having a great game to do that.  Different strokes).

[Adrian_L]

Oh please.  You know as well as every one on the forum that "not great" means "mediocre" or "lackluster".---when it pertains to a 58 miles-per-gallon journey then.............yes............weird.

 

It would be the same if my son came home with 9 out of 10 on a test and I said "not great" because he usually gets a 10.

[Kelleytoons]

Sorry -- not great to me means just that.

 

(I assume you have a special dictionary I am not aware of -- link would be appreciated).

[Adrian_L]

I ran this question past my friend---an English professor and here's what he said:

 

"not great" typically is used to refer to a "less than desirable" situation.  For example--"Bill, how did you do in your test?"   "Not great"  Meaning that Bill probably passed but didn't get a good score. 

 

Claiming "not great" means "a slighty lower level than great" or "almost great" is not how the term is commonly used.

 

Let's stop splitting semantic hairs and agree that a 58 mpg trip is pretty damned fantastic for a car that is rated at 42 mpg.

[Smiling Jack]

I am fairly sure that if I were to run the question past my old Logic Professor he would say that "not great" means everything other than "great."

 

To be sure, the phrase "not great" may be very commonly used to mean what the English professor says.  That does not mean that it can no longer be used literally.

 

I think we should extend to Kellytoons the courtesy of allowing him to use the phrase literally if he chooses to, particularly since he has taken the trouble to explain at length not only what he meant but why he chose to express himself in the particular way that he did.

[Kelleytoons]

LOL -- maybe because I was both an English Major and a Math minor do I find both explanations interesting as well as amusing.

 

Yes, I meant it literally -- not great, and certainly not "undesirable".  But I also think (for the purpose of discussion) that the expression "great" (along with all the others like "super" and "fantastic" and "wonderful") is highly overused.  I reserve it for the times that something is extraordinary.  

 

With Maximis that means in the 60s, something I cannot achieve all the time.  I *can* however, get in the 50's with no particular effort nowadays (without using A/C) and today was a good example.  I filled the tank and saw that my reset said I got 58mpg average on the tank (it wasn't on empty so it wasn't a 600 mile tank).  That's with no particular care or effort on my part, and at speeds that probably averaged 50mph (there isn't any limit around here I drive less than 40, and a lot of stretches I drive 60+ on).  Is that "great"?  I think it's very good and I'm happy with it.  But it ain't great.  (Someone like Paul does "great" in every sense of the word, as well as the folks in the 700 club).

[plus 3 golfer]

The problem with using logic philosophically to define great is that it doesn't quantify the degree of greatness. There is no "measure" of the extent of the greatness.  So one then looks at the context in which "great" was used.   For me it's simple: when one quotes numbers and comparisons (upper 50s, lower 60s, 58, 55.6) like in the context of the post,  "wasn't great" for me means "not as good as I usually do".   All quoted FE numbers may be viewed as  "great" compared to the EPA FE but that's not within the context of the post. 

 

I can relate to what Kelleytoons post is about yet it seems others have yet to grasp it and I agree with it.  I will virtually always get better FE driving the same route than my wife does.  She drives the car for 2 or 3 trips in a row and gets around 41 mpg (she drives with a heavier foot, higher speeds, and not as good a brake score as me).  Then, I drive the car on virtually the same route and I get 42 maybe 43 mpg.  Is 1-2 mpg difference worth consciously trying to adjust ones driving style.  

 

IMO, speed is the most critical factor in achieving high FE numbers. As I've said many time, I can get high 50's low 60's for the same trip if I stay off the freeways, coast to stops and so forth or mid to upper 40s if I drive at around 63-65 mph on the freeways.  But that's not going to happen as saving time is more important to me than any fuel savings.  Increasing FE by 1 mpg results in about $20 savings a year currently with diminishing returns as FE goes up (based on 17000 miles per year, $2 per gallon and 41 mpg). Even if we could get 51 mpg average, the savings would be about $160 a year but that will never happen. ;)

[Kelleytoons]

I also just came back from an interesting experience.

