Are Diesels Really "Oil Burners"?

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Just test drove a BMW 335d today and loved it! What a rush! I have several reservations though.1)I've heard diesels referred to as "oil burners".If that was ever been true is it true of today's European diesels (BMW,VW,Audi,etc)? 2)Unrelated to oil...is it true that diesel fuel can be problematic in cold weather (New England winters),making them difficult to start? Also,it looks like BMW recommends oil changes every 15K miles.If I pull the trigger here would it be wise to go,say,every 6 months/7.5K miles? TIA!
 

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The "oil burner" name is because diesel fuel is referred to as an oil. Diesel fuel and Furnace oil are very similar...... If you use a fuel conditioner and anti-gelling agent like Stanadyne regularly, you won't have winter issues.
 
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Most diesel supplied in the winter months has a mix of #1 and #2 diesel. #2 diesel is used in the summer months and generally has more btu of energy in it resulting in better fuel economy. #2 diesel is more prone to gelling in the colder months however. #1 diesel, on the other hand is less prone to gelling but has fewer btu of energy. Usually you can expect fuel economy to go down a little in the winter with a diesel engine. I drive a diesel truck and reside in Michigan which gets cold at most winters and have never had an issue with hard starts due to fuel gelling in the winter months. On a few especially cold weeks I can remember seeing semi-trucks that drove up from Florida or something and their fuel gets all gelled up.
 
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 Originally Posted By: JimFitzpatrick
... Also,it looks like BMW recommends oil changes every 15K miles.If I pull the trigger here would it be wise to go,say,every 6 months/7.5K miles? TIA!
I think that would be wise... Those 15K mile OCI's seem a tad bit ridiculous. Oil is cheap, BMW engines aren't! If you really want to go 15K I would seriously do UOA's frequently for the first little while and see what kind of wear metal, TBN/TAN trends develop. I would think it wouldn't be very pretty. Acceptable, but not pretty. ;\)
 
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I've seen a lot of great used-oil analyses (UOA) on TDI engines with a 10k-miles oil change interval. That's with a 4.5-5.0 quart sump capacity. If the BMW 335d engine has a bigger sump, then a 15k-mile OCI seems reasonable. You can test to be certain.
 
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They're called oil burners because in the old days (mechanical injection pumps) you could run a diesel on just about any oil you could find-unfortunately, the newer ones are a lot more picky!
 
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u can use p50 diesel fuel which is winter diesel and wont congeal in -40f p20 is the summer fuel and will turn to jell in the cold weather
 
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Diesel fuel is an oil. Put a turbo on a diesel and it will get up and go!!! And get better mpgs than a gasoline engine.
 
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 Quote:
true that diesel fuel can be problematic in cold weather
Diesel fuel contains some wax. No problem except below about +20°F when the wax particles solidify and gum together. They can plug up the fuel filter. Anti-gel chemicals work very well to keep the wax particles so small that they pass through the filter, and your engine runs great. Some fuel stations sell the fuel with the additive in it. #1 diesel fuel, closely related to kerosene, has very little wax so is often blended with #2D in the winter. #1D has fewer BTUs of energy per gallon so you lose fuel mileage, but it burns fine in the engine. Just to be clear, #1D is not a better fuel, it is just different. Lots of folks use the old term "diesel oil" instead of the more accurate term "diesel fuel." Diesel fuel, especially years ago when it came from simple refinery distillation, was more like a very thin oil than a fuel like gasoline.
 
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The BMW diesel has an 8 qt oil capacity. It call for ACEA A3/B4/C3 rated oil, also BMW LL-04. Synthetic, in other words, like Mobil 1 ESP 5W-30 or the Castrol they sell at the dealership. All modern BMW motors have a fairly large capacity, our 01 325xi 2.5L also holds 8 qt. We have an X5 35d here in Anchorage, since about 1/1/09. When I first got it I left out all night at -15 F. and it started instantly the next AM. Of course in Alaska all the gas stations sell straight #1 all winter. Fuel mileage goes up 1-2 mpg in the summer due to heavier fuel and warmer drivetrain lube. The X5 does 21.5 mpg in city driving here, not bad for >5000 lb SUV. I think the 335d would do 27 mpg or better in city driving, 36-40 mpg highway. Charlie
 
