Diesel Fuel Additives

dieselenthusiast · **Posted:** Fri Mar 04, 2011 1:57 am

crdmom wrote:

I don't add Red Line to every tank, usually every 3. I am sure it would be awesome to add to every tank but just don't have that kind of cash. Especially with diesel prices right now. But I can definitely tell the difference if I go a little too long.

Supposedly the product will pay for itself. They say that you save more money in fuel savings than what the product will cost. I’m not sure how true that is, but that’s what Power Service and Amsoil advertise. :mrgreen:

bhc04 · **Posted:** Fri Mar 04, 2011 11:42 am

I've tried them all and to tell you the truth, I can't tell if they make a difference in milage. IMHO, as far as trying to measure a difference, unless you drive the exact same roadway under the exact same weather conditions "everytime", it is "very" difficult to measure if additives make a difference either way. I can say that when I have used them, they've made my CRD run a little quieter than without.

nursecosmo · **Posted:** Sat Mar 05, 2011 10:46 am

None of them will save you money until the price of fuel gets significantly higher than it is now. Some "may" extend IP life but probably not enough to save money. I only use Powerservice White during the coldest winter months to prevent fuel gelling and help at start up. It does help with both but it does not save money with the price of fuel where it is at present. It is all a matter of math.

WWDiesel · **Posted:** Wed Nov 27, 2019 10:56 am

Just in case anyone missed this and was not sold on using Diesel Kleen additives in their diesel fuel:

Cummins Inc. Officially Recommends Power Service Diesel Kleen +Cetane and Diesel Fuel Supplement +Cetane Boost For Optimized Engine Performance
https://www.cummins.com/news/releases/2 ... cetane-and

PZKW108 · **Joined:** Sun Apr 06, 2014 5:23 pm **Posts:** 461

theirishman wrote:

Howdy to all.

The main killer of a Cat Converter is oil. Using 2 stroke oil may just do that for you.

Use a good quality fuel, especially when it is cold.

I'm not recommending 2 stroke oil in the CRD but any kind of diesel additive to bring the lubricity to Bosch standards
as the diesel at the pump in north America doesn't meet !

https://ww3.arb.ca.gov/fuels/gasoline/m ... 3bosch.pdf

thesameguy · **Joined:** Sat Oct 01, 2016 8:24 pm **Posts:** 652

That is a cool document, but VERY old!

WWDiesel · **Posted:** Wed Nov 27, 2019 1:50 pm

PZKW108 wrote:

theirishman wrote:

Howdy to all.
The main killer of a Cat Converter is oil. Using 2 stroke oil may just do that for you.
Use a good quality fuel, especially when it is cold.

I'm not recommending 2 stroke oil in the CRD but any kind of diesel additive to bring the lubricity to Bosch standards
as the diesel at the pump in north America doesn't meet !
https://ww3.arb.ca.gov/fuels/gasoline/m ... 3bosch.pdf

I use a mixture of Diesel Kleen, Marvel Mystery Oil, and non-synthetic 2-cycle oil at every fill up.
I have NO CAT on my diesels, got rid of them years ago. Worthless pieces of junk that only cause restrictions and adds backpressure to the turbo along with internals starts rattling with age.

thesameguy wrote:

That is a cool document, but VERY old!

Yes, I know it was a little dated, but it was being debated on a Cummins forum and figured it was good information for those who may not have ever seen it. :idea:

thesameguy · **Joined:** Sat Oct 01, 2016 8:24 pm **Posts:** 652

I think you might be overestimating the deleterious effects of a cat. I have three nicely tuned turbocharged cars. On the last dyno pass, the XR4Ti made 320hp without a car, and 308hp with a cat. 3% loss on a 3" Magnaflow. Not even worth worrying about.

Somewhat related, you do NOT want a vacuum behind a turbo, certainly not a factory turbo. "Negative backpressure" is particularly bad for journal bearings. IME, you're 100% better served with a sizeable downpipe to handle post-turbo exhaust expansion (and create a big volume+pressure differential) than by removing the cat. Removing the cat from a modern car does little to nothing.

