Do I need a fuel additive?
 

A question for the diesel forum. Before the industry started offering ULS diesel fuel (low sulfur), I used B20 biodiesel blend in my 2000 NB tdi, and enjoyed the benefits of increased lubricity, and smoother operation over the "dirty fuel" commonly used until 2008/2009 period.
Now I drive a Q5 tdi, using the cleaner ULS fuel, and wonder if I need to use an oil additive to counter the lower sulfur "lack of lubricity" claimed by many. Does anyone have an opinion on this?
I'm not a high mileage driver (8m-10m miles/year), but I do want my tdi to have the best drink that is practical.
Thanks for your learned opinion.
Tenderfoot

I don't know enough about American fuel to help, it seems insane that a new car in this day and age would need some sort of additive, but then again people changing their fuel 10 times more often that required also seems insane but that doesn't stop people doing that either...

Have you asked the Audi dealer you bought the car from?

You could ask the diesel station if the fuel they sell had the lubricants added back in. It appears farmers and others that buy off road in bulk have the choice of them added or not. So somebody should know if the station has them or not.

Or just use B5(the max I think for Audis)if available. B1 might even be enough biodiesel to overcome any lack of lubricants in the diesel.

Good idea troll bait, but typical fuel stations in our part of the woods, don't know additives, cetane, ppm sulfur or anything except "the rest room is around the corner......that'll be $68.59 please".
The folks at Audi forbid the use of any biodiesel at any level, or else risk the warranty. I hate to get back to the blending myself stage as quite frankly the fuel stinks, and the wife doesn't like it in the attached garage. The car runs so smooth and effortllessly, that I think I'll go with it straight from the pump. I would appreciate any user (bioD) comments if any one has tried it with a new tdi.
Comments?
Tenderfoot
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Engines and fuels ate more or less designed for each other. I find it impossible to believe VW (owners of Audi) didn't design their engines and fuel systems to work satisfactorily on the fuel available in the market where they sell the cars. Odds are the owner's manual has some phraseology about additives being unneeded.

The older diesels should use lubricity additives to make up for what has been lost in the newer cleaner fuels. If you diesel was designed for the newer stuff than it should be fine.


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You say above you wonder if you need to use an oil additive in your Q5 to counter the lack of lubricity in ULSD. Did you mean to say fuel additive ?
I do use a fuel additive in my 2011 Golf TDI but more as an insurance policy to increase the fuel lubricity. I use no additive in the oil.

It can happen that engineers don't design for the fuel...a fairly recent example was the Ford Powerstroke 6.0l where Ford's team somehow overlooked the quality of diesel fuel here. I believe that is what caused most of the nightmare scenarios that engine had. I believe Audi engineers are more savvy and you shouldn't need any additives. Having said that, a bottle of Lucas or some Diesel Kleen may not be a bad idea now and then. Won't hurt anything but your pocketbook.

Cogeneration, you are SO right, I meant a fuel additive, not oil as you noted. Guess that one is due to my CRS desease. ULS fuels have nothing to do with synoils for TDi's. Looks like the forum is probably right in that the Audi guys don't think it's needed either. Guess it's the throwback to the early 2000's with our stink fuels. Might try a FUEL additive to see if I see any mpg change. Thanks to all for their comments.
Tenderfoot

Way back when I had my Diesel, I worried about additives for winter use. Normally, stations sold #2 Diesel in summer, and "winterized" #2 in winter. #1, which is actually winter diesel, was harder to find. There were and are additives, usually used at about 1%, said to keep #2 fuel from gelling. As it turned out, the additive cost per gallon was just about the same as the difference in price per gallon between #1 and #2. I used #1 when I could, simply because I didn't have to worry whether the additives worked. If you end up using some sort of additive, keep careful records to see whether it really does result in any improvement in mileage. Then figure whether the improvement in mileage pays for the additive. Remember there is considerable variation tank-to-tank, which might well "swamp" any changes caused by any additive.