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 Originally Posted By: StevieC
 Originally Posted By: JimFitzpatrick
... Also,it looks like BMW recommends oil changes every 15K miles.If I pull the trigger here would it be wise to go,say,every 6 months/7.5K miles? TIA!
I think that would be wise... Those 15K mile OCI's seem a tad bit ridiculous. Oil is cheap, BMW engines aren't! If you really want to go 15K I would seriously do UOA's frequently for the first little while and see what kind of wear metal, TBN/TAN trends develop. I would think it wouldn't be very pretty. Acceptable, but not pretty. ;\)
15K OEM intervals are not out of line. My Jeep Liberty 2.8L with a 6.5 qt oil capacity is getting OEM recommended OCI's around 12K with no problems (did a couple of UOA's to check). The new DD15 engine (a Daimler engine) has OEM recommended OCI's of 50K miles. Diesel engines now, especially the ones with DPF and using SCR, like bluetec, are way cleaner and the oils are holding up longer. ULSD fuel has made a big difference as well.
 
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 Originally Posted By: JimFitzpatrick
Just test drove a BMW 335d today and loved it! What a rush! I have several reservations though.1)I've heard diesels referred to as "oil burners".If that was ever been true is it true of today's European diesels (BMW,VW,Audi,etc)? 2)Unrelated to oil...is it true that diesel fuel can be problematic in cold weather (New England winters),making them difficult to start? Also,it looks like BMW recommends oil changes every 15K miles.If I pull the trigger here would it be wise to go,say,every 6 months/7.5K miles? TIA!
For those not familiar with diesels, you would have to change your way of thinking for sure. But simple measures can prevent real problems. As has been stated, just add a good diesel anti-gel during the winter and make sure you are buying fuel from a solid retailer. Plug the engine in when it gets real cold to help with starting. Make sure and change the fuel filter regularly.... at the very least, just before winter. Even though might seem a pain early on, your dismay at having to do extra things will soon disappear when you look at your average mpg compared to a gasser. Even when diesel spikes above gas prices, you will still be ahead of the game. Diesel would have to be almost 30% more than gasoline to reach a break even point for the end user. Diesel engines, by their very nature of manufacuring and metalurgy, will far exceed the life expectancy of a gasoline engine. Heck, there are still some BMW's and MB's that were manufactured in the 70's running around the countryside and haven't had a major overhaul. You take care of it and watch how you drive it, and a diesel auto will more than pay for itself many times over.
 
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 Originally Posted By: oilyriser
Diesel fuel is safer if you crash and leak a puddle under the car. No crispy critter.
just like charcoal lighter fluid.
 
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Why do you think diesels engines sometimes have such large crankcase capacities? My 2.5L MB 300D holds nearly 8 quarts.
 
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The 15k OCI sounds reasonable. When I bought my 2006 Mercedes E320 CDI it came with a suggested 13K OCI. It has an 8 quart oil capacity and a fleece oil filter. The BMW probably is equipped with a fleece filter as well. I did several UOAs and they came up fine. Good luck with it! Ed B
 
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 Originally Posted By: OVERK1LL
If you use a fuel conditioner and anti-gelling agent like Stanadyne regularly, you won't have winter issues.
I don't know about BMW, but VW recommends NOT using fuel additives in the new TDI engines. The particulate filter is extremely sensitive to additives and the type of oil used (must be low ash). Parts of the fuel system are supposedly heated so that wax does not cause clogging issues in cold months. All new diesels must use ultra low sulfur fuel.
 
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Most of the fuel addtives are DPF friendly. Of course, if you never experience sub-zero weather, you might get by without ever using an additive. Would be a bad day indeed if a gel up occured though. A lot of the '07 and later truck owners are regularly using additives with no problems to the DPF.
 Originally Posted By: gonesurfing
 Originally Posted By: OVERK1LL
If you use a fuel conditioner and anti-gelling agent like Stanadyne regularly, you won't have winter issues.
I don't know about BMW, but VW recommends NOT using fuel additives in the new TDI engines. The particulate filter is extremely sensitive to additives and the type of oil used (must be low ash). Parts of the fuel system are supposedly heated so that wax does not cause clogging issues in cold months. All new diesels must use ultra low sulfur fuel.
 
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The fuel available at almost every diesel pump in the country contains additives of one kind or another. You can pay extra for premium diesel with cetane boosters, or you can buy the regular stuff and add your own. Even in North Carolina, you might want to make sure your fuel is properly winterized next December and January.
 
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