buickanddeere
Super Member
the order of generally avalible fuels in order of clean burning to dirty is hydrogen, natural gas, propane, gasoline , kerosene , #1,2,3,4,5 and 6 fuel oil. Hence all those LP forklifts instead of diesel forklifts .
Are Automakers This Stupid?
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Snobdds
Elite Member
Those are in a laboratory setting with ideal conditions and no pressure changes.
In an engine with varying compression ratios and high pressure fueling...all that goes out the window. The difference between port and direct injection changes the carbon output dramatically with the same underlying fuel source.
Technology gave us direct injection and technology will need to clean up the byproduct of direct injection.
buickanddeere
Super Member
Direct injection provides the lowest emissions and highest fuel efficiency with gasoline vs port injection or a carburator .
Snobdds
Elite Member
That is not true in any way. Period.
Mercedes is putting particulate filters on their direct injected gas motors because it's producing so many particulates. In order for direct injection to work, the combustion chamber must be pre-charged and that pre-charge goes right out the exhaust manifold to be partially burned in the cats.
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PJ The Kid
Bronze Member
I did a study in college, and I see it somewhat pertinent to the subject. We took a 5 gas analyzer and worked in partnership with a local trash fleet. The fleet analyst was of the idea that he could install propane injection systems and increase fuel efficiency and lower emissions. With the vehicle on a dyno we tried running it as a straight turbo diesel with the propane system turned off to gain a base line reading (don't ask me the numbers as it was about 5 concussions and 6 years ago) then we turned on the propane system and tuned the truck accordingly. The system was not standalone propane but set up as a power adder, We found that fuel efficiency on the dyno empty helo minimal gains, but particulate emissions and Co. emissions were reduced by a fair amount. On the other hand nOX emissions were substantially higher staying true to what we were taught about reducing emissions. When cO, particulate, and fuel use decrease, usually nOX increases.
Now loaded on the road was a somewhat different story for fuel mileage, we saw an average increase in milage when loaded and driving in the real word due to the engine having more power available. IE, not holding it to the floor for as long to attain speed with a load, or not having to use as much fuel to maintain speed on an incline.
This brings me to my point, there is always a happy medium between power, efficiency, and pollution. When you add to one, you take away from another, not including reliability which changes with all the above.
Now loaded on the road was a somewhat different story for fuel mileage, we saw an average increase in milage when loaded and driving in the real word due to the engine having more power available. IE, not holding it to the floor for as long to attain speed with a load, or not having to use as much fuel to maintain speed on an incline.
This brings me to my point, there is always a happy medium between power, efficiency, and pollution. When you add to one, you take away from another, not including reliability which changes with all the above.
PJ The Kid
Bronze Member
Also, a problem with direct injection is carbon build-up in the valves and intake ports. in a port injected engine, the fuel cleans the sealing face of the valves and the end of the intake ports. The ports and valves are dirty due to pcv being vented into the intake system as per EPA regulations. That is why may automakers are selling services such as walnut shell blasting the inductions system at certain mileage intervals, Also this carbon buildup decreases efficiency as it creates restriction and air turbulence in the induction system causing more un burnt fuel to exit thru the exhaust as particulate matter and cO, and C.
Seems there is a lot of "stuff" going down the tailpipe, in "modern" gas engine designs.
First, it was the Sx oil that had to change, to protect the cats. My first question was "why is so much oil going down the tailpipe?". I had even a life-long fanboy of a particular brand laughing when I said that my theory was they had actually put 2 stroke truck motors into production, and just not told anybody. A modern 2 stroke probably would use less oil than what those engines were going through.
The big players always win. Manufacturers don't have an issue with complex expensive repairs, so long as they can be pushed past warranty. Many people won't pay more that 4 or 5 months worth of new-car payments to fix an older car, so the scenarios discussed tend to drive new car sales. Govts reap more taxes under all conditions.
Up until, people just stop driving. I know a few people in my age bracket who have given up for economic reasons. Young people, crammed into cities, with massive expenses just for parking, often don't even bother getting a license. So, like most things, there is an end-limit to what people will/can put up with.
