Diesel vs. Gas

[GrantRobertson]

I am sure this has been discussed at length, spread out over lots of different threads. However, I could not find a thread devoted to this specific topic. So...

Diesel vs. Gas: What are the pros and cons?

My particular situation: I plan to convert a small shuttle bus to an "RV." What will essentially be a larger version of a van retrofit. My build will not weigh nearly as much as many complete RV type conversions. However, I may want to pull a trailer in the future. These shuttle buses come in gas and diesel varieties, all of which have a lot of miles on them.  Here are the differences as I see them. Feel free to correct me if I am wrong:

1. Diesel has more torque for pulling heavier loads up hill.
2. For the equivalent sized engine, diesel gets better gas mileage. However, if diesel costs too much more than gas, then that difference doesn't save you much or any money.
3. Diesel engines last longer.
4. However, diesel engines cost more to fix.
5. Diesel mechanics are few and far between, possibly leaving one stranded in a diesel mechanic no-man's-land.

And here are some of my questions:

• Is it too terribly much harder to learn how to work on a diesel engine? I have always had a pretty easy time working on gas engines. I'm not a massively experienced mechanic but I can read a manual and look stuff up on the internet and then do as well or better than most.
• I'm primarily looking at Ford E-series based shuttles, though I would consider a Chevy or a GMC. Are the parts for Ford E-series diesel engines as easy to find as parts for the gas engines?

P.S. In consideration of future readers, let's please keep this thread on only the gas vs diesel topic. I will start other threads to discuss my build, why I chose a shuttle, etcetera.

 

[Fabber McGee]

If you decide to go with a diesel, you should stay away from the more modern computerized fuel systems built since the mid 90's. Not because they are terribly difficult to understand, anyone that is interested enough can study how they work and be able to diagnose problems and they do provide slightly lower emissions levels.


The big drawback is the cost of parts. I have a 7.3 with electronic injection in a 97 Ford pickup that is totaled for the price of parts even though the engine is far from being worn out. It has a little under 300,000 miles on it and needs a full set of injectors and a high pressure pump. Parts cost around 2500.00 for rebuilts with exchange. I also have a rusted out 1990 Ford with a good strong 7.3 that uses mechanical injection that will be swapped in as soon as I get the time. I can get a full set of mechanically controlled injectors  for less than 200 bucks when the need arises and an injector pump is in the neighborhood of 500. Plus, no computer or expensive relays and such to replace ever.

BTW, diesel is currently about 30 cents cheaper than gas in my area.

Just my 2 cents worth.

 

[GrantRobertson]

If you decide to go with a diesel, you should stay away from the more modern computerized fuel systems built since the mid 90's.

The big drawback is the cost of parts.

So, are parts for modern has engines not also a lot more expensive than for older has engines. Or is it just that modern diesel parts are proportionally far more expensive?

 

[GrantRobertson]

One additional reason I am considering diesel is the increased options for alternative fuels. Diesels can use biodiesel and can be modified to take vegetable oil.

I am also very interested in wood gas. I have read that the computers in modern diesels automatically adjust if you start piping wood gas into the intake, with no modifications necessary. The more wood gas you pump in, the less diesel is injected.

 

[Optimistic Paranoid]

Grant, based on what you said in your original post, if I wuz you, I'd go buy a diesel repair manual and study up on it before making my decision.

Here's a couple of not very expensive examples, there are others.

http://www.amazon.com/Troubleshooti...133370&sr=1-3&keywords=diesel+engine+textbook

http://www.amazon.com/Diesel-Genera...sr=1-5&keywords=diesel+engine+repair+handbook

Regards
John

 

[MikeRuth]

If you want tough and pulling power then diesel. Spend what ever it takes to get it up to snuff and solid and you got a winner. Like the others said pre computer is preferred.

BTW diesel mechanics are about as far away as you can throw an injector, lest you not forget that trucks are running all over this country running a diesel engine.

I'm a gas guy, it's what I have and what I'm sticking with.

