gas vs diesel
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Mike_Lipke
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Better in what way?
IslandTractor
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It's not a question of one being better than the other but rather that each has specific strengths, weaknesses, advantages, and disadvantages for particular tasks. If you can better define what you want to do with said engine I am sure you'd get a better answer to your question.
RalphVa
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Gasoline is far more dangerous to handle than diesel fuel.
Diesel engines use 50% less fuel than carbureted gasoline engines and 30-35% less than fuel-injected gasoline (almost no utility engines are fuel-injected gasoline though). The first figure is from our vehicle records back in the 70s and 80s when about half of us engineers had diesel engined vehicles. The second figure comes from the government publication on EPA fuel mileage. Diesels use less fuel because of fuel with more energy/gallon and because the high compression causes more cooling of the exhaust gases on compression release.
Diesel engines will start instantly (after the appropriate amount of glowing or preheating, usually 1-5 seconds now on modern diesels) compared to carbureted engines. I had one sit for 6 months, put the battery back it, glowed it, turned the key and vrooom.
Diesels have more torque: more tackoff "kick" or lugdown potential, less wear on clutches as you can take off almost at idle. The torque is almost like a second flywheel, to keep the engine from dying under heavy load. A diesel-engined Benz E320 will outrun a gasoline-engined one.
By the end of 2006, diesels running on fuel from the pump for cars and trucks will smell better, as it'll be "water white" (clear) and have less than 15 ppm sulfur. You can even run "green" fuel: fuel made from plant material (biodiesel).
Ralph
Diesel engines use 50% less fuel than carbureted gasoline engines and 30-35% less than fuel-injected gasoline (almost no utility engines are fuel-injected gasoline though). The first figure is from our vehicle records back in the 70s and 80s when about half of us engineers had diesel engined vehicles. The second figure comes from the government publication on EPA fuel mileage. Diesels use less fuel because of fuel with more energy/gallon and because the high compression causes more cooling of the exhaust gases on compression release.
Diesel engines will start instantly (after the appropriate amount of glowing or preheating, usually 1-5 seconds now on modern diesels) compared to carbureted engines. I had one sit for 6 months, put the battery back it, glowed it, turned the key and vrooom.
Diesels have more torque: more tackoff "kick" or lugdown potential, less wear on clutches as you can take off almost at idle. The torque is almost like a second flywheel, to keep the engine from dying under heavy load. A diesel-engined Benz E320 will outrun a gasoline-engined one.
By the end of 2006, diesels running on fuel from the pump for cars and trucks will smell better, as it'll be "water white" (clear) and have less than 15 ppm sulfur. You can even run "green" fuel: fuel made from plant material (biodiesel).
Ralph
Diesel fuel will burn throughout the entire combustion stroke. Slow and steady push. Gas is much more volitile, kind of like hitting a golf ball, the piston travels because it was "hit" by the combustion(ouch). The slow burn characteristic reduces wear because it doesnt hammer the bearings or side load pistons.
Diesel is also lubricating as compares to the "dry" solvent properties of gasoline. This also reduces wear in the cylinder. With proper maintenance, good fluid qualities, and low idle times, a diesel engine can easily outlast us. When the new ULSD goes nationwide next year, it will greatly reduce emissions, odor, and soot.
With direct injection, electronics, and turbocharging, todays diesels have the performance of a gasoline engine. My nod is for diesel in most cases, though for on road vehicles our choices are slim.
Diesel is also lubricating as compares to the "dry" solvent properties of gasoline. This also reduces wear in the cylinder. With proper maintenance, good fluid qualities, and low idle times, a diesel engine can easily outlast us. When the new ULSD goes nationwide next year, it will greatly reduce emissions, odor, and soot.
With direct injection, electronics, and turbocharging, todays diesels have the performance of a gasoline engine. My nod is for diesel in most cases, though for on road vehicles our choices are slim.
tjkadar
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In 2007, all on the road diesel will be ultra low sulfur. However, that fuel is causing a lot of problems for engine manufacturers and folks that rely on diesel motors. In 2002, there was as 7% to 8% price increase on trucks. It could be even more then that in 2007. In addition, the fuel will have at least 1% less energy then our current diesel and cost (Chevron estimates) 3 to 7 cents more per gallon. Currently, the price of ULSD is $4.35 a gallon when purchased in bulk.
ULSD will likely kill off diesel motors for cars and pick-up trucks. Many of the large fleet carriers are buying up motors now, instead of being faced with the 2007 engines. ULSD is not a panacea. It will come with poorer fuel economy, less hp, and increased costs.
Maybe after a few years of burning ULSD we'll be able to engineer our way back to where we were before, but it is going to be a long, ardous, expensive road.
