Low sulfur diesel in older engine question

[3 Dog Nite]

Has anyone had any problems using the newer low sulpher deisel in their older vehicles? I know the tractor trailers have to add DEF (deisel exhaust fuel) additive in the new trucks. I'm thinking of purchasing a 1985 with a GM 6.2L engine. Are there any additives required to use the new fuel in an older vehicles. What problems have been caused by this phenomenom?

[r carl]

Maybe add 2 stroke oil in the fuel tank?

[cwf]

Originally Posted by 3 Dog Nite

Has anyone had any problems using the newer low sulpher deisel in their older vehicles? I know the tractor trailers have to add DEF (deisel exhaust fuel) additive in the new trucks. I'm thinking of purchasing a 1985 with a GM 6.2L engine. Are there any additives required to use the new fuel in an older vehicles. What problems have been caused by this phenomenom?

Get Diesel additive. There are several to chose from. The "new" diesel doesn't have the protection of the sulphur which the additive should help minimize injector and valve wear.

[RickDavis]

a subject of great debate. Some recommend various additives, some use transmission fluid or 2 cycle oil. I personally don't use anything unless it is below zero. I have used a biocide in my 1973 backhoe, but only because it sits a lot.
My 99 Dodge Cummins was built before ULSD and I have never used any additives. Perhaps if I had, my injection pump wouldn't have worn out at only 458,000 miles.
I am not convinced they are worth the money, but if I were to use one it would be a commercial product.

[Drathaar]

My Ford shop recommends using Stanadyne in my 7.3.

[handn]

Originally Posted by Drathaar

My Ford shop recommends using Stanadyne in my 7.3.

x2, I get about .5 to 1 mpg better fuel economy, better cold starts, quieter running and less smoke.
Ultra low sulphur fuel won't hurt your old diesel.

[Protagonist]

Originally Posted by 3 Dog Nite

Has anyone had any problems using the newer low sulpher deisel in their older vehicles? I know the tractor trailers have to add DEF (deisel exhaust fuel) additive in the new trucks. I'm thinking of purchasing a 1985 with a GM 6.2L engine. Are there any additives required to use the new fuel in an older vehicles. What problems have been caused by this phenomenom?

You are only required to use DEF in EPA Tier 3 or higher engines— usually featuring common-rail fuel injection— but you can use ultra-low sulfur diesel (ULSD, <15ppm sulfur) in any diesel engine.

Besides, you don't have a choice. All road-use diesel sold in the United States must be ULSD. Some off-road vehicles are still allowed to use Low Sulfur Diesel (LSD, <500ppm sulfur, no relation to the psychedelic drug) so be wary of refueling in places that see a lot of tractors, combine harvesters, etc.— they may have a LSD pump that will do very bad things to ULSD-required vehicles.

[choctawmel]

I lost 4mpg in my Dodge Cummins when the ULSD came out

[idroba]

Be real sure that the engine is working very well when you purchase it. That was not one of GM's best designs, the 6.2 L diesel. My first one was well cared for, but still at 100 K it was totally worn out on the top end, and the engine had to be replaced with a factory crate engine.

The Standine injection pump system used on the 6.2 was marginal at best. A Raycor fuel filtering system goes a long ways to keeping it happy, but even then realize it is expensive to service and replace if needed.

Also be sure that if it has the THM 700 R4 tranny that it is working well. They were worse than the engine in those early years. I had two major rebuilds on mine, and finally took it out and put an old reliable THM 400 in.

Just realize that because it is a Diesel it is not always good. And GM has made some poor ones as well as some excellent ones. I put the 6.2 L into the marginal ones. And a 1985 is now 30 years old.

My opinions only, you understand. I did tow a lot with mine but not without issues.

