4xe actual mileage and range

T-Willy

Well-known member
Jeep states 4xe achieves 49 MPGe in hybrid mode. That claim is repeated here.

But, with a 17.2 gallon tank, its range is 370 miles in hybrid mode--which achieves only ~21.5 MPG.

Many have been led to believe that, under hybrid power and 49 MPGe, the 4xe can travel 49 miles for each gallon of fuel it consumes--which would achieve more than 800 miles on a 17 gallon tank.

Can someone explain this apparent discrepancy?
 
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kootenay

Intergalacticsuperintendent
Where MPGe values come from is like asking how they Caramilk inside the Caramilk bar. Nobody knows it's one of the great mysteries of the universe.

Also the whole MPG is a flawed unit of measure. Gallons per mile makes more sense and ends up being accurate. Why is this important? Having gallons at the bottom of the fraction introduces a huge non-linearity. A single mpg has no fixed value; it isn't a tangible thing.
 
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that_dude

Member
The MPGe rating is calculated by figuring out the number of miles a vehicle can go using the same energy content as a gallon of gas. The EPA calculates that 33.7 kilowatt-hours of electricity is the equivalent to one gallon of gas.
 

T-Willy

Well-known member
The MPGe rating is calculated by figuring out the number of miles a vehicle can go using the same energy content as a gallon of gas. The EPA calculates that 33.7 kilowatt-hours of electricity is the equivalent to one gallon of gas.
And EPA also provides this explanation:

For those vehicles that do not use liquid fuels--such as electric vehicles, plug-in hybrid electric vehicles operating on electricity, and compressed natural gas vehicles-- the labels display miles per gallon of gasoline-equivalent (MPGe). Think of this as being similar to MPG, but instead of presenting miles per gallon of the vehicle’s fuel type, it represents the number of miles the vehicle can go using a quantity of fuel with the same energy content as a gallon of gasoline. This allows a reasonable comparison between vehicles using different fuels. For example, you can use MPGe to compare a compressed natural gas (CNG) vehicle with a gasoline vehicle; even though CNG is not dispensed or burned in actual gallons.

This explanation and yours (thank you) would explain the discrepancy if 49 MPGe were describing 4xe's electric mode mileage, but that's not the case; 49 MPGe is being used to describe its hybrid mode mileage (which, calculated by fuel tank size and range is only actually ~21.5 MPG).

In my opinion, 21.5 MPG would be very underwhelming, especially given the cost and hype.
 
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NatersXJ6

Explorer
I’ve been extremely interested in the 4xe, so I’m paying close attention to the rollout. I don’t really believe the 49 mpge claim. I do however see that the math sort of works, if one applies a dose of sales puffery and a few government charms and crystals. Jeep initially claimed 25 miles in electric only on a 17 kWh battery. Given the 33 kWh per equivalent gallon above, with some rounding, you can get 49 on electric only. I’m guessing that won’t fit my use case.

However, hybrid mileage will probably vary widely with different driving styles and locations.

I can also see a use case where the torque boost from having electric assist available makes a huge difference and allows a wider satisfaction band in many driving situations.

I’ve been to the dealership to see one up close, but the sales guy was a tool, so I won’t be test driving yet! I’m really excited to see what comes out of real world driving.
 

T-Willy

Well-known member
I’ve been extremely interested in the 4xe, so I’m paying close attention to the rollout. I don’t really believe the 49 mpge claim. I do however see that the math sort of works, if one applies a dose of sales puffery and a few government charms and crystals. Jeep initially claimed 25 miles in electric only on a 17 kWh battery. Given the 33 kWh per equivalent gallon above, with some rounding, you can get 49 on electric only.
I found an article that sort of explains it here.

The official EPA electric-range rating for the Wrangler 4xe is 22 miles. That's 3 miles short of what Jeep estimated when the plug-in hybrid SUV was unveiled last year. The Wrangler 4xe also gets an efficiency rating of 49 MPGe combined, and fuel economy of 20 mpg in hybrid mode.

49MPGe = overall combined mileage
20MPG = hybrid-mode mileage

20 MPG is unimpressive for purposes remote touring efficiency and range. You'd be better off with Wrangler diesel.

What a bunch of silly hype.
 

billiebob

Well-known member
Jeep states 4xe achieves 49 MPGe in hybrid mode. That claim is repeated here.

But, with a 17.2 gallon tank, its range is 370 miles in hybrid mode--which achieves only ~21.5 MPG.

Many have been led to believe that, under hybrid power and 49 MPGe, the 4xe can travel 49 miles for each gallon of fuel it consumes--which would achieve more than 800 miles on a 17 gallon tank.

Can someone explain this apparent discrepancy?
yeah, theoretic vs reality
 

billiebob

Well-known member
I’ve been extremely interested in the 4xe, so I’m paying close attention to the rollout. I don’t really believe the 49 mpge claim
Exactly, new technology, wait for real world results before planning that round the world trip on 87 gallons of gasoline. And please forget about a lawsuit when you realize how stupid you were. We are trying to get rational numbers to compare technologies, but no computer geek crunching theoretical data can compare to real world, we need actual owners, overlanders literally experimenting with the theorists theories.

And then you'll add a CB antenna and throw everything into disarray. But even todays fossil fueled cars never actually achieve the EPA numbers unless you are a truly anal hyper miler. In the overlanding world, add a cooler drawing amps plus an RTT LOL and you will need real world data to determine your actual range.

There is no silver bullet. Hyper miling means giving up every creature comfort including shoes and driving barefoot.

There are guys with first gen VW Jetta Diesels who get 70mpg..... but you'd hate to drive behind them.
 
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calicamper

Expedition Leader
All that matters is EV range and combined range in a given terrain etc. My plug-in hybrid does about 12 miles EV only when driven hard-18-20miles when driven like a hyper mile nut.

Depending on terrain, speeds etc full battery and fuel tank I can do 750 miles before needing a refill or 400miles. Just depends how much Electric recovery happens during the drive vs how much is strait up power being put down over x distance etc. EV mode top speed also matters given if EV is basically off at say 30mph then trips at higher speeds are just typical gasser jeep mileage. My Hybrid is EV up to 80mph so a typical 60-70mph trip the EV factor is in play regarding range increases etc.
 
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