Terrible Highway mileage!

[AZBill]

That's not my understanding, at least in the way I think you're implying. The Mach-E motors are permanently engaged, so there is no actual coasting. Without being able to disengage them from the axle, there is no efficiency gain in the way I think your suggesting.

Not a pure coasting, but just enough power can be applied to overcome the back EMF of the motor, and thus provide no torque at the wheels. On some other threads some people have measured the power during cruising and found it was effectively not using the front motor except during acceleration. It was a really old thread.

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[dbsb3233]

On a road trip I figure it out all ahead of time based on what I think my consumption is going to be based on speed, elevation changes, etc. I familiarize myself with the DCFC stations along the route and plan where I am going to stop. I also plan for alternate stops in case the stations are out of service.

That's exactly the way I do it too. I'm a big pre-planner. Makes me more comfortable knowing all the viable options, not just for planning the best route and stops, but for what's available as a backup if a station isn't working.

I still completely ignore the GOM regardless of whether I am planning or winging it. Since I have never had a GOM before, I don’t worry about the one I have. I actually wish I could remove it from the display and add something useful in its place.

I get what you're saying, but I still find the GOM useful for a simple mental approximation of how well the car is doing relative to the plan on a given leg. I could pull out the calculator and manually calculate it from the Battery%, but having it right there in miles makes it easier. At least when it reasonably approximated highway speed driving, like it used to. Now it's much further off for me, making it almost worthless.

Another big difference vs ICE is how much more the conditions affect the mileage. Driving ICE I might see a 10-15% variance in mileage from speed, cold temps, wind, wet roads, etc. But in an EV it can easily vary by 20-40%. I'll get 3.5 MPK on one road trip leg and 2.2 on another. I might plan a leg for 2.8 MPK but find it was 30% worse due to wind and cold. And with so few DCFC stations, it can be important to monitor the difference between planned and actual along the way.

We've done well over 20k miles in road trips in this car now, and while it's rare, there have been a few legs where the progress along the way was much worse than expected. Once we pulled in at just 2%, for a regular leg that we usually arrive around with ~20%. Unexpected headwinds made a huge difference that time.

 

[meinhard57]

The Mach-E has terrible highway mileage! I was in Quartzite,AZ heading to Glendale,AZ which is about 120 miles. I charged up with 220 miles of range but when I got home I ended up with 30 instead of 100 left and from Palm Springs,CA to Quartzite,CA was the same way, Ialmost ran out of charge! I should of got to Quartzite with 15 miles of range left but had to U-turn and goto a Hampton to charge up enough to get ust to Quartzite. What is the driving logic on the highway?

I find that headwinds and elevation drop/increase GREATLY affect the efficiency. I generally drive whatever the speed limit is, up to 5 over. Never over 70 on highway. On the highway, I get anywhere from 2.0 to 4.0 Mi/kWH. Over the time I have had the car, I have averaged 3.55 Mi/kWH. Mostly highway driving, probably 70/30. Which is right at or slightly above EPA estimate of 247 miles at 100%.

 

[Thunderanger]

That's fine around the city where there's more chargers, and of course with a home charger. That's exactly what I do when deciding which nights to charge at home. I usually just plug in any day I get home below 50%.

But it's a whole different story when on a road trip where the only DCFC might be 50... 80... 120 miles apart. The gas model only works when there's stations to refuel all over the place. But road trip DCFC is usually quite sparse. The fueling situation is really more like flying an airplane between airports than driving an ICE car.

I do look forward to the day when DCFC is every 10-20 miles instead of every 50-120 miles though. Then we'll be able to "wing it" more.

Bingo~~~!!!!!

 

[Thunderanger]

Mine used to be like that too (pessimistic). Which I found to be a good thing since the only time I care about range is on road trips (70-80 MPH speeds) where mileage is lower anyway. I would often track the difference between the nav miles-to-go and the GOM. That gap (buffer) would still usually shrink slightly, but it was pretty close. I might leave a DCFC with a 50 mile gap, and arrive at 35, being "off" by only ~15 miles. Pretty good.

But one of the updates over the last 3-4 months screwed that all up. The GOM went from pessimistic to optimistic. And it wasn't just in the first few weeks with little new driving history. For instance, on one of the last legs of a 1700 mile road trip last month we left a charger at 100% showing ~100 mile buffer and arrived with only a 30 mile buffer. Off by a whopping 70 miles.

If that keeps up, it's gonna be really hard to use that buffer as a semi-reliable tracker anymore.

In essence, the old GOM seemed to assume high-speed highway driving, while the new one seems to assume low-speed city driving. Which sucks.

Exactly.

 

[Johnny572]

You do know...that when you decide to post anything regarding mi/kwh or GOM mileage estimate discrepencies that this is going to be the response. You have been a member of the forum for almost a year. No one is intentionally trying to troll you; but having said that, you can literally see a post about this topic almost daily/weekly and A LOT during the winter.