That was good for 33hp on 20psi.

Removing the cat (another 3" Magnaflow…) netted 8.

WWDiesel · **Posted:** Wed Nov 27, 2019 3:22 pm

Anything you can do to lower backpressure on the exhaust side of the turbo i.e. larger exhaust, removal of the CAT, straight through muffler, etc... helps improve turbo response time and lowers EGT's leaving the combustion chamber. All proven facts. I have actually proved this myself on my Dodge Cummins since it has an EGT gauge. I don't make this stuff up, plenty of information and reading online about the effects of lowering turbo back pressure with free flowing exhaust systems, removal of CAT, etc....
But if you like your CAT's, keep them, it's your vehicle, as for me, don't like them.

PZKW108 · **Joined:** Sun Apr 06, 2014 5:23 pm **Posts:** 461

thesameguy wrote:

I think you might be overestimating the deleterious effects of a cat. I have three nicely tuned turbocharged cars. On the last dyno pass, the XR4Ti made 320hp without a car, and 308hp with a cat. 3% loss on a 3" Magnaflow. Not even worth worrying about.

Somewhat related, you do NOT want a vacuum behind a turbo, certainly not a factory turbo. "Negative backpressure" is particularly bad for journal bearings. IME, you're 100% better served with a sizeable downpipe to handle post-turbo exhaust expansion (and create a big volume+pressure differential) than by removing the cat. Removing the cat from a modern car does little to nothing.

That was good for 33hp on 20psi.

Removing the cat (another 3" Magnaflow…) netted 8.

A agree with you here.

The other thing is the cat IS the only emission control that really do a appreciable job without compromising performance and at a reasonable price and useful life.

The first thing you will notice if you remove your cat is the smell, it will stink...…

Unless you are tuning high performance offroad engine removing the cat is not advise and also illegal !

iakj11 · **Posted:** Wed Nov 27, 2019 8:45 pm

What is the useful life of the cats on our CRDs? Any suggested preventative maintenance?

thesameguy · **Joined:** Sat Oct 01, 2016 8:24 pm **Posts:** 652

Cats are by design forever. Nothing is used up when a catalytic converter works so in theory it will last forever.

What does a cat in on modern engines is contamination. Oil contamination is the worst - so if you have a leaky valve stem seals or a PCV problem, oil will coat the cat and ruin it. During a head gasket failure coolant contamination can do it. On older cars - not so much cars in the last 20-30 years - cats can overheat and melt when unburned fuel gets into the exhaust.... on a modern engine with modern fuel injection, that's not only unlikely but probably you'll have a bunch of warning lights going off too.

Since it's only broken stuff that will take a cat out, the lifetime of a cat is really a matter of how well you keep up your engine. On OBDII cars, the only time I have ever replaced a cat is when something has gone wrong... one of the aforementioned contamination scenarios.

Edit: I wanted to add for completeness that there are example of "cheap cats" that do wear out. A lot of aftermarket cats (often couched as "racing cats") are famously referred to as "two year cats" due to their tendency to wear out after two years. These cats have low volume substrates with lower densities of the precious metals... these cats become contaminated extremely easily, so abuse a regular OE cat can put up with for a decade or more kills these things quickly. There are some examples of OEs cheaping out too.... VW is one that comes to mind. The Feds made them extend their warranty to 10 years. The default Federal warranty is only 8.

thesameguy · **Joined:** Sat Oct 01, 2016 8:24 pm **Posts:** 652

PZKW108 wrote:

The other thing is the cat IS the only emission control that really do a appreciable job without compromising performance and at a reasonable price and useful life.

That's where I'm at. Back in the '70s thermal reactors were iffy, and in the early '80s those bead converters were annoying and power-robbing. But "modern" substrate cats are durable, reliable, and have no functional impact on power. All win!

