Diesels For Duty Vehicles

[x635 4,066]

I'm curious to find out what everyone thinks on this topic.

I'm reffering to Duty Vehicles such as Fire Shift Commander or Supervisors Cars, EMS lycars and Police Cars that run nonstopand have gasoline engines.

Do you feel a gas or diesel engine is more suitable for the above purposes?

Also, it seems to me that there's no more options for a diesel SUV on the market. Last I heard, Ford was developing a Diesel for the '07 Expedition XL, but I havn't hear mujch about that. Seems Ford has scaled back a lot in their development.

Do you think that diesel engines last longer, or is that just a myth? Is the transfer or use of gasoline vehicles shorten the vehicles lifespan?

If Toyota was to develop a full-size SUV with a diesel engine, would your department consider that?

How important is it to your fleet to have diesels vs. gas?

Lastly, am I missing anything- any diesel SUV coming out?

Edited March 13, 2007 by x635

[IzzyEng4 427]

Me personally, unless the duty vehicle is going to also be used for pulling trailers and other equipment then year I think it would be ok. But if it is for normal wear and tear and mainly used for driving around then no.

[Guest]

Well, its my understanding that Ford is having alot of issues right now - which would explain their lack of enthusasim for new product models. They probably want to stay with whats tride and true to get sales up.

Per the topic, to be honest, i havent seen any disel flycars of any flavor. All of the flycars ive seen ahve been gasoline Hummers, Tahoes, Explorers, Expidtitons, Sububrbans, etc. I'm not an engine man, but i tend to think a diseal engine is a bit more ruged and built to last - i mean they say it doesnt even get broken in until 100,000 miles. It seems like an interesting option.

I think for the most part, the above mentioned cars have offered decent platforms for flycar/supervior cars. Of the above, im not aware of a disel varrient..maybe this is the reason?

[mstrang1 213]

Stamford Fire & Rescue has a Ford Excursion with a diesel motor. It's a lot louder than the older gas vehicle (obviously) but mechanically as far as I know runs very well. It is assigned to Car 4, the on-duty Deputy.

[Guest]

Jeep has a Continuous Rail Diesel available currently in the Liberty and soon to be added to the Grand Cherokee. The motor is a Mercedes motor and I would buy it, if I was looking for a truck. In europe almost every car is a diesel or a 1 liter engine gas engine. Our crash standards and desire for performance deny these engines access to the American market, besides the morons at the EPA and CARB. Ive seen a 1.5 liter BMW for crying out loud, now thats a small engine in a heavy car, but that wasnt in this country. At work every Battalion car is a Diesel Excursion. They replaced the Suburbans when Chevy decided to no longer produce the diesel variant. Diesels work completely different than gasoline engines. They last longer because of many reasons, but the main one usually being the lack of need for high rpms from the motor to produce power. They get better fuel mileage due to the fact that the principle behind the motor is the compression of air and fuel to create the power with just heat no spark, add a turbo to that and voila more horsepower without the usual loss of mileage like with a gas engine. Its more complicated than this of course, but thats the gist of it.

Hell a diesel pickup with a new computer and an exhaust adds 130+ hp and over 200lbs of torque, thats power!!!!!

[mfc2257 464]

If you do the math with regard to initial cost (which is high... but) increased fuel economy, lack of need for maintenence, and life expectancy..... A diesel is the ONLY option for a vehicle that is expected to be used for more than 5 years.

Let us not forget too, that the high torque of a diesel motor allows for transmissions to be shifting less often in stop and go traffic because they do not require nearly the amount of downshifts to maintain road speed in a congested enviorment.

Finally the resale value of a diesel either at auction or on the open market is much higher than a gasoline powered rig.

Downfalls: High initial cost, currently (although not historically) diesel is more expensive

Benefits: MUCH better fuel economy, less wear on the tranny, less maintenence costs, better low end power (which is what most duty vehicles need) better resale value.

