Are diesels worth it, for costs per mile?

[mlts22]

Was at a car dealer out of town, and the dealer (name with-held to protect the guilty) was trying to warn me away from a diesel on the 3500 models he was selling, unless I had at least $15,000 a year stashed away for maintenance costs.

After looking at various forums and reading about problems people have (from fuel in the oil, to fuel filters failing and blowing the engine, to ECM issues, to injectors (at $500 each on average), to cracked DPFs, having to replace the high pressure fuel pump every 5000 miles (about a grand) to being stranded since the vehicle's computer won't allow the vehicle to start due to no DEF (even if the tank is full.)

I have a feeling a lot of it is just bad luck and statistically, there are a lot of diesels out there, so seeing issues is not surprising.

In people's opinions, are the maintenance horror stories for a diesel just way blown out of proportion?

If there is some credence, should I go for an extended warranty if I buy a diesel vehicle, just so I don't end up stranded and $2500 lighter because a high pressure fuel pump decided to call it quits. I do know that the recent EPA regulations have caused reliability problems, but I'm wondering if truck makers finally have the kinks worked out.

-quick edit- Apparently the guy who said the $15k figure per year is no longer at the dealer in question, so that explains a lot.

[blt2ski]

# pages of stuff that is also said in the above sticky D vs G! yeah, so take it up there thank you!

As one can see, this question is like ones rear end, All have answers, all stink, all opinions count etc etc. THere is NO correct answer as one can also see!

Marty

[45Ricochet]

Turtle n Peeps wrote:

Halle-freaking-lujah!!!

I know my truck with 200HP and 425 of torque and 15K gross is down to about 30MPH on some steep grades. And before anybody say's it; it has 4:10 gears and stock tires. As stated above, it would not make hardly any difference anyway. And before anybody says it again, no, gears don't make power. Although it would be cool if they did. :B

Dang I should have ask you before I bought my TV back in 2006. Guess I should have bought this HP king for towing, since it has more HP :B



Guess the DW and dog could ride in the fiver :W
Again it's a combination of TQ, HP and gears. Not one single item trumps the others IMO.

[waynec1957]

Taco wrote:
It is hard to justify a diesel on numbers alone. There is no one size fits all answer some people will come out dollars ahead with diesel and others with gas.

However the diesel will get 2-3 mpg better than gas and tow at 1800-3000 rpm instead of 2500-5000 rpm that a gas truck will. If you put your foot to the floor towing up a grade with the gas and the diesel they will climb within a few mph of each other with a slight edge to the diesel.

To some people the 8-10k upfront cost of a diesel that some of which may be gotten back at resale is worth it for the lower rpm towing and better mpg.

However be advised that while 15k a year for maintenance is nowhere near accurate that there is a chance that the diesel truck will have an engine problem that may not be covered by warranty that can run from 10-20k to repair. So a buyer does need to consider if they would be able to handle a 10k+ repair bill even if the chance is pretty small.

I didn't have to put my foot on the floor to get up a grade, at least not in the Smokies. All I did was set the cruise and the truck did the rest. :B

I plan to keep this truck until one of us turns to dust so I bought a 10 year extended warranty upfront for about $2k.

[Taco]

It is hard to justify a diesel on numbers alone. There is no one size fits all answer some people will come out dollars ahead with diesel and others with gas.

However the diesel will get 2-3 mpg better than gas and tow at 1800-3000 rpm instead of 2500-5000 rpm that a gas truck will. If you put your foot to the floor towing up a grade with the gas and the diesel they will climb within a few mph of each other with a slight edge to the diesel.

To some people the 8-10k upfront cost of a diesel that some of which may be gotten back at resale is worth it for the lower rpm towing and better mpg.

However be advised that while 15k a year for maintenance is nowhere near accurate that there is a chance that the diesel truck will have an engine problem that may not be covered by warranty that can run from 10-20k to repair. So a buyer does need to consider if they would be able to handle a 10k+ repair bill even if the chance is pretty small.

[rwjejits]

billyjoeraybob wrote:
IMHO if you can afford to purchase the diesel truck, after your first trip towing a camper, you will never look back!

x2

[jus2shy]

Tom_M wrote:

N-Trouble wrote:
As far as the previous comment about diesel engines being much simpler than their gas counterparts may have been the case 10+ years ago, but no longer thanks to all the emissions and computer controls associated with them. Emissions controls are where most of the problems exist with todays diesels and they can be quite frustrating for some owners. Hence why so many rip them off and run a delete tune.

A diesel engine has never been simpler than a gasoline engine. You are basically taking away a simple electrical ignition system and replacing it with a very high pressure fuel pump/fuel distribution system. Because of the high compression ratio you now need a huge starter and probably two batteries.

The main reason for diesel is the greater torque it provides thus exceptional towing capability.

I beg to differ. Back in the 90's, you still had crank driven mechanical pumps versus electronic fuel injection systems. The mechanical pumps were always timed with the engine (just like a timing set on old timing chain blocks). And the pump system simply had a plunger for each injector. So high pressure was supplied to the injectors like clock work. Once the pump was set, you never had to fool with it. Engines back then had all sorts of sensors for the fuel injection system. Had to figure out mass airflow and time the spark ignition depending upon throttle demand and all sorts of other items. This was a time when diesels were much simpler motors.

