How is MPG figured for 4xe

Shasta_Steve

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Okay I understand how to figure MPG in a gas rig. I also understand that MPGe is basically useless unless you are comparing two electric vehicles . I figured that MPG in the 4xe must be the the total miles driven divided by how much gas you used. Basically the same as a normal car.

Well I was watching a Youtube video today where the driver had almost 30 mpg after 100 miles. The thing is he was electric for about 2/3rds of those. So if it was really just gas then they would only be getting about 10 miles per gallon on gas only. I am sure that is not right.

So I am guessing that while driving electric you are given an equivalent MPG to average with your actual gas usage? Something I am missing here? Anyone know just how this is done?
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Sboden

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I plan on taking what my mileage is on my first fill up. I'll then record how much gas I put in at my next fill up and what my mileage is. This number would be my mpg number. I can look at how much electric I use and take that times my rate to roughly get how much I paid in electric. They are separate in my mind. My mpg should be pretty good though that number alone isn't my cost to drive. I'm guessing they are trying to give you a rough MPGe in the car calculation. I could also be talking out of my rear end lol.
 

bjm00se

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There's a couple ways to go.
Old school - keep track of total miles, and total gas purchased. This will average your gasoline usage across all your miles including those powered by plug-in charging. This is a good model if you get electricity basically for free, or you just want to see the impact of reduced gasoline usage.

Alternatively, you can rely on the number reported on the dash. 30mpg in your example above. That'll compute the cumulative mileage while the vehicle is running in gasoline hybrid mode, ignoring any miles driven in EV mode with the gas engine shut off. Because the gas engine turns on and shuts off on demand, you'd basically never be able to calculate this number yourself, and you must rely on the computer to tell you.

So In your example above, it sounds like the second method is used. 100 miles is the total miles driven, but the missing piece of information is the number of miles driven in EV mode -- we get a rough guess "2/3 of the miles." So, it would be a mistake to assume that 3.3 gallons of gasoline were used. If in fact 2/3 of those were in EV mode, then only 1/3 were in gas hybrid mode and the 4xe probably used about 1.1 gallon of gas over that interval. 100 * (1/3) / 30 mpg
 
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Shasta_Steve

Shasta_Steve

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There's a couple ways to go.
Old school - keep track of total miles, and total gas purchased. This will average your gasoline usage across all your miles including those powered by plug-in charging. This is a good model if you get electricity basically for free, or you just want to see the impact of reduced gasoline usage.

Alternatively, you can rely on the number reported on the dash. 30mpg in your example above. That'll compute the cumulative mileage while the vehicle is running in gasoline hybrid mode, ignoring any miles driven in EV mode with the gas engine shut off. Because the gas engine turns on and shuts off on demand, you'd basically never be able to calculate this number yourself, and you must rely on the computer to tell you.

So In your example above, it sounds like the second method is used. 100 miles is the total miles driven, but the missing piece of information is the number of miles driven in EV mode -- we get a rough guess "2/3 of the miles." So, it would be a mistake to assume that 3.3 gallons of gasoline were used. If in fact 2/3 of those were in EV mode, then only 1/3 were in gas hybrid mode and the 4xe probably used about 1.1 gallon of gas over that interval. 100 * (1/3) / 30 mpg
Yeah I am guessing you are right. The numbers just seem a little off to me. If the jeep was able to go 30 MPG in hybrid I am guessing that the battery was helping more than it would if say the battery was nearly empty. I really doubt that the 4xe will get 30 mpg in hybrid only mode. On the other side I really doubt that the Jeep used 3 gallons to go only 30 miles either. I guess I will have to play with it when I actually get it. Another thing I want to see is just how close the trip computer is to real world numbers. I know on my f150 it was always about 1-1.5 mpg better on the trip computer than I got in real life.
 

honeybarreled

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Saw a guy who's owned it a month post in a video on Youtube that he's averaging about 33mpg using the conventional method of tracking how many miles he was covering between fill ups. I would link but I've watched too many videos at this point and no longer remember which.
 

SnB4xe

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If you deplete your battery and never plug in again then you can expect about 20 mpg according to the window sticker.