ULSD will likely kill off diesel motors for cars and pick-up trucks. Many of the large fleet carriers are buying up motors now, instead of being faced with the 2007 engines. ULSD is not a panacea. It will come with poorer fuel economy, less hp, and increased costs.
Maybe after a few years of burning ULSD we'll be able to engineer our way back to where we were before, but it is going to be a long, ardous, expensive road.
Buckeye_Jim
Silver Member
My VW Jetta TDI has an amazing amount of zip while getting 50 MPG on the highway and better than 40 mpg around town.
It makes me wonder how our country's energy dependance on the middle East could disappear if more similiar vechicles were in use.
Jim
It makes me wonder how our country's energy dependance on the middle East could disappear if more similiar vechicles were in use.
Jim
thank u for your input. i have a rental store in pa we r looking at adding a diesel mech and my mech and i were talking about how hard it was diagnosing problems.is gas harder or is diesel, he is a car mech turned into an equipment mech with a mix of small hp gas and diesel more and more we r seeing smaller diesel engines and he kind of afraid of the diesel. he is a great mech i am trying to give him some conf in fixing diesel, i have all the faith in the world in him, but he doubt himself. that is his nature
linpat,
As far as servicability, you could be all over the board there.. Up untill a few years ago, most diesel trucks were using very basic diesel designs. Now, we're seeing allot more technology applied to them. With proper training and care about their work, the same guy can work on diesel and gas. Diesel parts are generally heavier and require more effort to move when repairing(ie: aluminum heads vs cast iron). Gas and diesel drivability are closer than ever, you just need to understand the system you're working on.
As for the fuel economy, BuckeyeJim, arent you running ULSD? All the reports I have heard show to be positive,it may be more expensive but I believe that explains why the current diesel cost has not returned to pre-Katrina rates. We're used to the price, their making a profit now, when it changes, they wont have to adjust the price again.... Just my thoughts, time will tell... I see the ULSD as being a very positive development...
As far as servicability, you could be all over the board there.. Up untill a few years ago, most diesel trucks were using very basic diesel designs. Now, we're seeing allot more technology applied to them. With proper training and care about their work, the same guy can work on diesel and gas. Diesel parts are generally heavier and require more effort to move when repairing(ie: aluminum heads vs cast iron). Gas and diesel drivability are closer than ever, you just need to understand the system you're working on.
As for the fuel economy, BuckeyeJim, arent you running ULSD? All the reports I have heard show to be positive,it may be more expensive but I believe that explains why the current diesel cost has not returned to pre-Katrina rates. We're used to the price, their making a profit now, when it changes, they wont have to adjust the price again.... Just my thoughts, time will tell... I see the ULSD as being a very positive development...
Buckeye_Jim
Silver Member
Linpat,
I am probably running low sulfur in deisel in the Jetta and my Dodge 2500 truck. I had heard that California has a winter formula and one for the rest of the year. Use the dyed deisel in the tractor and need to look into an anti-gel additive for it.
Also I would use biodeisel if it was available locally for the Jetta.
Jim
I am probably running low sulfur in deisel in the Jetta and my Dodge 2500 truck. I had heard that California has a winter formula and one for the rest of the year. Use the dyed deisel in the tractor and need to look into an anti-gel additive for it.
Also I would use biodeisel if it was available locally for the Jetta.
Jim
Jim,
The reason I asked is that to my understanding, all of California is already using the "new '07 ULSD" the rest of us will start getting next year. Just curious if you were experiencing any of these phantom concerns.......
Greg
The reason I asked is that to my understanding, all of California is already using the "new '07 ULSD" the rest of us will start getting next year. Just curious if you were experiencing any of these phantom concerns.......
Greg
slowrev
Elite Member
Diesel will give you more power and will burn less fuel. However with the cost of diesel fuel now that seems to be about a wash.
diesels will last longer ? But will cost more to repair.
In cold weather starting Gas engines do far better than diesel.
With all that said, for Tractors go with diesel /forums/images/graemlins/smile.gif
Ben
diesels will last longer ? But will cost more to repair.
In cold weather starting Gas engines do far better than diesel.
With all that said, for Tractors go with diesel /forums/images/graemlins/smile.gif
Ben
dieselsmith
Bronze Member
I know it as a heck of alot colder ride to work in my 2500 Dodge diesel than it is in my wifes car! Plugging them in helps too! A diesel really shines in pulling power. The fastest truck in the world is a Cummins powered Dodge Dakota built by Gale Banks. These are just a few examples.
slowrev
Elite Member
A diesel really shines in pulling power.
//
Yep, that is why I said for a tractor get a diesel /forums/images/graemlins/smile.gif
Goes for working trucks too, But for a truck just mostly to ride in I think I would get a gasser.
Ben
//
Yep, that is why I said for a tractor get a diesel /forums/images/graemlins/smile.gif
Goes for working trucks too, But for a truck just mostly to ride in I think I would get a gasser.