Now with today's motors. I'm torn on figuring out which one is simpler. Diesels now a days have nearly the same sensor suite as gasoline motors. However, gas motors do need to rely more on the sensors to maintain proper combustion where as diesels don't care about ratio so much unless it effects emissions (then the EGR or regen steps in at that point). Gasoline engines still have an ignition system (that everyone claims is simple, it is an additional system that is non-existent on a diesel). However, both have a fuel system that at times includes high pressure fuel pumps (gasoline motors are going direct ignition as well). Yes you need a bigger starter, but it isn't any more complex. And not all diesels require 2 batteries (depends on starting method, glow plugs or grid heater, etc...). The other argument of turbochargers and intercooler are also moot. One need only mentions "Ecoboost" and it's a level playing field. As in theories of operation, I would think a gasser motor is more complex in that it has a narrower operating range compared to a diesel (Diesels just need fuel added at the right time to function, gas motors need to maintain a narrow operating ratio in order to ensure proper combustion along with spark). So it becomes a pain to diagnose why you have a rough running condition. The only thing that gassers have far simpler is the emissions system. No DPF there, no NOx SCR system there either. So I figure that balances out the lack of ignition system on the diesels. In the end, it really is a wash in my book. But the saying that there is potential for very expensive repair is certainly true on a diesel. Parts costs are higher on a diesel, like for fuel injectors or the HP fuel pump (which costs 2x or more than a HP fuel pump on a GDI motor). But those parts typically are designed to last a minimum of 250k miles or more.

As for me, I prefer a diesel. I get close to 20k miles a year, diesel is 10 or more cents per gallon cheaper in my parts versus regular unleaded. I do my own maintenance and I spend roughly $150 more a year on maintenance. But that is made up within 6 weeks of driving for me. Then I'm further ahead as I move on. I also happen to have a deal where my current diesel RAM was $5,000 cheaper than my 2010 Ford F-150. My RAM actually has a few more features than my F-150 had. So if you can find a deal where you come out ahead on a diesel. Weigh the fuel costs and fuel economy benefit, then it may work for you. Depending on where you live, you can save, or you may pay more to own a diesel. In my case, I saved all around.

[Turtle_n_Peeps]

wnjj wrote:

rhagfo wrote:
Last to the Gas guy's that say HP is everything, please explain to me, how 270 HP tows 11,000# (19,000# GCVW) at 60 mph up 6% and 7% grades, with 3.55 gears?

Simple:

1) It takes less than 270 HP to do that.
or
2) Your engine is producing more than 270 HP.


Look at the chart on page 7 here. It's written by Caterpillar and they likely know a thing or two about HP and torque.

Anyway, they show that climbing a 6% grade at 55mph takes about 10hp per 1000 lbs plus the wind resistance. Their example uses coaches but a truck & trailer isn't far off.

So, 19,000 / 1000 * 10 = 190HP plus another 60 for wind and you're at 250HP. Now 60 mph will take more but it's quite possible your engine is putting out more than 270 HP too.

Rear gears are not relevant unless they put your engine out of its best power generating RPM.

Halle-freaking-lujah!!! Woo hoo, someone else that gets it. Post of the year and should be a sticky! 🙂

I know my truck with 200HP and 425 of torque and 15K gross is down to about 30MPH on some steep grades. And before anybody say's it; it has 4:10 gears and stock tires. As stated above, it would not make hardly any difference anyway. And before anybody says it again, no, gears don't make power. Although it would be cool if they did. :B

[wnjj]

rhagfo wrote:
Last to the Gas guy's that say HP is everything, please explain to me, how 270 HP tows 11,000# (19,000# GCVW) at 60 mph up 6% and 7% grades, with 3.55 gears?

Simple:

1) It takes less than 270 HP to do that.
or
2) Your engine is producing more than 270 HP.


Look at the chart on page 7 here. It's written by Caterpillar and they likely know a thing or two about HP and torque.

Anyway, they show that climbing a 6% grade at 55mph takes about 10hp per 1000 lbs plus the wind resistance. Their example uses coaches but a truck & trailer isn't far off.

So, 19,000 / 1000 * 10 = 190HP plus another 60 for wind and you're at 250HP. Now 60 mph will take more but it's quite possible your engine is putting out more than 270 HP too.

Rear gears are not relevant unless they put your engine out of its best power generating RPM.

[Wes_Tausend]

...

I am one diesel owner that is not entirely happy with owning a diesel.

I think we all can see you would like a diesel, so you might as well get one. There is nothing wrong with getting one as a hobby type purchase unless it will be a burden on your families budget, or the premium price sticks in your craw. I've known guys that gave up a decent, reliable vehicle for their wife and kids, just so they could own a prestigious personal truck, and I don't have much respect for that. But that doesn't sound like you and it wasn't me.

I don't think even the marginal greater expense of diesel pickups are very practical for 98% of RV owners, but many enjoy the wow performance of diesel/gas turbocharged engines, since they seem to have more power due to running in their peak torque range at normal highway speeds. When not turboed, diesels are underpowered dogs too, typically worse than gas. Some of the newest turbo-diesels do exceed gas hp offerings.