 

Taking into account that the trip one way is never quite the same as the return trip, we made a trip (four folks and full luggage loaded) of around 228 miles each way on a short vacation.  On the way down I adjusted for best fuel economy in the GPS and thus went on many smaller highways and a shorter distance traveled overall.  The couple's husband griped about us not taking the "best route" which was one single shot on a main interstate.

 

But here's the funny thing -- on the way there I averaged 53mpg, which I thought was pretty good (again, not "great") and it took almost exactly 4 hours (minus the stops, but I was counting from computing time on the GPS).  The way back, due to his gripes, I took the interstate at high speeds (70+) and averaged just slightly over 40mpg (very bad, for me).  The kicker?  It was almost exactly the same time (it was one minute faster, again according to the GPS).

 

The interstate route was longer, naturally, which at faster speeds ended up being nearly the same time traveled.  Going the short way seemed longer, because we traveled much slower and we made a lot more turns and road changes, but it wasn't.

 

Now, my friend was still griping when I pointed this out to him, because he said if HE had been driving he would have gone much faster (faster than even 8mph over the posted speeds, in the 80's).  I still don't think it would have amounted to much more than 15 minutes time savings.  But for sure it would have been much lower mpg.

 

This isn't speaking to your point -- driving speeds on the same route obviously affect your travel time a lot more than taking different routes with different speed limits as our trip did illustrate.  But I did think it was an interesting thing to think about in terms of where we need to go sometimes.  Sometimes driving a lot faster doesn't save much, if any, time, and it sure wastes a lot of gas (particularly in our vehicles).

[fotomoto]

Yes, I see this on a local basis.

 

We have two ways to get across town to major shopping points.  My wife's preferred route is commonly called "the back way" along the outskirts of town while my route is through town.  Hers' is longer and higher speeds while mine is shorter and lower speeds.  My route delivers much better mpg's.  They both start and end at the same intersection/traffic lights so I've come to watch cars taking the back route and about 6 times out of 10 we arrive at the other intersection at the same time.  The other 4 times is a toss up as to who gets there first.

[plus 3 golfer]

A while back I posted a graph of a 42 mile trip taking a route with lower speeds, stops and so forth showing various data I recorded on the trip. On the way back, I took the faster route back which is actually shorter by 5 miles.  Here's the summary of both: 

 

42.2 miles, 19.9 EV miles, 55 min. 59 sec., 50.3 MPG; 45.2 MPH, 0.83 gallons of fuel 

37.1 miles, 13.8 EV miles, 44 min. 42 sec., 44.7 MPG; 49.8 MPH, 0.83 gallons of fuel

 

If my goal is to maximize FE, I'd drive the longer trip every time and get around 50.3 mpg at about 45.2 mph but if my goal is to save time, I'd take the higher speed trip but only get 44.7 mpg but I'd average 49.8 mph and save about 11 minutes (about 20% in time) due to the shorter distance and higher speed.  Coincidentally, I used exactly the same amount of fuel on the outbound and return trip of 0.83 gallons.  So, in this case the higher speed trip saved time and the fuel use (and cost) was the same as the slower speed trip.  

 

Our normal trips (3-5 times a week) are about 25 - 70 miles RT where taking the freeway vs side streets would result in virtually identical distances but time savings is significant when using the freeway.  Of course the trips at higher speeds result in "poor" :) FE  

 

My point though is that one's FE highly depends on speed and if one wants to impress one can certainly alter their speed (just driving slower or finding alternate slower speed routes) and post "great"  :) numbers .   My driving style hasn't changed with our C-Max.  I've always had FE in the back of my mind going back to my first diesel in 1976.  But I don't sacrifice time for FE. Hence, our overall FE is right at 41.0 mpg (tank calculated) but would likely be close to 47 mpg if we stayed off the freeways around Phoenix.

