Rough draft: Cost analysis of Diesel Wrangler

[miklm]

Here's a mix of some real world data combined with speculation, since MPG has not been announced (much less any real world MPG which will differ from the EPA numbers)

I have a gas JLUR and a diesel pickup (Silverado 2500) so I have good data on fuel prices in my area. I'll limit my data to the previous 6 months, since that's how long I've owned my Jeep. In that time, the average cost of gas (Regular/87) I've paid is $2.32/gal and for diesel I've paid $2.78/gal. That's a 20% premium for diesel fuel.

Assuming all other costs being equal (maintenance/repairs) - which is not true as the diesel engine will require DEF, more frequent fuel filter changes, possibly more expensive engine oil, and maintenance/repair costs, especially out of warranty, are unknowable... but assuming all that being equal to the 3.6L gas w/ auto:

Over 8200 miles, I'm averaging 17.77 MPG (actual hand calculated, more accurate than OBC numbers) on a stock JLUR with roughly 75% highway/25% city driving. At $2.32/gal, my average cost per mile is $0.1306 (this is the number used in the following chart for comparison)

Now, we know the diesel engine is a $6,000 option ($4k engine + $2k trans) but that's only a $3250 premium over 3.6L with auto. Assuming the buyer who is this conscious of fuel cost/savings would also be a somewhat shrewd negotiator, I'm going to take 10% off that $3250 and use $2925 as the "out the door" cost premium paid for the diesel engine. That's probably the best-case scenario.

So, how long until you recoup that cost premium? What MPG will you need to get? Remember, you have to make up the engine option cost plus the 20% diesel fuel premium. Here's a quick chart:


Avg price/gal Avg MPG Avg price/mile Option cost Miles to recoup
$ 2.78 22.00 $ 0.13 $ 0.00419 2925 697,510.98
$ 2.78 24.00 $ 0.12 $ 0.01472 2925 198,658.15
$ 2.78 26.00 $ 0.11 $ 0.02363 2925 123,762.16
$ 2.78 28.00 $ 0.10 $ 0.03127 2925 93,535.93
$ 2.78 30.00 $ 0.09 $ 0.03789 2925 77,196.23
$ 2.78 32.00 $ 0.09 $ 0.04368 2925 66,961.04
$ 2.78 34.00 $ 0.08 $ 0.04879 2925 59,947.84

So, best case, you get 34 MPG (yeah right) you're looking at 60,000 miles to break even. More realistically, I'm guessing 24-26 MPG is going to be the high end in real world conditions, meaning it will take between 125-200k miles to make up the premium paid for the diesel in the best case scenario.

I'll have to let someone else do the calc on the gas 2L turbo since I don't have real MPG data from that engine and I honestly don't even know what it costs vs. a 3.6L

Just some data to chew on. There obviously may be other reasons a customer would prefer the diesel engine, but I would be skeptical based purely on a MPG/fuel economy/cost savings standpoint. Discussion and any corrections are welcome, as I pulled this together rather quickly and may have made a calculation error somewhere. Thanks!

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[JLURD]

Here's a mix of some real world data combined with speculation, since MPG has not been announced (much less any real world MPG which will differ from the EPA numbers)

I have a gas JLUR and a diesel pickup (Silverado 2500) so I have good data on fuel prices in my area. I'll limit my data to the previous 6 months, since that's how long I've owned my Jeep. In that time, the average cost of gas (Regular/87) I've paid is $2.32/gal and for diesel I've paid $2.78/gal. That's a 20% premium for diesel fuel.

Assuming all other costs being equal (maintenance/repairs) - which is not true as the diesel engine will require DEF, more frequent fuel filter changes, possibly more expensive engine oil, and maintenance/repair costs, especially out of warranty, are unknowable... but assuming all that being equal to the 3.6L gas w/ auto:

Over 8200 miles, I'm averaging 17.77 MPG (actual hand calculated, more accurate than OBC numbers) on a stock JLUR with roughly 75% highway/25% city driving. At $2.32/gal, my average cost per mile is $0.1306

Now, we know as of today the diesel engine is a $6,000 option ($4k engine + $2k trans) but that's only a $3250 premium over 3.6L with auto. Assuming the buyer who is this conscious of fuel cost/savings would also be a somewhat shrewd negotiator, I'm going to take 10% off that $3250 and use $2925 as the "out the door" cost premium paid for the diesel engine. That's probably the best-case scenario.