My 2 cents

 

[highdesertranger]

my 2 cents. diesel is the most efficient internal combustion engine by far. meaning it turns fuel into useable energy better than anything else by far.

diesel has been cheaper than gas in CA for years and you know what they say as goes CA so goes the nation.

like others have said old mechanical diesels are far more reliable and easier to work on.

the only good Ford diesel is the 7.3 all others are junk.

diesel mechanics are everywhere, all heavy trucks are diesel, all agriculture equipment is diesel, all heavy construction equipment is diesel, all heavy mining equipment is diesel, ships are all diesel. notice a pattern here there is a reason for this. btw I am getting ready to convert my truck to diesel. highdesertranger

 

[Spirituallifetime]

Even at higher prices for diesel fuel it is still cheaper to run than a gas engine. I think diesel cars didn't really take off because of the higher price for diesel, people assumed it would cost more to run than gas.
And most diesel engines before 2003 were reliable. After 2003 there were many problems with them when the EPA mandated the manufacturers to cleanup the exhaust on diesel engines, these newer engines are less reliable and cost more to maintain.

 

[eDJ_]

About what year Shuttle Bus are you considering ?   If it is earlier 90's and pre electronic/computer control you may  be looking at a "mechanical diesel".  So it would be within your reach to do a lot of the work yourself.

The most complicated systems on the diesel are the injectors and the fuel pump.  The rest is similar to the
gasoline engine.

Are you considering keeping the original engine or retro fitting to an after market engine ? 

I was reading recently the reviews of Perkins (UK now owned by Cat),  Kubota (Japan), and Deutz air diesel (Germany).   A new Perkins diesel were thought to give about 10,000 hours of trouble free service and very
smooth operating.   The Kubota may get 7,500 hours but is a steel sleeved aluminum engine, thus light weight.  It isn't thought to be as smooth in operation.  The Deutz air diesel with a preheater installed starts very easily in cold weather.  It's rugged.  These can be had in 4 , 6, and V8 cylinder. 

Thus you can have an older style mechanical diesel vehicle.  You won't need all kinds of computer equipment to  work on that as you would the later systems with computers etc.

The climate you are in may drive your choice of diesel or gasoline engine.  Diesels don't always start easily
or run well in cold weather unless purpose fitted for that application.  (intake heaters, fuel tank heaters, and shutter stats or winter fronts on the radiators)

But there is a lot to this question.   More information may be helpful. 

These are my 2 cent thoughts.

 

[GrantRobertson]

The shuttle I want is a 1999, E350 with a 7.3 V8 diesel, for $4,000.

There is also a 2003, E something with a 6.8 V10 gas, for $4,500. But it has a wheelchair lift, which I don't want.

There are several more but they are all larger than I need / want.

 

[GrantRobertson]

I would keep the engine stock.

 

[eDJ_]

I'd go with that 7.3 V8 Diesel if it is still there. It will go fast.   (I'd leave that V 10 or any of those Triton's alone)

The 7.3 is a 444 CID engine with a great track record.  But ford went with a 6.0 365 CID which has never
measured up to the 7.3 which is no longer available in Fords. 

The 7.3 should have the power to tow.   Later engines like the 6.0 may be a disappointment for towing.

I'm sure that there are others here with more Diesel experience than I have with regards to Pickup trucks
and Vans.   Most of what I know about it I've learned from a friend who runs a Diesel repair shop.

 

[masterplumber]

I ran a 7.3 Pickup for well over 200,000 miles with no engine problems other than the glow plugs. And almost all of those miles were loaded to max GVWR or above and probably half involved towing something or another. I'm not sure what year Ford switched from the E4OD trans - I think it was right around 1999, but if it has one and hasn't been rebuilt - plan on it. They can be made bulletproof however with a little work. If it feels like it's slipping while shifting, and the shift points feel odd, but otherwise performs well, try just replacing the torque converter - a common issue. There are Billet ones available that will be up to anything you throw at it.
Now the bad news, and this would apply whether it's diesel or gas. When I traded the truck in the rest of the mechanicals and electronics were falling apart. I'd rebuilt the front end once, and it needed it again. I'd replaced numerous sensors and even the entire computer module. The seats were shot and even though there were no rips, they had no support left. All this is probably pretty common with any brand once you get those kind of miles on them, and in fact my current Ram truck has had some of those same problems already and it's just about to hit 65,000 miles. I think if I was going to build a shuttle bus conversion, I would look for a bus built on a medium duty chassis like an International, F750 Ford, or Chevy Top Kick. They are out there, but unfortunately most are probably way to long for your needs - most are the size of a full length bus. Between your 2 current choices, I would definitely go with the 7.3 E350, if all other things are relatively equal.