Then there is DI. Not all designs are terrible, but I know I'd be furious about laying out big $ for a "modern" engine, and being stuck with 1960's era 2-stroke levels of maintenance. That's probably not being fair to 60's 2-strokes....
The other thing I find striking is that at the same time as DI engines were ramping up, tailpipe emission testing stopped, at least here. The program continues, but instead we now rely solely on on-board computer reporting. Anyone who has studied science at all understands the value of direct observation. We are supposed to be cleaning up the environment (allegedly), yet we have moved away from the dyno based tail-pipe sniffing that VW (and others) would not have been able to beat.
Some of the engineering going on here has nothing to do with mechanical, electrical, or chemical systems, and definitely not air quality. Unfortunately, most of the population today does not know enough about science to make these distinctions.
Rgds, D.
First, it was the Sx oil that had to change, to protect the cats. My first question was "why is so much oil going down the tailpipe?". I had even a life-long fanboy of a particular brand laughing when I said that my theory was they had actually put 2 stroke truck motors into production, and just not told anybody. A modern 2 stroke probably would use less oil than what those engines were going through.
The big players always win. Manufacturers don't have an issue with complex expensive repairs, so long as they can be pushed past warranty. Many people won't pay more that 4 or 5 months worth of new-car payments to fix an older car, so the scenarios discussed tend to drive new car sales. Govts reap more taxes under all conditions.
Up until, people just stop driving. I know a few people in my age bracket who have given up for economic reasons. Young people, crammed into cities, with massive expenses just for parking, often don't even bother getting a license. So, like most things, there is an end-limit to what people will/can put up with.
Then there is DI. Not all designs are terrible, but I know I'd be furious about laying out big $ for a "modern" engine, and being stuck with 1960's era 2-stroke levels of maintenance. That's probably not being fair to 60's 2-strokes....
The other thing I find striking is that at the same time as DI engines were ramping up, tailpipe emission testing stopped, at least here. The program continues, but instead we now rely solely on on-board computer reporting. Anyone who has studied science at all understands the value of direct observation. We are supposed to be cleaning up the environment (allegedly), yet we have moved away from the dyno based tail-pipe sniffing that VW (and others) would not have been able to beat.
Some of the engineering going on here has nothing to do with mechanical, electrical, or chemical systems, and definitely not air quality. Unfortunately, most of the population today does not know enough about science to make these distinctions.
Rgds, D.
PJ The Kid
Bronze Member
Just a point on the engineering. When smog laws first started getting hot, remember what they added to the cars and light trucks? AIR PUMPS. Take air from past the intake at the filter, and pump it in a few inches up stream of the cat converters, The theory was the added air (O2) would cause the converters to ignite and burn hotter to burn the particulate and complete the conversion of the semi-burnt fuel. Very similar to the 6.4 powerstrokes adding fuel into the DPF system. There is a difference between the said reasoning and the real reasoning, Pumping fresh air into the converter allowed more un burnt O2 to exit the exhaust system for the analyzer to sniff.
Copperhead
Veteran Member
Well, Nikola is on target to release a electric semi truck that uses a NG turbine to drive a on board generator to replenish batteries. 2000 hp at the wheels. That will take care of some serious emissions from traditional semi trucks.
Nikola Motor gets $2.3B worth of preorders for 2, HP, electric semi-trailer truck | Computerworld
Nikola Motor gets $2.3B worth of preorders for 2, HP, electric semi-trailer truck | Computerworld
DieselBound
Elite Member
I'm still waiting for the flying cars we were all promised!:laughing:
While I'm sure that they can make one of these things work there's still the issue of whether it could be cost effective. Can't help but think that cargo capacity is going to be reduced: volumetric issue with NG.
At some point, as has been mentioned here, we need to step back and look at the big picture. How much emissions are being generated in the creation of these schemes, and how much more is going to be added for all the added maintenance?
Oh! And any time there's an accident you can expect that a hazmat team will be required.