This is kinda long but might be worth your time. I reviewed the report from the EPA and pulled out some quotes I felt were key. They are below. The full report is in a thread under my name dated 12/19. Let me be clear that the engine and vehicle they used for the test were small and have no direct comparisons to out trucks. But the biodiesel and the DPF regenerations and the late fuel injections to burn out the dpf do. If you want an even better idea of the impact of the bio versus ULSD find figures 6 and 7 in the report (pages 5 and 6). If you don't want to do that I will tell you that the difference is dramatic in that the bio dilutes the oil as much as 3 times what ULSD does. Another finding in the study was that the age of the oil was more critical to it's degeneration than was the bio dilution. Probably why most of us are on an excellerated change cycle, we just sensed that to be true. The following are all quotes lifted from the pamphlet.

"Despite these observed biodiesel oil dilution levels, there were no observed impacts on the performance of the engine or the emission control system"

"Acceptable oil dilution limits for original equipment manufacturers (OEMs) range up to 50%, but most OEMs want limits to be much lower."

"However, because biodiesel has a relatively higher distillation temperature and boiling point, when it is present in post-injected fuel it tends to dilute the oil on a level disproportionate to its blend ratio in the fuel. This leads to a concern about oil dilution"

"These late injection events increase the opportunity for unburned fuel to reach the cylinder walls and in turn enter the lubricating oil. With conventional diesel fuel it can boil out of the lube oil, minimizing long-term dilution effects. However, this effect is accentuated with biodiesel because of its high boiling point relative to petroleum diesel, which can lead to a disproportionate amount of fuel being retained in the lube oil."


"DPF regeneration is occasionally required in order to oxidize the accumulated soot that collects on the DPF during normal engine operation. late in-cylinder fuel injection is used to create the high temperatures over the DPF required to burn or oxidize the accumulated soot. This provides another opportunity for increased oil dilution."


"After the completion of the durability tests for the NAC and the SCR system, the engine had undergone an accelerated aging schedule representative of twice its useful life, or approximately 240,000 miles. At the conclusion of the project, the engine was disassembled and each component was carefully analyzed. All moving parts such as bearings, pistons, and piston rings were inspected and measured. None of the components of the engine, including the injectors, showed signs of excessive wear or other signs of deterioration as a result of the extended biodiesel operation. The flow characteristics of the injectors remained comparable to levels noted before the start of the durability study."

"There were no obvious biodiesel specific effects on used lube oil properties, and most changes appeared to be consistent with normal lube oil aging."

 

Stay away from bio...

In short, it does not burn as effectively as diesel.

Can have more water in it which leads to some expensive repairs that the EPA won't cover.

Leads to more regens, thereby causing more fuel in the oil.

Costs the same as get poorer MPG's.

 

Understanding the Post-Injection Problem - Biodiesel Magazine

Here's another impact on Biodiesel can have in which it competes with the zinc in your oil on the lubricating surfaces in your engine. I'm not sure how this article was verified, but it could serve as a warning when using Bio especially in a post injection engine like the 6.4.

 

Yeah, I found that one today also. I am convinced that biodiesel will at best increase oil dilution and at worst break down the lubricating additives in the oil. So, OK you say avoid it and I would love to but how do I do that in those corn states? Do the 18 wheelers run bio? Can I avoid it by fueling at the truck stops? It's a hassle but I woud do it to avoid the bio.

 

There's a few web sites that advertise fuel stations/company's that sell bio diesel so maybe research this.

Yes they do

Again research which truck stops/fuel stations/company's sell bio. For example there's a Company in Texas "Loves" truck stops that sells B5 and these "Loves" truck stop's are always full of 18 wheelers fueling up.

 

Wonder what technology the 18 wheelers use to regen the DPF. There is a lot better system with an extra injector down in the exhaust pipe. I think that's what the 6.7 uses and also the new Duramax motors. If that's the case they wouldn't have a problem with oil dilution from the bio. At least that's the way I've read the articles. Both the EPA study and the article in Diesel magazine. I've fueled at Loves many times and never noticed they were B5, of coursse it didn't matter with my old truck.

 

The Duramax uses a ninth injector and the 6.7 uses the same method as the 6.4. As for the 18 wheeler's I've yet to see one with a DPF on it, however I have noticed them on some of the medium duty trucks.

I believe Love's just started using B5 this year, but it could be a local thing.

 

Class 8 trucks have to meet the exact same standards our pickups to for diesel emissions.

EVERY tractor made after January 1st, 2007 has a DPF. You can't see it because it's under the truck and normally hidden by the fuel tanks, but trust me it's there.

You'll notice that Freightliner Cascadias often have the exhaust exiting after the cab facing the ground, these are DPF systems.

Also, Pete 389s have larger (5"?) exhaust tips and vent ports just above the muffler; this has a similar effect as the exhaust tip on the '08+ PSD trucks.

 

Are you sure, the 18 wheeler tractors don't have to have DPFs. I thought they did. No wonder the EPA is having such an easy time pushing us around, the're aren't very many of us and we don't have anyone to lobby for us. Darn, now it makes sense. I wondered why the big trucking companys were taking it so calmly.

 

Looks like Tom answered your question. I guess the trucks that come to mind are pre 07 18 wheelers. I suspect these trucks will stay on the road for years to come with new engines just to avoid the DPF stuff.

 

I've been out of the industry for nearly a year, but this is exactly the sentiment in every company I've seen.

Lots of companies have loaded up on '06 trucks and parked them until they needed to rotate them in. One company I drove for had brand-new 2006 trucks that had never seen the road as of last year!

Modern diesels are expensive and inefficient compared to the pre-emissions trucks!

 

I repeat my amazement that the trucking companys didn't put up a fight. I guess they didn't want the anti "green" label. But if the impact on them is anything like it is on us then their cost have to go up. Which of course they just pass on so we pay for it anyway.