Edited March 14, 2007 by mfc2257

[CFD320 35]

Diesel fuel (same as #2 oil)

Generally, diesel engines make much more low end torque than their gasoline counterparts especially at low RPM because of the high compression ratios necessary to ignite the fuel 17:1 (all firemen should know that gas is much more volatile). It is true that a diesel engine is more efficient overall than gas BUT it takes 25% more crude oil to produce a finished gallon of diesel than it does to make a gallon of gas. It does not take a rocket scientist to figure out that diesel will generally always be more expensive than gas. Diesel engines have trouble starting in very cold weather without a block heater as the fuel has a tendency to gel. Also because of the ignition system that includes glow plugs proper starting and warm-up of the engine is highly recommended. When seconds count waiting for glow plugs and engine temp to rise is not a good thing

Gas engines generally make more horsepower than equivalent size diesels, they rev faster and have higher RPM peaks than do diesels. That combination makes for better 0-60mph times and and more driving "speed". Gas engines also have an advantage in short term maintinence required (long term diesel has a huge advantage), they necessitate less crank case oil, don't require much care until 80k or so.

My answer to this question is Gas.....

Edited March 14, 2007 by CFD320

[Guest CRASH]

Jeep has a Continuous Rail Diesel available currently in the Liberty and soon to be added to the Grand Cherokee.  The motor is a Mercedes motor and I would buy it, if I was looking for a truck.  In europe almost every car is a diesel or a 1 liter engine gas engine.  Our crash standards and desire for performance deny these engines access to the American market, besides the morons at the EPA and CARB.  Ive seen a 1.5 liter BMW for crying out loud, now thats a small engine in a heavy car, but that wasnt in this country.  At work every Battalion car is a Diesel Excursion.  They replaced the Suburbans when Chevy decided to no longer produce the diesel variant.  Diesels work completely different than gasoline engines.  They last longer because of many reasons, but the main one usually being the lack of need for high rpms from the motor to produce power.  They get better fuel mileage due to the fact that the principle behind the motor is the compression of air and fuel to create the power with just heat no spark, add a turbo to that and voila more horsepower without the usual loss of mileage like with a gas engine.  Its more complicated than this of course, but thats the gist of it.

Hell a diesel pickup with a new computer and an exhaust adds 130+ hp and over 200lbs of torque, thats power!!!!!

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i know as per the chrysler/mercedes diesel engines UPS is using them in their newer fleet and they stink no torque no power nothing the trucks they are used on are actually mostly the smaller p700's in the fleet which dont go out as heavy as the larger p1000 or p1200 delivery vehicles i personally have driven them and they just are not adequate in my oppinion ...

[trauma74 111]

I am totally in favor of having any continuous duty vehicle with a diesel engine. The problem is that our choices are limited. Chevy stopped making the Suburban with a diesel, Ford stopped making the Excursion plus they never offered the Expedition or the Explorer with a diesel motor option, Dodge does not make an SUV with a diesel, Ford also now stopped making the E-Series in a diesel.

Diesel fuel by nature is an oily type of fuel. With that being said, that is one of the reasons why diesel engines last longer. The more lubrication you have the less friction you have, less friction results in less wear and tear on the engine and better fuel economy.

There are some negatives when it comes to purchasing a vehicle with a diesel. Cost is the main thing. On many vehicles you are talking about a $3K-$5K difference in the price. In the long run I think spending the extra money up front is worth it.

Diesel motors stand up better to long periods of idling. As many of you already know, idling and heavy duty usage with a gasoline engine will result in the engine not lasting very long.

As stated in one of the posts above, the majority of vehicles in Europe are diesels. The major car companies need to get on the ball with offering more vehicles with diesel engines.

If any one you have watched "Future Vehicles" on the Discovery channel you saw many new concept cars being made with diesel engines. In one such case, there was a Formula One style race car that runs on diesel. This race car averaged 150mph in a race while getting 113mpg!!!!!!!! If a car like that can get that kind of performance, the future of diesels looks brighter every day.

In addition to performance, you have a few alternative types of diesel fuel to use in a diesel engine. You have the new low sulfer fuel and a few different types of bio-diesel. You can make bio-diesel in your own garage. The equipment does not seem very expensive, but it appears to be time consuming. Many restaurants discard their used cooking oil. They have to pay to get this oil removed. Many of them have no problem letting people take their used oil. It saves them money.

Bio-Diesel can be made from many different types of crops. Bio-Diesel can be mass produced. This can help reduce our dependency on oil from terrorist countries. There are ways to make gasoline like fuels from other sources, but the process is more time consuming and more expensive.