People are just explaining that having an EV like this, you have to always take speed, temperature/weather, HVAC settings, terrain etc into account to explain the observations youre seeing.

Thank you….you nailed it!

 

[Johnny572]

You got the wrong battery. Take it back to the dealer or sell it.

Bingo!!!!

 

[bostonman]

I found this 70mph vs 55 mph video very interesting:

• Mach-e select RWD,
• 90F,
• SR 70kwh useable

crazypostman did a 70 mph mileage test on his SR (70kwh usable, 90F) RWD and got ~189 miles range till empty (2.7mi/kwh). He later redid the same test with 55 mph and got >280 miles out of it (almost 50% more range vs 70mph @4.1mi/kwh) - 55mph is painful but might save you a tow if you need extra range to get to the next charging station.

Extrapolate to 62.5mph=235mi range (every -5mph => +30mi range)

 

[Trick.Mach-E]

Going for a helpful response here....

Aero drag does indeed increase with the square of speed.
The best publicly available data for how the Mach-E behaves across a range of speeds is from the EPA fuel economy data, which actually includes a load function vs speed. I used that formula to create the table below, which shows roughly how much your range will decrease with faster speeds. Obviously this is only an approximation, and the numbers would change significantly with cold weather, wind, etc.

I can see our own real world results with your chart. When we took our Mach-E to TX we did a lot of 75-90MPH driving and saw numbers very similiar to what you have posted. On the flip side when we took a leisure drive down the PCH with speeds averaging 55MPH we saw even better than 3.4 kWH.

 

[Scc18603]

Ok so I have to confess and apologize.

My car got a bunch of updates, and my wife and I took it for a 200 mile trip Wilkes-Barre, pa to Hershey, then to Camp Hill and back.

The weather was a warmer, but I had a pretty good wind.

After preconditioning The car actually said 256 on the GOM. First time since delivery.

The car did really well. Hands free wigged out a couple of times mostly on curves between the mountain, but all in good trip down.

2 of the four chargers were down at Chocolate World and the other two had teslas. We then went to the CampHill Mall and the Giant stores have Volta charger. Plugged in and got 40 miles added back while we shopped.

Car made it home with plenty of range.

So maybe my pervious trip experience was due to bad software.

 

[Brian M]

I get using Heat or A/C will have a negative effect on mileage and battery performance. Is there a way to vent outside air into the cabin w/o turning HVAC system on and conditioning air with either heat or a/c. I usually set “heat” to 65 (I like the cold) but MD winters aren’t exactly cold and venting air prevents fogging. Yesterday I turned on HVAC, toggled Heat off, the A/C light was off, the 3 fan lights were off and selected dash vent on. It was about 50f and air was coming through the vents. Is this using battery since the fan is off and air is being pushed in by the speed of the car?

 

[dbsb3233]

I get using Heat or A/C will have a negative effect on mileage and battery performance. Is there a way to vent outside air into the cabin w/o turning HVAC system on and conditioning air with either heat or a/c. I usually set “heat” to 65 (I like the cold) but MD winters aren’t exactly cold and venting air prevents fogging. Yesterday I turned on HVAC, toggled Heat off, the A/C light was off, the 3 fan lights were off and selected dash vent on. It was about 50f and air was coming through the vents. Is this using battery since the fan is off and air is being pushed in by the speed of the car?

I assume by "3 fan lights" you mean AUTO. While AUTO can also make some adjustment to fan speed, it's not the the entire fan speed. When you do any manual adjustments (like turning E-Heat or A/C off), AUTO turns off and I believe you're entirely on the manual 7-speed fan setting.

You were probably still using fan, set to whichever of the 7 speeds you left it at. I doubt there's a way to turn the fan entirely off other than turning climate control completely off. And I think you get no airflow at all then.

At least that's the way I'm remembering. Could be wrong. FWIW, I doubt the fan alone draws much power though. Likely negligible.

 

[JamesStew71]

holy crap, the only way for our Select to manage 3.4 mile/KWh is to drive 65. At 75 it’s down to 2.5.

I have done a few road trips 68 is key speed I get up to 4.4 most of the time , enjoying the ride and cruisin down the highway. You are not getting there any faster anyhow, something will slow ya down. You all know murphy too right

 

[RickMachE]

I had a leg once where for 20 minutes I drove at 55mph to get to the next charger. Speed clearly has an impact.

Currently planning a trip of close to 3,000 miles, multi-day trip, with roughly 20 charges. I did each day/leg in ABRP, imported it into GoogleSheets, made links to each location in PlugShare (where I discovered the need to change some locations because ABRP doesn't know they are being upgraded and not usable), etc. I then added estimated cost, and did some tweaking when a per kWh state borders a per minute state (per minute is about 1/2 the cost) to push charging into states where possible.

Of course the plans will change...

 

[SpaceEVDriver]

I got 2.5 mi/kWh on my way up from California sea level to 7,000 feet elevation going 70-75 mph and keeping the cabin warm. I'm not sure what people do to get lower efficiency.

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