Anyone else getting really weird MPG estimates.

[Skippy477]

I bought my 4xe last week at a dealer about 80 miles from home. When I took delivery there was 10 gallons in the tank (per the dealer) and 75% battery charge. When I got home, I had 88 miles on the odometer and it displayed an estimated 22 mpg. I thought this seemed low, but it was mostly gas driving over that distance and I was going about 70 mph most of the time. Since then, however, I have driven 100% electric and I'm up to 290 miles on the odometer but it still only estimates 26.1 mpg. This is mathematically impossible.

That initial 88 miles at 22 mpg works out to exactly 4 gallons used (assuming it was accurate, which I now doubt). Since then I've driven an additional 192 miles and used 0 gallons. That means the display should show 72.5 mpg (again, assuming the initial MPG was accurate). For me to only have 26.1 mpg, I'd have to have used another 6.8 gallons or a total of 10.8 since I drove it off the lot, but there was only 10 gallons in it so I would have run out of gas by now (I still have half a tank and it hasn't budged since I got it home).

Are they trying to somehow estimate the MPGe of the electric miles? If so, it's pretty annoying and almost certainly of no value since that number is completely made up and varies highly by electric source. Since my electric supplier uses 100% renewable sources my MPGe is infinite anyway.

Sponsored

 

[Ohio Hiker]

how exactly do you quantify a Gallon of electricity?

 

[Skippy477]

how exactly do you quantify a Gallon of electricity?

That's my point. It seems like Jeep is trying to do just that, but it makes no sense.

 

[phobos512]

33.7 kWh of electricity is defined as the energy content of a gallon of gas. No one has yet been able to determine if Jeep is using that to do calculations. I don't know if anyone has actually contacted Jeep yet.

 

[CsD]

The entire system is odd, but I dont sweat it at all as long as my MPG guess keeps going up. I think the oddest thing is that the estimated MPG on hybrid or gas only sits at 250-270 on the 17.2 tank. I chalk it up to not enough time on the Jeep for now. (only 250 miles driven). With that said, I am just under F, and have been charging every night.

 

[asuperheat]

Interesting if a gallon of gas has the same energy as 33.7KWH and you pay say .09 cents per KWH then that would cost you $3.03 for that energy at 100percent efficiency correct or am I missing something?

 

[Skippy477]

Interesting if a gallon of gas has the same energy as 33.7KWH and you pay say .09 cents per KWH then that would cost you $3.03 for that energy at 100percent efficiency correct or am I missing something?

You would pay about the same amount for the energy, but far less of that energy is lost in an electric motor compared to a gas engine. Gas engines only convert about 30-40% of that energy into motion with the rest lost as heat. An electric motor uses nearly 100% of that energy to create motion with almost none of it lost as heat. As a result, the amount you pay for the energy is about the same, but how far you go on it is 2.5-3 times further.

 

[Skippy477]

33.7 kWh of electricity is defined as the energy content of a gallon of gas. No one has yet been able to determine if Jeep is using that to do calculations. I don't know if anyone has actually contacted Jeep yet.

That would make sense. I didn't redo the math using that number, but it is probably in the right ballpark. I would have preferred that only look at actual gallons of gas per mile driven but it's more of a minor annoyance than anything else. It certainly doesn't effect how the vehicle functions.

 

[phobos512]

That would make sense. I didn't redo the math using that number, but it is probably in the right ballpark. I would have preferred that only look at actual gallons of gas per mile driven but it's more of a minor annoyance than anything else. It certainly doesn't effect how the vehicle functions.

I contacted Jeep after I posted that message. Said to myself, why don't we ask them? So I got on chat. They took my info and said a tech expert would be in touch. So, maybe shortly we'll know the no kidding way this works.

 

[Skippy477]

I contacted Jeep after I posted that message. Said to myself, why don't we ask them? So I got on chat. They took my info and said a tech expert would be in touch. So, maybe shortly we'll know the no kidding way this works.

How did you go about contacting Jeep? Are they easy to get hold of?

 

[no.sleep]

How did you go about contacting Jeep? Are they easy to get hold of?

On FCA/Stellantis's website, you can contact them by chat very easily.

Jeep Chat

and then click the black Chat button

 

[pdpardue]

I might be wrong, based on my other car which is also a hybrid, I think it’s just a raw numbers ratio, you’ve driven M miles, and used G gallons, hence M/G… if I drive in electric it still counts the miles which increases the mpg total.

 

[Shasta_Steve]

My way of figuring a conversion for electric "mpg" to gas mpg is to multiply your cost per kw by 15 and that should get your pretty close to and equivalent price per gallon of gas. Not exact but close.

Curious Skippy what utility do you use that is 100% renewable? Did not think any existed yet.

One thing I am curious about is everyone that talks about their MPG is going off the trip computer. I would be very interested in knowing just what it is at the pump. When I first got my f150 the trip computer was saying 23 mpg and when I added it at the pump I was 21.5 mpg.

 

[Skippy477]

I might be wrong, based on my other car which is also a hybrid, I think it’s just a raw numbers ratio, you’ve driven M miles, and used G gallons, hence M/G… if I drive in electric it still counts the miles which increases the mpg total.

That is how I would have expected it to be done (based on my previous vehicle which was also a PHEV), but it definitely isn't how they are doing it.

 

[Skippy477]

My way of figuring a conversion for electric "mpg" to gas mpg is to multiply your cost per kw by 15 and that should get your pretty close to and equivalent price per gallon of gas. Not exact but close.

Curious Skippy what utility do you use that is 100% renewable? Did not think any existed yet.

One thing I am curious about is everyone that talks about their MPG is going off the trip computer. I would be very interested in knowing just what it is at the pump. When I first got my f150 the trip computer was saying 23 mpg and when I added it at the pump I was 21.5 mpg.

I live in PA. We can chose our electric supplier and there are some out there that are 100% renewable (mostly wind power in this part of the country) prices are on par with natural gas and coal powered suppliers. I don't recall off the top of my head who the actual supplier is, it's been awhile since I looked. The bill comes from the PP&L since they own the power lines, but the actual electricity is supplied by someone else and billed through the utility company.

As for the mpg at the pump, I don't know that yet. I haven't had to fill up, and the tank wasn't full when I got it, so it will be a while before I actually have enough info to answer that. So far most of my driving is trips that I can do on 100% electric power but once I have that answer, I'll update it.

Sponsored