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Discussion Starter · #1 ·
The literature on the diesel is kind of confusing. Will using B20 void the warranty?

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First the link states -

"A maximum blend of 5% biodiesel meeting ASTM specification D975 is recommended. If frequent operation with biodiesel blends greater than 5% but not greater than 20% (B6 to B20) is desired, a shorter interval maintenance schedule is used:
• Oil change at 10,000 miles (B5 biodiesel fuel) • Oil change at 8,000 miles (B20 biodiesel fuel)"

Later it's stated -

"Ultra-low sulfur diesel (ULSD) required
B5 (5% maximum biodiesel approved)"

So recommended is B5 but it sounds like up to B20 is allowable as long as you change the oil more frequently according to the first quote. The second quote makes it sound maximum approved is B5.

Confused ... :)
 

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JGC Overland
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I'm a diesel newbie. Where do I find this B number, is I right on the pump?
 

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As I said in another thread:

They are saying running up to B5 will be fine, but when you start hitting B20 you will need to start taking into account the need to change/monitor your oil often.

Failing to do so could have rather unpleasant consequences for your engine (and thusly... warranty)

I can go into the gory details of why if you want.
 

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Discussion Starter · #5 ·
So it doesn't automatically void the warranty to use B20 but a guy should keep a close eye on the oil level and change at 8,000 miles ... I just want to know if they technically allow B20 and it doesn't automatically void the warranty. There's no B5 around here but generally only B20.
 

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Well... short of draining your tank and testing... there's no way for them to know...

The Computer may have some info, (as Bio has a lower flashpoint, and thus, less energy) but, that's about it.

Otherwise, they will know if you go into Hydrolock.

The dealer may note that you have extra crankcase oil when you change it, but, that would happen if you have any B value fuel (which, most stations around here are running atleast B5).
 

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Correction, biodiesel has a higher flashpoint (temperature at which it ignites).

The "less energy" can mean a couple things. The calorific energy density of biodiesel is lower than petrol. But it can also refer to the amount of useable energy extracted by the engine, which is a function of efficiency of combustion.

[rant] There are claims in both directions about how biodiesel performs on this front. A lot depends on engine design, which are presently optimized toward petrodiesel. Fuel sensors and adaptive tuning are in the development pipeline, but for now, the focus seems to be on fleet shipping trucks. Meanwhile, consumer vehicles will continue down the path of lower complexity/cost/flexibility. [/rant]

Anyway, the cold comfort is no fuel-sensor forensic trail to bite you during the maintenance nightmare that will result if you fail to follow the guidance.

Well... short of draining your tank and testing... there's no way for them to know...

The Computer may have some info, (as Bio has a lower flashpoint, and thus, less energy) but, that's about it.
 

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Correction, biodiesel has a higher flashpoint (temperature at which it ignites).
Doh... right.

Meant Higher. :p

Basically, it is injected post combustion and if it was normal diesel, it would ignite in the system, but as it's Bio and has the higher flashpoint, just sticks to the cylinder wall/piston and will make it's way into the crankcase oil as a result (bad juju occurs at this point).

If you fail to keep a close eye on your oil levels, you will eventually end up with too much oil. That will eventually end up with (if left uncorrected) in Hydrolock and thusly, bent rods (if you are lucky).

If you have access to cheap and plentiful CRD approved oil (low ash), you can run B100 in this thing. However, you will be changing your oil every few thousand miles (maybe a few thousand)...
 

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Funny to hear all this about biodiesel. I ran b100 in my TDI (with a PD, not common rail, engine) and I never had issues with too much oil in the crankcase. I ran it for every season but winter when I switched to b20. Over 5 years and nearly 80k miles worth. Are the CRD and PD engines that different? I'd be interested to hear what TDI guys are doing since I believe they are now common rail diesels, correct?
 

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Here ya go:

2007+ Diesel Emissions & Biodiesel; Not All That Rosy | Utah Biodiesel Supply Blog

I've had a couple TDI and CRD engines (in a VW and a Merc). And I ran B100 in them just fine and was ready to buy one of these little processors to make my own happy juice.

...right up until I read this article.

You could still run a higher B value diesel, but you will have to keep a close eye on your oil and change it often (unless the Jeep engine is rigged up differently, but I can't find much info on that front).
 
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Here ya go:

2007+ Diesel Emissions & Biodiesel; Not All That Rosy | Utah Biodiesel Supply Blog

I've had a couple TDI and CRD engines (in a VW and a Merc). And I ran B100 in them just fine and was ready to buy one of these little processors to make my own happy juice.

...right up until I read this article.

You could still run a higher B value diesel, but you will have to keep a close eye on your oil and change it often (unless the Jeep engine is rigged up differently, but I can't find much info on that front).
Ouch. Sounds harsh but also like there could be a solution in the future. For now, I'll be avoiding any biodiesel. I mean, when I finally get to actually drive my yet-to-be-ordered CRD. :lol:
 

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Most places around here run B5-B20... so I can't avoid it.

I figure I'll just keep an eyeball on the oil and take her in for a change every 8-9k.

There are ways around it, but, I'm sure as hell not cutting into my brand new $50k Jeep, and am a touch unnerved at the idea of flashing the computer (screw that up and you just bricked your car...).
 

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I've used B99 in the summer months and various blends during colder temps with our 2008 CRD and have had no fuel-related issues or too much oil in the crank case and I'm at 130,000 miles.
 
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