[dznf0g]

Originally Posted by choctawmel

I lost 4mpg in my Dodge Cummins when the ULSD came out

This makes no sense to me....I'd look for another cause of reduced mileage. Sulfur doesn't affect mileage. It was just a natural "contaminate" in petroleum. It did have the benefit of helping with fuel system lubrication. But burning sulfur results in sulfur dioxide, and other sulfur compounds Usually referred to as sulfuric acid in "shop Jargon", out the tailpipe....a major cause of smog and acid rain.

Each time sulfur content was reduced, by EPA mandate, QUALITY fuel blenders added lubricants to the fuel stock. I have seen zero lack of lubrication issues in the field with LSD or ULSD.

[wxbuoy]

I use stanadyne lubrocity formula in mine; both RV and truck. It makes up for the low sulphur fuels today.


Sent from my iPhone using Airstream Forums

[jcl]

Originally Posted by dznf0g

This makes no sense to me....I'd look for another cause of reduced mileage. Sulfur doesn't affect mileage. It was just a natural "contaminate" in petroleum. It did have the benefit of helping with fuel system lubrication. But burning sulfur results in sulfur dioxide, and other sulfur compounds Usually referred to as sulfuric acid in "shop Jargon", out the tailpipe....a major cause of smog and acid rain.

Each time sulfur content was reduced, by EPA mandate, QUALITY fuel blenders added lubricants to the fuel stock. I have seen zero lack of lubrication issues in the field with LSD or ULSD.

Due to the additional refining, I would estimate the reduced energy content of ULSD at 1% or so. That could result in reduced mileage, but nothing like 4 mpg. The cetane number can be different, and that can have an effect, but again it is minimal. Personally, I would try a different fuel supplier if I saw that much difference.

[RickDavis]

Originally Posted by choctawmel

I lost 4mpg in my Dodge Cummins when the ULSD came out

I might have seen a 1 mpg drop on my 99 and can't even be sure on that. I have over 500,000 miles of fuel tracked in a spreadsheet

[RickDavis]

I have had 2 6.2's an 82 and an 84. Both before they came out with any turbo charged versions.
While they always got me where I was going they were underpowered and also would make lots of black smoke at high altitudes out west.

The 82 was traded for the 84.The 84 died of a broken crank somewhere shy of 200k miles
I agree that it was a marginal engine at best.

The Cummins has proven to be bombproof.

[dznf0g]

Originally Posted by jcl

Due to the additional refining, I would estimate the reduced energy content of ULSD at 1% or so. That could result in reduced mileage, but nothing like 4 mpg. The cetane number can be different, and that can have an effect, but again it is minimal. Personally, I would try a different fuel supplier if I saw that much difference.

I am no refining expert by any stretch, but I was told (during hydrogen fuel cell training) that refiners just introduce hydrogen to the fuel (gas or diesel) which combines with the sulfur molecules to produce hydrogen sulfide, which is easily removed at that point. I don't know if that qualifies as "additional refining", but I don't think it involves further "cooking", if that's what you mean by refining.

BTW, the fuel cell training was about the extra hydrogen, not used for fossil fuel conditioning, would offset for hydrogen fuel use.

[dznf0g]

OK, I looked it up....and I don't understand a lick of it, but it is gassed off:


"Process description[edit]
In an industrial hydrodesulfurization unit, such as in a refinery, the hydrodesulfurization reaction takes place in a fixed-bed reactor at elevated temperatures ranging from 300 to 400 °C and elevated pressures ranging from 30 to 130 atmospheres of absolute pressure, typically in the presence of a catalyst consisting of an alumina base impregnated with cobalt and molybdenum (usually called a CoMo catalyst). Occasionally, a combination of nickel and molybdenum (called NiMo) is used, in addition to the CoMo catalyst, for specific difficult-to-treat feed stocks, such as those containing a high level of chemically bound nitrogen.

The image below is a schematic depiction of the equipment and the process flow streams in a typical refinery HDS unit.