So, how long until you recoup that cost premium? What MPG will you need to get? Remember, you have to make up the engine option cost plus the 20% diesel fuel premium. Here's a quick chart:


Avg price/gal Avg MPG Avg price/mile Option cost Miles to recoup
$ 2.78 22.00 $ 0.13 $ 0.00419 2925 697,510.98
$ 2.78 24.00 $ 0.12 $ 0.01472 2925 198,658.15
$ 2.78 26.00 $ 0.11 $ 0.02363 2925 123,762.16
$ 2.78 28.00 $ 0.10 $ 0.03127 2925 93,535.93
$ 2.78 30.00 $ 0.09 $ 0.03789 2925 77,196.23
$ 2.78 32.00 $ 0.09 $ 0.04368 2925 66,961.04
$ 2.78 34.00 $ 0.08 $ 0.04879 2925 59,947.84

So, best case, you get 34 MPG (yeah right) you're looking at 60,000 miles to break even. More realistically, I'm guessing 24-26 MPG is going to be the high end in real world conditions, meaning it will take between 125-200k miles to make up the premium paid for the diesel in the best case scenario.

I'll have to let someone else do the calc on the gas 2L turbo since I don't have real MPG data from that engine and I honestly don't even know what it costs vs. a 3.6L

Just some data to chew on. There obviously may be other reasons a customer would prefer the diesel engine, but I would be skeptical based purely on a MPG/fuel economy/cost savings standpoint. Discussion and any corrections are welcome, as I pulled this together rather quickly and may have made a calculation error somewhere. Thanks!

Someone ought to make a tool into which one can enter their typical price delta between 87 and diesel because it varies by a LOT across the country. For example, I pay about $0.05/gallon less than 87 throughout the year. Vastly different scenario than what you’re stuck with.

 

[Hudson]

I did the same analysis when I bought my RAM 2500, except the diesel option added $7k over the gasser. On paper, it never seemed to pencil out unless I drove many miles.

I’ve never regretted the diesel, especially when on road trips I have a 550 mile range, or ascending passes, passing cars when I have 2 dirt bikes in the back while towing an 8000lb RV. I liked the diesel experience so much I bought my missus a diesel version of the BMW wagon. It gets 42 mpg on the highway and pulls like a freight train. It was about 3k more than the gasser.

You should factor in resale, as diesels command a much better resale. But agree, it never looks like a wise economic choice, but ask most diesel owners and they will never regret their choice. If they made the 2 door with a diesel, I would opt for it.

 

[miklm]

Someone ought to make a tool into which one can enter their typical price delta between 87 and diesel because it varies by a LOT across the country. For example, I pay about $0.05/gallon less than 87 throughout the year. Vastly different scenario than what you’re stuck with.

Great point. I could do it in a spreadsheet very quickly, but making a web tool would take more time that I don't have. Here's my spreadsheet (attached) if that helps you any.

 

[CarbonSteel]

[...] Just some data to chew on. There obviously may be other reasons a customer would prefer the diesel engine, but I would be skeptical based purely on a MPG/fuel economy/cost savings standpoint. Discussion and any corrections are welcome, as I pulled this together rather quickly and may have made a calculation error somewhere. Thanks!

The maintenance costs have to be considered as well, although I have no knowledge of a FCA diesel, I will assume like most modern diesels, the oil quantities are about double that of a gasoline engine and the fuel filter(s) and oil filters cost more. There is also the DEF cost to add to the pile.

As you said, for most, it will not break even until 60K+ (I am betting 100K+) miles are driven and that is minus any frustration/aggravation factor if there are issues.

 

[CarbonSteel]

Someone ought to make a tool into which one can enter their typical price delta between 87 and diesel because it varies by a LOT across the country. For example, I pay about $0.05/gallon less than 87 throughout the year. Vastly different scenario than what you’re stuck with.

Indeed; in the Houston area, 87 octane gasoline is typically $2.19 per gallon where as diesel is $2.59 so there is a negative $0.40 delta per gallon from the start.

 

[miklm]

Indeed; in the Houston area, 87 octane gasoline is typically $2.19 per gallon where as diesel is $2.59 so there is a negative $0.40 delta per gallon from the start.

$0.46/gal higher for diesel is what my figures use based on pump prices over the last 6 months, mostly between Birmingham AL and Atlanta GA. Very close to what you see in Houston, and that delta is similar to what I see in travel to other parts of the lower 48. if diesel is cheaper in Alaska, it is truly an outlier as that is not the case in the continental US, since Low sulfur/ULSD were mandated around 2007-ish

 

[Almost]

I did some rough math the other day as well and I got similar numbers, but I have a 3.8 JK which does even worse on gas. I calculated $0.149 per mile for my 3.8 JK vs $0.107 for the eco diesel. It came out to a 28% reduction in fuel costs. Based on my average mileage of 18K per year I would save $755 per year based on fuel costs today and it would pay for itself in just under 4 1/2 years. This was assuming 28 mpg for the eco diesel, which I think is reasonable given our diesel GC got 28 on the highway and the gen 3 motor is even more efficient (diesel 1500 went from 27 to 30 mpg on the highway).