[markd]

As much as I love my new car the mpg's are in the tank, it's been very cold, between 10 above and 10 below zero and I can't get much better than 20mpg at these Temp's.

[Kelleytoons]

Yipes.

 

At those temperatures I think *I'd* stay inside along with your mpg (my philosophy is to never go outside when the temps are below the mid 40's.  Luckily, being retired and living in Florida, that's pretty easy to stick to).

[ScubaDadMiami]

I just travel at moderate highway speeds, and I get a nice balance of MPG and fuel economy. Last summer, at 68 MPH, I averaged 45.6 MPG with a fully loaded vehicle, air conditioning running almost the entire trip, over the course of 5,400+ miles while driving from Miami to just across the border from Maine and back to Miami, even with several out and back trips to the steepest New England mountains.

[markd]

If you drive 68 mph on the hiway in Indianapolis you'll get ran over. I attribute the poor mpg's to heat and idling.

[SnowStorm]

So back to "driving style" which, per original post, means fast starts, higher speeds and quick stops.  We know all the things that can make To/From mileage different - prevailing winds, altitude, engine warm-up, battery SOC and EV+.  Kelly expects he would get 66 on the return trip versus the wife's 56.  His speeds are about 5 mph slower so that accounts for about 5 mpg - at his wife's speeds he would get 61.  That leaves about 5 mpg (8%) to jackrabbit starts/stops based on our limited data.  (You can make your own decision as to whether that difference is "not much" or not!)

 

Regen braking is great but it's also over-hyped.  A couple of stops in 20 miles with a 50% score versus 100% just isn't going to make much difference.  Remember, kinetic energy is proportional to speed squared, so you can coast from 60 to 30 (using up 3/4ths of the energy), hit the brakes "hard" (50% score) and you still only "lost" 12.5% of the original energy.  It all depends on how many stops per mile and at what speed you hit the brakes.

 

With acceleration there may be even less to worry about.  Gasoline engines are not efficient at light loads - that's the main reason we have hybrids in the first place.  Very slow acceleration might not help at all (except that your average speed is less!).  The car has a ton of programming based on data none of us have.  Step on it and go!

 

All of which points to the fact that lead-foot driving simply does not negate the advantage of having a hybrid even if it hurts mpg a bit.  Your mileage might be "not great", but who cares at 55 mpg!  I love how Smiling Jack put it:

 

      "The cars care even if we don't."

[Kelleytoons]

That's a nice analysis (although, as you point out, it's based on limited data.  Not sure I could or would want to conduct experiments involving my wife :>).

 

At the very least it makes me feel less worried about the times I need to sharply accelerate in order to perform "correct" maneuvers to get out of the way of folks or otherwise be safe, as well as the frustrating times I accelerate only to see the signal in front of me abruptly turn red even though that particular signal has never done it that way before (they seem to be shortening the yellow light time more and more here in Florida) so that my brake score is less than perfect (it's almost never less than 70% even then, as I'm pretty good at still not jamming on the brakes).

[fotomoto]

 

Regen braking is great but it's also over-hyped.  

 

I realize this is the hybrid forum so I'll skip the details but we Energi owners have found a method to bank excess regen energy back into the battery and save it.  In the same scenario in hybrid mode, the cars' programming would seek to immediately burn off that excess to keep the battery SOC within set parameters.   On a short 45 mile hwy trip that I regularly take, I can bank almost 5 EV miles using this method.

 

At highway speeds, I've found (via scangauge) that it's best to use the brakes moderately hard for max regen (max brake scores) and not coast.  Too much kinetic energy is lost to wind resistance and tire friction while coasting that could be going into the battery.

[shinytop]

Coasting further not only allows for more charge of the battery but often means longer periods with no gas being used, the best driving for low mileage you can have.  I have not used scangauge but the harder the stop the more difficult it becomes to stay out of friction braking which shortens the life of your brakes.  

Edited January 17, 2015 by shinytop