Regarding my diesel dissatisfaction, I was going to buy an older '95 Cummins powered Dodge because I did calculate that I could save money with it. The expected cost was $8k stock and it ran like a top, got great towing economy and had just over 100k miles on it. Since it had a five speed and the clutch had never been abused, ball-joints were good, I assume it would have likely been trouble-free. In a few years I would have sold it stock for the same $8k and pocketed the fuel savings.

The downside, it was a standard cab. And got traded out from under me because I did not clearly make my willingness to buy, known beforehand. Shouldn't have been so shy.

So, affected by the fever, and not trusting other Dodges in that price range, I bought a 2000 F-250 on a whim instead. The upside was a crewcab, excellent body, new tires and balljoints, and a more reliable automatic tranny per DW's wishes. The downside was 131k miles, slightly less fuel economy, just as noisy and nearly twice the cost. It is highly likely I'll never break even on resale vs purchase price, and my larger dent in savings haunts me. The truck pulls good and holds OD better, but it is still not anywhere near as snappy, and quiet, as our V-10 Excursion. Towing fuel economy is about 8 mpg gas, or 11 mpg diesel. I'll never make up the extra diesel cost by fuel savings, but maybe the early F-250 operation will grow on me more later. It is too late to go back now.

Wes
...

[fla-gypsy]

It's not worth it to me and that's all I need to be concerned about. A couple of oil changes a year at $30+ and some scheduled maintenance at very long intervals. It has never needed any real repairs.

[waynec1957]

I bought the truck in my signature last November. Over the winter, doing the same driving I had with my 1/2 ton I was spending right at $15 more per week for fuel. With just under 5,000 miles on it the mpg was 14 city/ 19 highway unloaded.

At 7,500 (give or take) miles I've spent $75 on an oil change and $35 for DEF fluid (and $14 to have the tires rotates). I'll do that again by fall plus replace the fuel filter.

We towed our 6,000 lb (loaded) camper through Kentucky into the Smokies and back about 4 weeks ago. Averaged 12.5 mpg for the whole trip running (mostly) 65 mph. And this truck isn't anywhere near broke in.

Here's the thing with me. I tried to justify the additional cost of the diesel up front when I was having this debate with myself and never could. BUT, having owned it now for a while and pulled (light as it may be) out TT over 1,000 miles, I would never look back. With THIS camper, I never knew it was back there. Sooner or later we're going to a much bigger camper and we'll see what happens then.

What I've come to realize, the cost per mile is not what's so attractive about a diesel (for me). When I hit the mountain at Jellico Tennessee on I 75 (all right, it's not the Rockies) the truck never missed a beat. Cruise set at 65 mph and it stayed there all the way to the top...at under 2,000 rpms. Set the cruise at 60 coming down (wanted to see what it would do) and it never accelerated above 62 mph and only then for a few seconds. And I didn't have to listen to the engine whine all the way up and down.

Here's the kicker. At the end of the day, when we got to our destination, I wasn't worn out. THAT is why I bought the diesel.

[JIMNLIN]

op says wrote:
The main reason I'm looking at a diesel is for hitting Colorado. Any of the Big Three have a turbo diesel engine that will lose a lot less power when at higher elevations compared to a gasser (the Ford's EB is the exception because of the added boost.)

Looking at your profile shows a 25' trailer. You sure don't need a diesel to pull that small trailer in the mountains.
I used a '84 1/2 ton chevy and pulled a brand new 1984 26' 7680 GVWR small fiver all over CO/NM mountains for several summers.

Now if your moving up to a 14k-15k trailer in the future then the diesel will shine.

The newer gas engines such as the 6.4 Hemi with its 410 hp and around 420 ft lbs torque won't have any issues in the mountains pulling 10k + lb trailers.

Also the older 8.1 GM big block and Fords V-10 gas engines have even more torque for towing heavier trailers if your looking at used trucks.

[Old-Biscuit]

Are diesels worth it, for costs per mile? .........NO

Unless you are towing or driving a small diesel car


Would I go back to a gasoline vehicle.......
Only if I ever gave up towing and then it would be a gas eating tire smoking slammed back in your seat one.

[Drew_K]

From a purely financial perspective, I think it's pretty hard to save money from a diesel. Yes, you will save on fuel costs if you tow a lot, but that will is offset by the fact that the diesel costs more to begin with (an $8K option for Ford trucks) and the maintenance costs are slightly higher. I do recognize that you will recoup some of the added cost of the diesel engine on resale.

So my take has always been to buy a diesel because you need it or want it, but financial justification is pretty hard unless you tow A LOT of miles.

The water in fuel thing can be catastrophic but keep in mind that the truck does have a water/fuel separator. It will only separate so much water but it's not as if the engine will detonate because of a little water.

A couple of practical advantages to having a diesel: The ability to fill up at truck stops, which is a big plus in my view. You also have the ability to add an auxiliary fuel tank and/or replace the stock one to greatly increase your range before having to refuel. VERY convenient.