Schematic diagram of a typical Hydrodesulfurization (HDS) unit in a petroleum refinery
The liquid feed (at the bottom left in the diagram) is pumped up to the required elevated pressure and is joined by a stream of hydrogen-rich recycle gas. The resulting liquid-gas mixture is preheated by flowing through a heat exchanger. The preheated feed then flows through a fired heater where the feed mixture is totally vaporized and heated to the required elevated temperature before entering the reactor and flowing through a fixed-bed of catalyst where the hydrodesulfurization reaction takes place.

The hot reaction products are partially cooled by flowing through the heat exchanger where the reactor feed was preheated and then flows through a water-cooled heat exchanger before it flows through the pressure controller (PC) and undergoes a pressure reduction down to about 3 to 5 atmospheres. The resulting mixture of liquid and gas enters the gas separator vessel at about 35 °C and 3 to 5 atmospheres of absolute pressure.

Most of the hydrogen-rich gas from the gas separator vessel is recycle gas, which is routed through an amine contactor for removal of the reaction product H
2S that it contains. The H
2S-free hydrogen-rich gas is then recycled back for reuse in the reactor section. Any excess gas from the gas separator vessel joins the sour gas from the stripping of the reaction product liquid.

The liquid from the gas separator vessel is routed through a reboiled stripper distillation tower. The bottoms product from the stripper is the final desulfurized liquid product from hydrodesulfurization unit.

The overhead sour gas from the stripper contains hydrogen, methane, ethane, hydrogen sulfide, propane, and, perhaps, some butane and heavier components. That sour gas is sent to the refinery's central gas processing plant for removal of the hydrogen sulfide in the refinery's main amine gas treating unit and through a series of distillation towers for recovery of propane, butane and pentane or heavier components. The residual hydrogen, methane, ethane, and some propane is used as refinery fuel gas. The hydrogen sulfide removed and recovered by the amine gas treating unit is subsequently converted to elemental sulfur in a Claus process unit or to sulfuric acid in a wet sulfuric acid process or in the conventional Contact Process.

Note that the above description assumes that the HDS unit feed contains no olefins. If the feed does contain olefins (for example, the feed is a naphtha derived from a refinery fluid catalytic cracker (FCC) unit), then the overhead gas from the HDS stripper may also contain some ethene, propene, butenes and pentenes, or heavier components.

It should also be noted that the amine solution to and from the recycle gas contactor comes from and is returned to the refinery's main amine gas treating unit."

[jcl]

Lessons learned from the introduction of ULSD back in 2007. Key take aways: Check filters, don't add oil to the fuel, lubricity is reduced but has to meet established ASTM standards, so refiners add lubricants.


http://www.landlinemag.com/Magazine/...s-learned.aspx

[jcl]

Originally Posted by dznf0g

I am no refining expert by any stretch, but I was told (during hydrogen fuel cell training) that refiners just introduce hydrogen to the fuel (gas or diesel) which combines with the sulfur molecules to produce hydrogen sulfide, which is easily removed at that point. I don't know if that qualifies as "additional refining", but I don't think it involves further "cooking", if that's what you mean by refining.

I think of refining as purification. The hydrogen is introduced in a reactor (I didn't know the temp, but also looked up that it is at 300-400 C), so that is cooking. It isn't fractional distillation.

Jeff
Also not a petroleum engineer

[dznf0g]

Yeah, Jeff, I read that in the "stuff" in my post above. But it says the feed stock is already pre-heated. They don't say what temp it is at that point, but it looks like it it heated additionally. Also JCLs post indicates a .1 to .2 mpg dropoff for most users (big trucks?).
So on most of the old pickups that averaged, say 23mpg solo:
1% = .23 mpg
3% = .69 mpg

[tjdonahoe]

All diesel fuel now made is the low sulphur, clean fuel, it is very good and it is clean.My big truck now has 1355000 miles and still on the original injectors.The old style fuel was dirty , would jell at 20 degrees, sulphur would cause leaky valves,not good. The 6.2 chev diesel is not a good engine for towing ,they're underpowered and mostly obsolete ....