PZKW108 · **Joined:** Sun Apr 06, 2014 5:23 pm **Posts:** 461

thesameguy wrote:

PZKW108 wrote:

The other thing is the cat IS the only emission control that really do a appreciable job without compromising performance and at a reasonable price and useful life.

That's where I'm at. Back in the '70s thermal reactors were iffy, and in the early '80s those bead converters were annoying and power-robbing. But "modern" substrate cats are durable, reliable, and have no functional impact on power. All win!

100% agree !!!

iakj11 · **Posted:** Thu Nov 28, 2019 9:51 am

thesameguy wrote:

Cats are by design forever. Nothing is used up when a catalytic converter works so in theory it will last forever.

What does a cat in on modern engines is contamination.

Thanks for that explanation. Makes sense. I've been messing with my exhaust lately and couldn't help but notice all of the soot in places. Thought maybe it could eventually plug up the cat on a diesel. When I view the cat innards from the outlet side, the visible layer of mesh looks intact, unplugged and surprisingly not black. Sounds like the best pm is keeping oil and coolant out.

thesameguy · **Joined:** Sat Oct 01, 2016 8:24 pm **Posts:** 652

I noticed exactly the same thing. I am actually surprised at how clean the exhaust is on my 180k Jeep. I have had gas cars with exhausts in worse shape at that mileage. Considering how sooty the intake system is, finding a totally clean exhaust was a shock!

Diesel Dan · **Posted:** Thu Nov 28, 2019 2:00 pm

thesameguy wrote:

Cats are by design forever. Nothing is used up when a catalytic converter works so in theory it will last forever.

What we were taught in GM training is that they don't die but you can kill them.

When I do the repower on my 1980 Monza it is going to get a high flow CAT as well.
I started working in the shops when CCC was still common. The air quality inside a operating shop has greatly improved over the last 30 years.

thesameguy · **Joined:** Sat Oct 01, 2016 8:24 pm **Posts:** 652

Yeah, CCC and cats weren't a good match, but fuel injection tech and converter tech is pretty well sorted today. For the amount of money involved the contribution to environmental well being seems like a no brainer, but just not having to smell the exhaust is enough motivation for me. Switching back and forth between newish cars and '60s cars, it's hard not to think about how awful old cars smell. As money allows, I will definitely repower my Falcon and Fleetwood with modern engines with modern emissions controls.

Edit: Also, share some pics of that Monza! They were so cool looking! Possibly my second favorite modern GM small car... I have always been partial to Fieros.

Steve777 · **Joined:** Fri Oct 16, 2015 11:31 pm **Posts:** 279

I am fairly late to this thread, but wanted to throw in my 2 cents...

The best "additive" for lubrication is hands down biodiesel. Also the cheapest at maybe 20-50% more then petro diesel. Chrysler and VW used to add bio to the tanks (at like 2%) from the factory, and may still do so. The main problem with bio is that it does gell in cold weather, much sooner than blended petro diesel will. But at like $4/gallon one can use it much more frequently than the bottled products.

I play chicken with the weather and run about 20% bio in the winter here, but 5 or 10% bio would likely be safe down to -10F. I view it as cheap protection for the IP and injectors.

PZKW108 · **Joined:** Sun Apr 06, 2014 5:23 pm **Posts:** 461

Steve777 wrote:

I am fairly late to this thread, but wanted to throw in my 2 cents...

The best "additive" for lubrication is hands down biodiesel. Also the cheapest at maybe 20-50% more then petro diesel. Chrysler and VW used to add bio to the tanks (at like 2%) from the factory, and may still do so. The main problem with bio is that it does gell in cold weather, much sooner than blended petro diesel will. But at like $4/gallon one can use it much more frequently than the bottled products.

I play chicken with the weather and run about 20% bio in the winter here, but 5 or 10% bio would likely be safe down to -10F. I view it as cheap protection for the IP and injectors.

Yes biodiesel is the best by far, I wish I could found some around here. I would probably still use other additive for the winter !

Diesel Fuel Additives

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