Wild MPG variation in hybrid HIGHWAY mpg: Driving style. Ambient temp, both.

[Darryl]

On Wednesday i took a approximately 300 mile trip. Wednesday temp 80 degrees starting out 70 ish at the end... Virtually all highway driving. My 52 year old nephew drove down to Tampa while I mostly slept. He did not use cruise control. And I pretty much hate his driving style. But I was exhausted from a days work. He usually drives mostly below the speed limit and is always varying his speed. It was nerve wracking when I had a Town car. Even moreso in the Maverick with the regen when coasting. As I'd wake and doze off again, I'd see him riding behind a vehicle at 60-65 for a while, then going 70, or so IF he decides to pass. I guess he got tired because the last 70 miles or so he actually fluctuated between 70-80 and even 85. Trip summary: about 34 mpg (vehicle reading) about 42 electric miles. RETURN TEMP 42 start. Approx 35 +/-, I set the cruise to 75 and bumped it up to 78 for 80 miles. Trip summary 27 mpg 4 electric miles (all during the last 20 miles.)

Note that his erratic driving+temp got 9 mpg better than my steady state driving at 30-40 degrees lower temp. I guess the 42 miles of battery driving contributed. But temp contributed also because his past summer I got about 32 mpg at similar speeds. I didn't have much electric power this past summer either. So the internal combustion engine uses more fuel in cold weather too. Yes. Im rambling

Sponsored

 

[vandeda2024]

Could be wind direction too. The Mav isn't exactly aerodynamic, so will be affected by wind quite a bit. And elevation changes if one way is more uphill or downhill.

 

[CurtisB]

Mileage in my 2023 XLT Hybrid goes down considerably when driving long distance at speeds over 72mph. Under 72mph, I get 46-48mpg. Over 72mph, 40mph and the faster I go, I've gotten it down to 38-39mpg.

 

[Surly Old Bill]

MPG gets exponentially worse after about 60mph. Also, I think the varying speed kicks in the electric motor more often.

 

[HeyBales]

MPG gets exponentially worse after about 60mph. Also, I think the varying speed kicks in the electric motor more often.

Nice chart.

Nephew was getting unintentional hybrid pulse and glide - even if perhaps not at the best time.

 

[Cherokee]

“I set the cruise to 75 and bumped it up to 78 or 80 miles. Trip summary 27 mpg 4 electric miles”

At those speeds my Eco would have done an easy 31 mpg on flat land.
I did 29.5 mpg on my last 200 mile haul ass drive to Asheville.

 

[Darryl]

Could be wind direction too. The Mav isn't exactly aerodynamic, so will be affected by wind quite a bit. And elevation changes if one way is more uphill or downhill.

True. No wind either direction. And typically I get the same mileage either direction on this trip. Truth be told, I have noticed that my Ford Focus got significantly less gas mileage on cold days. I drive typically 45 miles each way to work, mostly highway driving. And when it gets near freezing I noticed a few mile per gallon drop even in my old Focus. A lot of fuel economy drop gets blamed on the battery when temperature has more effect on gasoline engines then people realize. I am convinced that the DraStic difference was a combination of all the things, driving style, temperature, and the actual driving speed.

 

[Darryl]

“I set the cruise to 75 and bumped it up to 78 or 80 miles. Trip summary 27 mpg 4 electric miles”

At those speeds my Eco would have done an easy 31 mpg on flat land.
I did 29.5 mpg on my last 200 mile haul ass drive to Asheville.

This was an anomaly. Similar trip 32-33 mpg this past summer . Cruise set to 78-80 mph. I used Texaco gas on the return trip. I guess it's supposed to be good gas. I used gas from WAWA on my way down. But I've noticed with all of my vehicles that some gas seems to just burn through more quickly. I get less fuel economy with flying j gasoline no matter what vehicle I'm driving. Shell seems to do better

 

[Darryl]

MPG gets exponentially worse after about 60mph. Also, I think the varying speed kicks in the electric motor more often.

I think it had something to do with the varying speed since he had 42 electric miles vs only 4 when I drove. Note that I always drive 75-80 on the highway interstate. And this summer I got 32 or a similar trip with two passengers and luggage. And it was 95-100 degrees then

 

[SafetyGuy]

I think it had something to do with the varying speed since he had 42 electric miles vs only 4 when I drove. Note that I always drive 75-80 on the highway interstate. And this summer I got 32 or a similar trip with two passengers and luggage. And it was 95-100 degrees then

Interesting difference in fuel mileage.

With your nephews ummm, unsettling driving style, he sounds like he benefitted from the pulse and glide method as well as drafting behind other vehicles!

I don't draft others on purpose, but when a vehicle passes me and pulls back into the lane in front of me I really feel the difference with both my Mav as well as our camper van. Reduced wind resistance makes a huge difference.

Have a good one,

Andy

 

[gzmn5m]

My 2023 hybrid gets significantly worse mileage when it's cold. I have attributed it to denser air ( more air resistance) and engine running more to make heat for HVAC.

 

[DWV]

70 mph + does not help; but the bigger culprit is use of cruise control- ICE is on more maintaining preset speed with less "coasting". I believe you proved this on your trip. Temp may have some effect but way less than use of cruise. Just my experience from my own driving my 2024 hybrid XL.

 

[Surly Old Bill]

I think it had something to do with the varying speed since he had 42 electric miles vs only 4 when I drove. Note that I always drive 75-80 on the highway interstate. And this summer I got 32 or a similar trip with two passengers and luggage. And it was 95-100 degrees then

I have heard, but haven't researched, that there is a method to driving a hybrid to gain MPG that is different than the driving style to get the most MPG out of an ICE engine. Something about accelerating and coasting to kick in the electric motor.

 

[MaverickDragon]

The drive speed is a large impact, and the average speed increase in the return is likely a big part of the mpg reduction.
With a 40ish degree drop in temperature, the results are not really surprising.

Cold effects the engine, but in the cold, the air is more dense and thus more drag, as well as more energy via the Atkinson to heat the cabin...

 

[Darryl]

I have heard, but haven't researched, that there is a method to driving a hybrid to gain MPG that is different than the driving style to get the most MPG out of an ICE engine. Something about accelerating and coasting to kick in the electric motor.

I believe it. But at 75 mph, it running completely on the internal combustion engine, but it does charge if coasting. Coasting events count as Electric driving. That's probably why a person who drives with his foot on the accelerator may get better fuel economy than when in cruise at high speeds. When we drive, we will automatically decelerate on even slight downhill stretches even though it's subconscious. But no matter the method, cold temps affect fuel consumption even on a non hybrid. The higher the basic fuel economy, the more we notice. A 10 % drop is 2 mpg in a vehicle that gets 20 MPG. But it's a 4 mpg drop in a vehicle that gets 40 mpg. That's why even small things that affect MPG are noticeable on the very efficient Maverick hybrid

Sponsored