Regenerative braking question / mpg

[Severdog]

To be fair, I really haven't seen much difference to my mileage after "break-in." Perhaps I haven't broken it in yet at 30k. First trip that I took was on the highway and got roughly 25mpg there and back over 200 mile trip. I do notice some degraded numbers in the winter when the battery is low in the morning after a cold night, and the winter blend doesn't carry as much energy. Probably a 10% hit in mileage, and my weather is mild compared to most. Give it some time and you'll be pulling some great numbers. (oh, and idling will definitely kill mpg numbers)

Sponsored

 

[dochawk]

Probably a 10% hit in mileage,

If the only difference in fuel is a change from all gasoline to 10% ethanol, the hit from that should be about 3%--ethanol has about 2/3 the energy content by volume.

But other (non-fuel) things could be happening at the same time that account for another 7%.

 

[Severdog]

If the only difference in fuel is a change from all gasoline to 10% ethanol,

I'm quoting Google AI on this topic; I don't claim to be a petrochemical expert. I do see lower fuel economy in colder temps and "winter blend" appears to be one of the variables negatively impacting the performance. Other than quoting this, I don't know what I'm talking about.

• Fuel economy
  Summer blend gasoline has 1.7% more energy than winter blend gasoline, so your gas mileage may be slightly higher in the summer. However, winter blend gasoline is cheaper because it contains more butane, which helps gas ignite in lower temperatures. This added butane makes the gas slightly less energy-efficient.
  

 

[dochawk]

My comments only apply to the substitution of 10% ethanol for gasoline! Mix in butane, and my hands go up in a shrug, as well as for any other change in formulation.

Here, we're stuck with California gas year round, except for a small amount trucked in from Arizona.

I first noticed that 3% or so empirically, when I was driving the 450 miles from San Jose to San Diego fairly often in the late 80s, and noticed my mileage, in the high 20s, was lower by about 1 when I went out of my way to pick up the cheaper gas at Beacon. I thought it was was getting a deal, with more octane for a lower price, but it turned out that beacon was 10% ethanol, and the others were not, so the mileage difference was a bit more than I was saving anyway! It was a some years before I found the math, which worked out to about the same.

Intake air temperature should help, too, making the engine more efficient.

 

[Ziggy73]

Still on my first tank of gas with a spanking new powerboost, and have a few observations that I hope some folks can help explain.

The displayed mpg is so far poor/bad compared to sticker. 19.4 mpg with about 40% highway and 60% very short trips around town for a total of about 347 miles so far. The display says about 254 miles on gas power and 93 miles on electric. I have also run the truck in idle quite a bit while reading the manual and tinkering with all the set up stuff. Maybe even 60 minutes in total.

Maybe worrisome, I can hear the regen brakes when I start coasting from a low speed (15-20 mph), and when I coast into speed bumps going up a local hill when at 15 -25 mph.

The manual says the regen brakes are supposed to slow the vehicle when coasting. Such programming surprises me, but I am just learning this drivetrain and maybe that's a smart thing. I suspect though (and very much hope) this only occurs when coasting is started at low speeds. However the manual isn't clear on that point and I wonder if one can hear the regen brakes if coasting is started at 35 - 60 mph.

But what I do know is that the displayed mpg is about 15% less than sticker, and I wonder if the regen braking is causing this.

Did persons get crappy mpg for the first few tanks with the powerboost ? Are short 10-15 minute city trips very bad for powerboost mpg despite that being the supposed advantage with hybrids ? Could the regen braking while in coast also cause low mpg ?

I got pretty good MPG from the get-go, but you won't get great until around 9,000 mi. The regen breaking should help your MPG because you're putting energy back into the battery which will help you after the light or stop sign. Being brand new to the truck you're going to also get better several months into ownership as you learn, I use my EV coach or I can see how much acceleration battery I have before it kicks into gas, if I know I'm about to stop again I can let off right before it kicks over to the gas. There's a YouTube video on how to draw a PB F-150. However, out of all of the tips the one I use the most and the easiest to use is accelerating with moderation up to speed, usually three to five MPH over the speed limit, then tap the brakes and then gently coast for the next 5 to 1.5 mi. These are usually only good for around 45 to 60 mph, much higher and you're not going to get much benefit, however the electric motor is always benefiting the truck whether the engine is running or not, like I said there are things you'll learn over the next few months, I would suggest joining a Facebook group if you haven't already, for the most part we'll teach you quite a bit.

 

[dirtwinston4prez]

Many thanks Ziggy. And much thanks for youtube / facebook heads up. I did start using the fuel economy display and keeping tabs on the things that affect fuel consumption.

Now on second tank, getting 22 combined avg mpg with about 40% freeway driving, about 30% battery miles. The powerboost efficiency seems to shine best during 5 - 35 mph rush hour. Plus, maximizing battery miles gives me something to do during the grind.

Problem is, previous F150 was 2.7L and loved how its torque started to kick in just below 2000 rpm.

After crossing over 1000 miles, its going to be really tough ignoring 570 ft x lbs with the 3.5L. Early weekend mornings, that drive train will feel awesome on freeway uphills and on-ramps with good merge visibility.

Sponsored