It would be nice to see the Tahoe & Suburban offered with the Duramax engine paired up with a nice Allison transmission!

[Arrowxt 8]

The worst thing to do with a diesel engine is to idle it more than 3 minutes, diesel is no longer just 2 oil and the engine is only as good as its crank as the compression ignition beats the bottom end to death.

But with what they have done with them in the last few years , they are a great investment.

Thank the computer for that.

Arrow

[Guest]

I'm a big fan of diesel engines. I have a 2005 Jeep Liberty Diesel and I love it. It has plenty of torque and power and gets good fule mileage. It would make sense to make these staff cars. Unfortunately Jeep is not making the diesel Liberty any more, and is going to put a cleaner diesel in the grand cherokee. It will be a totaly different engine. I read when the liberty platform is revamped there will be a new diesel engine offered for it. I was lucky enough to get mine as a leftover, and got a great deal on it. My piciup truck is a 1979 chevy I converted it into a diesel. I installed a Cummins 4BTA four cylinder turbo diesel. It runs great and gets good mileage for a truck that size. for street driving the torque is decent and power is good. When it is off road and in low range is where the power and torque are really notable. I'm really happy with both trucks. If the widespread usage of biodiesel becomes commonplace. Diesels will become a popular option for vehicles of all sizes. A biodiesel mix of 80%diesel fule and 20%biodiesel (aka B20) has been found to be a good mix for engine wear, emmissions, and fule gelling. I really hope it takes off.

[Guest partyrock]

It seems just about everyone has stated dropping deisel's from the product line the past year or two just as their popularity was starting to grow. I'm assuming this from the new emissions regulations diesels have to meet. Does anyone have some info on who has new engines comming out in the near future or with the next modle redesign?

[mfc2257 464]

Diesel fuel (same as #2 oil)

Generally, diesel engines make much more low end torque than their gasoline counterparts especially at low RPM because of the high compression ratios necessary to ignite the fuel 17:1 (all firemen should know that gas is much more volatile).  It is true that a diesel engine is more efficient overall than gas BUT it takes 25% more crude oil to produce a finished gallon of diesel than it does to make a gallon of gas.  It does not take a rocket scientist to figure out that diesel will generally always be more expensive than gas.  Diesel engines have trouble starting in very cold weather without a block heater as the fuel has a tendency to gel.  Also because of the ignition system that includes glow plugs proper starting and warm-up of the engine is highly recommended.  When seconds count waiting for glow plugs and engine temp to rise is not a good thing

Gas engines generally make more horsepower than equivalent size diesels, they rev faster and have higher RPM peaks than do diesels.  That combination makes for better 0-60mph times and and more driving "speed".  Gas engines also have an advantage in short term maintinence required (long term diesel has a huge advantage), they necessitate less crank case oil, don't require much care until 80k or so.

My answer to this question is Gas.....

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Don't want to start an argument here, but where are you getting your information regarding the amount of crude needed make a gallon of diesel vs. a gallon of gasoline. By nature diesel is a less refined product than gasoline and thus logic would argue that it takes less crude to make a gallon of diesel vs. a gallon of gasoline. Historically, diesel has been less expensive than gasoline. I would argue, that the reason behind the diesel price premium over the past 18-24 months is more a product of demand. Since the turn of the century (2000 that is) look at the number of Cummins, Duramax, and Powerstroke diesels that have been placed into service where gasoline fired V-8's had been used historically. I'd argue that more than half of all 3/4 ton and heavier service pickups sold today come with diesel power. 15 years ago, no one was buying underpowered, smoke belching diesels.... ESPECIALLY people buying pickups for personal use. Today, everyone's got a shiny new diesel fired rig with leather interior and satallite radio. There has been a greater demand for government use as well with the majority of vans being powered by diesels as well. The delivery industry has followed as well with just about every brand name carrier using diesel power for local delivery. SO how does this all translate into price, there aren't enough diesel refineries to keep up with the increased demand over the past 15 years. When International turbocharged the Navistar (Powerstroke), Chevy started using Izuzu's Duramax, and Cummins put at 24valve head on their trusty 5.9L, diesels started making equal horsepower and GOBS more torque than gas fired motors. Too much demand for diesel, not enough supply = higher costs.

Not seeing the logic on where a diesel has more short term maintenance concerns than a gas fired rig.