Ben
Bluecheck546
Silver Member
"diesels will last longer ? But will cost more to repair." I beg to differ. Average lifetime of a diesel engine is 450000 miles versus 150000 of a gasser. So naturally per mile driven it would cost less to repair a diesel. /forums/images/graemlins/grin.gif
slowrev
Elite Member
verage lifetime of a diesel engine is 450000 miles versus 150000 of a gasser. So naturally per mile driven it would cost less to repair a diesel.
//
Yes it will likely cost less on a per mile basis. But a bigger hit on the ol pocketbook when it does need repair.
I have friends getting rid of diesel pickups because of high repair costs. It seems that repairs are needed before 450,000 miles.
Ben
//
Yes it will likely cost less on a per mile basis. But a bigger hit on the ol pocketbook when it does need repair.
I have friends getting rid of diesel pickups because of high repair costs. It seems that repairs are needed before 450,000 miles.
Ben
At this point you are mostly correct(IMO)...
As far as a 3/4ton diesel truck for a grocery getter, your right... The fuel economy doesnt cancel out the maintenance cost.
If your talking a VW diesel, made for commuting(45mpg diesel vs 25mpg for gas), I disagree. After the ULSD fuel becomes more available, you should start seeing more choices in diesel vehicles. This should dramaticly change the publics perception of diesel vehicles. The odor will be ruduced, sooting and carbon will also be ruduced. New common rail engines are already quieter. As long as the filling stations provide a clean pumping area, I see the possibility of allot more diesel acceptance in the U.S. over the next couple of years.
So, back to your statement of diesel benifit, unless you're talking about a VW I'll concede that point. But if I have the need for an Excursion it will most definitly be a diesel. 20mpg vs 10mp for V-10 is a definite selling point for me. I would rather pay more for service than need to stop for gas every 300mi.(750mi for a diesel Excursion)..Another thought, if you tow or do any work with your truck, a gas engines life will be greatly ruduced when compared to a diesel doing the same work.
As far as a 3/4ton diesel truck for a grocery getter, your right... The fuel economy doesnt cancel out the maintenance cost.
If your talking a VW diesel, made for commuting(45mpg diesel vs 25mpg for gas), I disagree. After the ULSD fuel becomes more available, you should start seeing more choices in diesel vehicles. This should dramaticly change the publics perception of diesel vehicles. The odor will be ruduced, sooting and carbon will also be ruduced. New common rail engines are already quieter. As long as the filling stations provide a clean pumping area, I see the possibility of allot more diesel acceptance in the U.S. over the next couple of years.
So, back to your statement of diesel benifit, unless you're talking about a VW I'll concede that point. But if I have the need for an Excursion it will most definitly be a diesel. 20mpg vs 10mp for V-10 is a definite selling point for me. I would rather pay more for service than need to stop for gas every 300mi.(750mi for a diesel Excursion)..Another thought, if you tow or do any work with your truck, a gas engines life will be greatly ruduced when compared to a diesel doing the same work.
slowrev
Elite Member
HGM,
I agree with you on the passenger cars with diesels. We need more of them /forums/images/graemlins/smile.gif
Ben
I agree with you on the passenger cars with diesels. We need more of them /forums/images/graemlins/smile.gif
Ben
Gumby6
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At the risk of straying off subject...
I have a 2001 PSD Excursion. Only reason I purchased this vehicle was for pulling power with the PSD and longevity (didn't want to have to buy again in a few years).
I have been very satisfied with the power plant. But longevity, in general, is becoming a problem. Leave it to Detroit to figure out that tweaking these newer ECM regulated engines, yields more horsepower, more WOW, and quicker replacement.
Case in point, the new PSD is smaller with more horsepower, more aluminium is in use also. With the stresses these engines are placed under today...
Aluminium <> Cast Iron
and nothing good can come of this, nothing, nothing... /forums/images/graemlins/frown.gif
Haven't heard of a tractor diesel with aluminium heads or block yet..and that's a good thing. /forums/images/graemlins/smile.gif
JMHO
I have a 2001 PSD Excursion. Only reason I purchased this vehicle was for pulling power with the PSD and longevity (didn't want to have to buy again in a few years).
I have been very satisfied with the power plant. But longevity, in general, is becoming a problem. Leave it to Detroit to figure out that tweaking these newer ECM regulated engines, yields more horsepower, more WOW, and quicker replacement.
Case in point, the new PSD is smaller with more horsepower, more aluminium is in use also. With the stresses these engines are placed under today...
Aluminium <> Cast Iron
and nothing good can come of this, nothing, nothing... /forums/images/graemlins/frown.gif
Haven't heard of a tractor diesel with aluminium heads or block yet..and that's a good thing. /forums/images/graemlins/smile.gif
JMHO
