Gasoline VS diesel - heavy equipment

[MossRoad]

If you're concerned about gas and carb issues, put a water bowl dirt separator thing on it like many old tractors had, and a couple of fuel filters. Check the bowl for dirt or water once in a while and drain it if needed. My old IH2500b had one of those bowls under the right fender tank that I once in a while saw a little dirt in, but never any water. Anyhow, if you're using it every couple weeks or so, you'll run plenty of gas through it. If you're only using it seasonally, put some stabil in the gas and start the machine up and run it for half an hour once a month or so.

 

[troverman]

Having operated both, it was easy to see why most heavy equipment went to diesel: fairly simple engines and fuel systems, very durable, lower fuel consumption, more torque...not a lot of extra cost to buy.

Fast forward to today, and that is changing. Used equipment is one thing, but new diesels all have to meet pretty stringent EPA requirements. Enter DEF, DPF, EGR, common-rail electronic injection, etc.

Because of emissions equipment, several things have happened to diesels:

1. They are much more expensive compared to gas, mainly because of the added required emissions controls.
2. They tend not to last as long as they used to. EGR cokes up valves; DPF regens can cause oil/fuel dilution depending on regen method
3. They are much harder and more expensive to work on. Everything is electronically controlled and there are a lot of sensors. Parts are expensive.
4. They don't get as good of fuel economy. While still good, regenerations burn diesel strictly for emissions cleaning.

Meanwhile, gas engines have gotten better. Longer lifespans, better fuel economy, more power.

Diesel still is the fuel economy and torque king, but it now comes at a higher cost in terms of up front price and maintenance.

Truly heavy equipment (Class 8 trucks, excavators, large tractors, etc, etc) all remains diesel. The advantages still outweigh the cons. But there has been surprising resurgence of gas engines in HD pickups and even medium-duty trucks, due to much lower operating costs.

In the end, I'm a fan of diesel...but a gas engine may get the job done at a lower price.

 

[buickanddeere]

Ah but Moss, You haven't mentioned anything about the time, aggravation and expense to get a carbureted engine running. Especially if you happen to get unlucky about the whole thing after letting it sit for a while. I have three gas engines on the yard. A generator which makes me go Grrrrr once in awhile, A quad which has never given troubles starting, but it's fuel injection. And a 47 IHC KB-1. It makes me go Grrrr once in awhile but I'm not changing it to a diesel!

The rest of our vehicles tractors mowers etc are all diesels because I hate fussing with carburetors.

Good point about planned usage and machine rentals.

Apparently you have not heard tell of Tier IV diesels , common rail fuel injection, glow plugs, variable wastegate turbos, urea injection, cat converters , particulate filters, regeneration, gelled fuel, cold weather starting and sensor failure.

 

[buickanddeere]

I was under the impression that you were buying new. If the price is right and the machine is in good shape buy it. It sounds like you have enough use for it that you'll be able to keep the gas fresh enough.

I come from the point of view that I'm tired of cleaning carburetors. Actually that's not totally true. What I'm tired of is trying to do a descent job of cleaning a carburetor and still keeping the price reasonable. If you have a really dirty carb it's at least a 2-3 hour job to clean it thoroughly.

Cheaper to purchase a new carb. Then again we use clean premium gasoline without ethanol and we do not have carburetor problems .

 

[oleman]

The diesel verses gas debate continues but recently major companies have moved from diesel to gas in the package delivery business. UPS in my area only runs gas engines. Also many municipal bus system are running what would be a diesel engine to LNG or propane, and possibly some on gasoline. School buses in some areas also run diesel to gas conversions. Doubt if there in reliability issue when a Cummins diesel is converted to gas.
My little 2013 Nissan Versa gaser has never had a mechanical issue since new.
Our old International 464 diesel utility always starts and runs fine but I expect the gas carbed engine would also be fine. One of the things about the old 70's diesel is that it takes no electricity to start and run, just fuel and air. NOT TRUE of the modern engine, it potentially has the same or more electrical issues than the FI gas engine.
Almost forgot, we also have a 71 series Detroit diesel built in 1955 that still powers a work boat.
Chain saw could be hydraulic so it can run off a hydraulic remote from the diesel utility, with the advantage of
almost noiseless operation. OR electric off an inverter for 115 VAC operation in the out-back

 

[pmsmechanic]

Apparently you have not heard tell of Tier IV diesels , common rail fuel injection, glow plugs, variable wastegate turbos, urea injection, cat converters , particulate filters, regeneration, gelled fuel, cold weather starting and sensor failure.

I've heard of them. For the most part I stay away. We'll leave those vehicles for people with money.

My wife does own a 2014 Jetta. We'll see how that one works long term. It's at 160,000 miles/200,000 km right now. We'll probably be it's only owners.

Many years ago I bought a 1990 Cummins for $2500. It had an indicated 395,000 km at the time. It's now sitting at 704,000 km. It's had a few problems but has been by far the most reliable vehicle I've ever owned.

 

[DieselBound]

I'm not thinking that people have full exposure to newer gasoline engines. They too have a significant array of sensors and emission controls. I know fleet mechanics that work on MANY things, and gasoline engines are not viewed by these folks as being any win over diesels.

My 17 year-old TDI VWs run just fine. Computers and EGR stuff included. I've cleaned intakes on two of three of these cars (third one came to be already cleaned); I don't expect to ever clean them again (variety of reasons, all which should easily eclipse the mileage that was on one car whose intake I cleaned at about 150k miles [performance was still great]).

My Kioti NX is Tier IV. Basically it's an additional DPF, which means a DPF and a couple of sensors (and software programming to monitor sensors and command regens). DPFs are rated for around 3k hours, after which they can be cleaned (once). 225 hours (a few regens) and ZERO engine problems.

ALL diesels with turbos use variable vane technologies: they have to because of the need for boost at lower RPMs (where diesels tend to run). Geez, my 17 year-old cars did/do! They also have catalytic converters, AND, injectors (huh?). They also start in cold weather Gelled fuel is the result of fuel and temperature, not the emission spec of an engine. Sensor failures? See my comment on gasoline engines above.

Diesel engines run on oil-based fuel. Bottom ends will always go a LOT longer than an equivalent gasoline engine's.

Between the three TDIs that my wife and I operate we've put on over 110k miles (in three years): lowest mileage is my car, with only about 162k; others are over 200k miles. Plenty of sensors on these cars. All have computers. All have EGR valves. ALL have "variable wastegate[sic] turbos." All have "injectors." The ONLY engine-related issue has been one failed MAF- yes, a "sensor" - $100- and a couple of glowplugs.

I've got a 1993 Ford F250 7.3L IDI with about 250k miles. It's my farm truck. While it always starts and runs (when I bought it with about 243k miles I had to replace all glowplugs, fuel return lines and GP controller), it's an absolute pig. I'll take direct injection and turbos any day: but my truck works well enough and I cannot justify buying something else.