 

[Ballenxj]

The big drawback is the cost of parts. I have a 7.3 with electronic injection in a 97 Ford pickup that is totaled for the price of parts even though the engine is far from being worn out. It has a little under 300,000 miles on it and needs a full set of injectors and a high pressure pump. Parts cost around 2500.00 for rebuilts with exchange. I also have a rusted out 1990 Ford with a good strong 7.3 that uses mechanical injection that will be swapped in as soon as I get the time. I can get a full set of mechanically controlled injectors  for less than 200 bucks when the need arises and an injector pump is in the neighborhood of 500. Plus, no computer or expensive relays and such to replace ever.

Good information here, most of which I was unaware of. Had I know all this before, I would have been a much wiser shopper.

 

[highdesertranger]

450+ Views and only 3 people voted, com'on it's not like we are voting for the prez or anything. highdesertranger

 

[GrantRobertson]

450+ Views and only 3 people voted, com'on it's not like we are voting for the prez or anything. highdesertranger

Well, HDR, I only threw on the poll as an afterthought. I think everyone just wants to see what you and Bob have to say. Heck, I made the poll and I didn't even vote. So much for democracy, huh?

But I have decided to go with a modern, computerized diesel engine. I know repairs will be more expensive but I fully expect environmental issues to make a lotta sh*t hit a lotta fans in 15-20 years. When that happens, I want to be able to hook up a woodgas generator without drastically modifying the engine.

 

[Optimistic Paranoid]

But I have decided to go with a modern, computerized diesel engine.

Let me share a thought with you.  I've had two different GM cars where the ABS system went out, and when we investigated the problem, found corrosion on the contacts of a multi wire plug on the firewall in the engine compartment.

Sternwake did a post on magic electrical juice:

https://vanlivingforum.com/Thread-Dang-near-magical-electrical-contact-juice

I've pretty much decided that using this stuff on all the contacts every other year or so would be a terrific form of preventative maintenance on the newer, high tech vehicles.

Regards
John

 

[GrantRobertson]

Let me share a thought with you.  I've had two different GM cars where the ABS system went out, and when we investigated the problem, found corrosion on the contacts of a multi wire plug on the firewall in the engine compartment.

Sternwake did a post on magic electrical juice:

https://vanlivingforum.com/Thread-Dang-near-magical-electrical-contact-juice

I've pretty much decided that using this stuff on all the contacts every other year or so would be a terrific form of preventative maintenance on the newer, high tech vehicles.

Regards
John

In old motorcycle land, where I used to live, if you didn't have dielectric grease on EVERY electrical connection, people would pretty much just point and laugh. In network land, where I used to work, bad connections caused about 90% of the problems that weren't caused by either stupid users or stupid coworkers. So I will give this stuff a try.

 

[akrvbob]

One thing HDR and I would agree on totally is NOT to buy a modern computerized diesel.

I could easily persuaded to take an older 7.3 Ford or Cummins if everything was right.

I just don't know anything about Chevy diesels except that HDR says the 6.2 is good and lots of them because of the military. On that alone I would at least consider one.
Bob

 

[GrantRobertson]

One thing HDR and I would agree on totally is NOT to buy a modern computerized diesel.

Yeah, am going back and forth on this one, Bob. On the one hand, computerized diesels can easily run wood gas or biodiesel. Older ones require engine modifications to allow adjustment of injector pressure or to just turn them off at the right time. On the other hand, older ones are easier and cheaper to work on. But then again, older ones both have more miles on them and were made to looser tolerances with older materials, so they are much more likely to need to be worked on. And, of course, older ones are cheaper to get in the first place, with price differences sometimes enough to cover the cost of a remanufactured engine.

Wait... I think I just talked myself into getting an older one. I gotta stop listening when I am talking to myself. [emoji6]

So, what are the last year's Ford, Chevy, and GMC put non-computerized diesel engines into van chassis?