Our lifetime average on our previous PHEV was 60.5 mpg. 25k miles over 3 years of ownership. As you can imagine, that is mostly short trips near home with time to replenish the battery charge in between trips.

My guess is we will land closer to 30mpg with this 4xe because we plan on driving it into the wilderness 6-8 times/year. But that is just a guess. I really have no idea how we will actually use the vehicle but it will be fun to see what happens.

Keeping an eye for the BEV Wrangler that is promised someday. Am pretty sure we will switch over to that when it becomes available provided it is capablenof meeting our needs and usage.
 

honeybarreled

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Pretty sure the system is set up for passive charging when breaking. Even if you never plug it in to charge, it is ALWAYS a hybrid and will attempt to store charge. I don't believe there's a setting that allows it to never charge the battery, apart from an unofficial one that might be called "broken."
 

SnB4xe

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Pretty sure the system is set up for passive charging when breaking. Even if you never plug it in to charge, it is ALWAYS a hybrid and will attempt to store charge. I don't believe there's a setting that allows it to never charge the battery, apart from an unofficial one that might be called "broken."
Correct. In that Hybrid mode the window sticker says it gets about 20 mpg.
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MaskedRacerX

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There's a number of gauges and instrumentation that show charge, projected mileage, battery vs. gas, average over day/week, plus a neat real-time/animated infographic of how power is being distributed/generated, even has a quick summary when you shut down (the last pic, that's from the dash, the previous 4 are from the uConnect display).

Here's a few from our actual 4xe (the background/UI is pretty slick):

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Skeethree

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Correct. In that Hybrid mode the window sticker says it gets about 20 mpg.
1620341616634.png
I doubt that the 20 mpg figure came from HYbrid Mode as it specifically states “gasoline only”, which I think is E Save mode. After the battery is drained, and running in hybrid mode, I’ve never seen worse than 24 mpg after resetting the tripmeter, and sometimes 28 mpg plus. Keep in mind that figure is a combination of the ICE running plus whatever’s electrical miles you can get from regen.
 

Red4xe

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Just got my first tank of gas this morning. 657 miles on initial tank. Obviously I’m charging nightly (Level 1 for now) and I have a short work commute I can make pure electric. Also, I didn’t realize the 4xe tank is smaller than the standard Wrangler tank.
 

SnB4xe

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I doubt that the 20 mpg figure came from HYbrid Mode as it specifically states “gasoline only”, which I think is E Save mode. After the battery is drained, and running in hybrid mode, I’ve never seen worse than 24 mpg after resetting the tripmeter, and sometimes 28 mpg plus. Keep in mind that figure is a combination of the ICE running plus whatever’s electrical miles you can get from regen.
I've seen the EPA test results. It is hybrid mode, which is what the EPA calls "gasoline only". E-Save doesn't affect the EPA rating unless you check the box that allows the EV portion of the HVB to recharge. In that scenario then it consumes more fuel and results in less mpg.

The EPA test is very specific and doesn't really translate very well to real life. A good driver such as yourself can easily best the EPA numbers with sensible habits. :like:
 

Skeethree

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I've seen the EPA test results. It is hybrid mode, which is what the EPA calls "gasoline only". E-Save doesn't affect the EPA rating unless you check the box that allows the EV portion of the HVB to recharge. In that scenario then it consumes more fuel and results in less mpg.

The EPA test is very specific and doesn't really translate very well to real life. A good driver such as yourself can easily best the EPA numbers with sensible habits. :like:
Well, still getting as much as 29 mpg in hybrid mode after resetting the mpg meter once the ICE kicks on at 1% battery life. I think you’d have to beat the 4xe pretty hard to get down to 20 mpg. Must be those same testers who rate the Wrangler so poorly at Consumer Reports.
 

SLK RCK

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Just got my first tank of gas this morning. 657 miles on initial tank. Obviously I’m charging nightly (Level 1 for now) and I have a short work commute I can make pure electric. Also, I didn’t realize the 4xe tank is smaller than the standard Wrangler tank.
That’s perfect. So 657 miles with XX gallons, XX nights at $2 each and you could figure the equivalent MPG using cost as a basis. That’s what is meaningful unless we’re talking environmental impact.
 
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