 

[JP18]

Fuel only:

2018 JLUR (V6/6MT): $0.11/mile
2015 GC (8AT) Ecodiesel: $0.10/mile

JP18

 

[toolaide4fit]

I did the same analysis when I bought my RAM 2500, except the diesel option added $7k over the gasser. On paper, it never seemed to pencil out unless I drove many miles.

I’ve never regretted the diesel, especially when on road trips I have a 550 mile range, or ascending passes, passing cars when I have 2 dirt bikes in the back while towing an 8000lb RV. I liked the diesel experience so much I bought my missus a diesel version of the BMW wagon. It gets 42 mpg on the highway and pulls like a freight train. It was about 3k more than the gasser.

You should factor in resale, as diesels command a much better resale. But agree, it never looks like a wise economic choice, but ask most diesel owners and they will never regret their choice. If they made the 2 door with a diesel, I would opt for it.

You are correct. It is really easy for me...I own a Chevy 2500 HD Duramax and I have a $650 programmer on it and get 20 MPG on the highway. It doesn't take a tool to figure out I will save 30% on Diesel buying a Diesel Jeep. The new Diesel will get 30 MPG. My truck is worth a stupid amount of money! It doesn't have the BlueDef and it will easily sell for $6k to $8k over a gasser and it is 13 years old. Don't know if I will sell it, but I could make a pretty penny. So for ME, it will save on the cost of Diesel...but more importantly it is what I want and I don't care what it costs.

Not knocking anyone, but Jeeps are great but if you want to save money and don't get a Jeep. Get a Prius! Because you will make modifications to your jeep and you will spend a stupid amount of money. It is for my pleasure! Lol!

 

[JLURD]

$0.46/gal higher for diesel is what my figures use based on pump prices over the last 6 months, mostly between Birmingham AL and Atlanta GA. Very close to what you see in Houston, and that delta is similar to what I see in travel to other parts of the lower 48. if diesel is cheaper in Alaska, it is truly an outlier as that is not the case in the continental US, since Low sulfur/ULSD were mandated around 2007-ish

We run the mandated ULSD here but the state doesn’t tax the hell out of either gas or diesel so the prices reflect a production, shipping, and federal excise taxes, rather than rampant state manipulation/theft. I’ve also lived in areas of the northeast where diesel runs around the cost of 87 in the Summer, 91 in the Winter (home D2 heating oil demand drives diesel prices higher).

 

[NFRs2000NYC]

Who the hell would buy a diesel wrangler to save money? If you're trying to save money, you're buying the diesel for the wrong reasons

 

[JLURD]

Great point. I could do it in a spreadsheet very quickly, but making a web tool would take more time that I don't have. Here's my spreadsheet (attached) if that helps you any.

Thanks. For comparison, including my price per mile for DEF and the delta for oil/filter costs running the 3.0, the up-front cost is paid for by 66,000 miles assuming I get 24mpg rolling 37s and a 2.5” lift. That’s all good and well but the upsides of range and torque would have me sold even if it never saved me a dime.

 

[Frostbit]

You are correct. It is really easy for me...I own a Chevy 2500 HD Duramax and I have a $650 programmer on it and get 20 MPG on the highway. It doesn't take a tool to figure out I will save 30% on Diesel buying a Diesel Jeep. The new Diesel will get 30 MPG. My truck is worth a stupid amount of money! It doesn't have the BlueDef and it will easily sell for $6k to $8k over a gasser and it is 13 years old. Don't know if I will sell it, but I could make a pretty penny. So for ME, it will save on the cost of Diesel...but more importantly it is what I want and I don't care what it costs.

Not knocking anyone, but Jeeps are great but if you want to save money and don't get a Jeep. Get a Prius! Because you will make modifications to your jeep and you will spend a stupid amount of money. It is for my pleasure! Lol!

My fully mechanical 1996 Cummins 12V is worth more now than I paid for it used in 2000.

 

[toolaide4fit]

Who the hell would buy a diesel wrangler to save money? If you're trying to save money, you're buying the diesel for the wrong reasons

I say buy what you want and what you can afford. Buying a jeep, no matter the power plant, it isn't going to save you money in the long run. You have to wait 50 years and hope you buy the right vehicle and it becomes a collectors item to make money.

I buy mine to drive and what makes me happy!

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