Compare diesel horsepower and torque ratings to gas fired motors over the past 7-8 years and I think you'll find that most of the time the diesel's on par or has an advantage.

[Guest]

Just some info on diesel fuel i dug up:

Diesel fuel has a higher energy density than gasoline. On average, 1 gallon (3.8 L) of diesel fuel contains approximately 155x106 joules (147,000 BTU), while 1 gallon of gasoline contains 132x106 joules (125,000 BTU).

Diesel fuel becomes diesel when crude oil is heated to between 250 - 350 c while gasoline becomes gasoline at when it rises through to the top of the distillation colum @ roughly 20c.

Make a long story short - Diesel fuel is closer to crude/petroleum than gasoline is. Likewise, Diesel fuel has a higher concentration of carbon atoms, which means gallon for gallon it has more potential energy than gas. Because a diesel engine uses less diesel to achieve the same power output as a gas engine its said to be fuel efficient. Only thing is, diesel isn't nearly as "clean" as gas...your just spreading the emissions out over a longer distance/period. As far as low-sulfur diesel, i bet the price per gallon is astronomical.

I couldn't find anything about how much of what fuels a gallon of crude makes, but i did find that 40% of refined crude distills into gasoline and often different grades of oil distilled off at temperatures close to that of gas are chemically treated to become gasoline.

Edited March 18, 2007 by 66Alpha1

[Guest]

Diesel is more closer to crude in the cracking process the next is kerosine, than gasoline. Its layered in the cracking tank. The neet thing about diesels is the potential for an alternative fule like biodiesel. There is a city in California that collects fourty tons of used cooking oil per month and makes their own fule. They use it in all diesel powered vehicals, and keeps it out of the landfill. Farmers can grow soy beans, peanuts and more to make it. It is biodigrageable, and renewable. I heard something on the news the other day that the price of BEER may go up because more farmers are growing corn to make ethanol to blend into gasoline than growing barley! Biodiesel can be made from many different crops as well as anminal fats.

[Guest]

Diesel is more closer to crude in the cracking process the next is kerosine, than gasoline. Its layered in the cracking tank. The neet thing about diesels is the potential for an alternative fule like biodiesel. There is a city in California that collects fourty tons of used cooking oil per month and makes their own fule. They use it in all diesel powered vehicals, and keeps it out of the landfill.  Farmers can grow soy beans, peanuts and more  to make it. It is biodigrageable, and renewable. I heard something on the news the other day that the price of BEER may go up because more farmers are growing corn to make ethanol to blend into gasoline than growing barley! Biodiesel can be made from many different crops as well as anminal fats.

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Heard the same story. I also saw a special on biodiesel on the discovery channel a few months ago. Apparently the emission smells like french fries

[Guest]

Heard the same story. I also saw a special on biodiesel on the discovery channel a few months ago. Apparently the emission smells like french fries 

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Yes it does. I thought about making my own and even talked to a local resturaunt about collecting their old oil. It requieres some special equipment and mixing of methanol and lye. I live in the middle of Norwalk. I dont want to build a biodiesel plant in my back shed. My neighbors already look at me funny. LOL

[Guest]

Yes it does. I thought about making my own and even talked to a local resturaunt about collecting their old oil. It requieres some special equipment and mixing of methanol and lye. I live in the middle of Norwalk. I dont want to build a biodiesel plant in my back shed. My neighbors already look at me funny.  LOL

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Ha, the guy they featured had a shed with a few vats that helped to filter and process everything. I think mythbusters also did a feature on it and actually took a desiel and took straight used cooking oil, put it through a simple paper filter and ran the car straight on that.

[Guest partyrock]

You can run straight recovered cooking oil, but it gels in cold weather and requires a parallel diesel system to start and operate the car until the oil is up to temp. Home made Biodiesel is processed cooking oil. Once you process the cooking oil it is almost interchangable with diesel.

[Guest bibbles10504]

Yea, I've seen it done, it worked pretty well

[Guest]

Yea, I've seen it done, it worked pretty well

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Its pretty cool, when Dr. Rudoph Diesel invented the engine over 100 years ago it was intended to run on boidiesel, when he displayed the engine it was running on peanut oil. Back then crude oil was cheap and plentyful and biodiesel wasn't used, we are actually running on fule never intended for our engines.