This has been a really informative thread. I have a US spec model in Germany. I just got my "no start in 992 miles" warning, at about the 18,5000 km mark. So I stopped into the local Esso station, and picked up a five liter jug of Ad Blue, with spout. I only filled the active tank, but now that I know the passive tank exists, I know where the remainder is going. The dealer noted the level check as OK at the first annual service, but it may be they too were unaware of the two tank requirement. Good news is the stuff was only 10 Euro for 5 liters.

No Charge
 

Diesel exhaust fluid level warning came on at slightly less than 12K. In for service this morning at 0900, out by 1100. Oil/filter change and 9 liters (so says SA) of diesel exhaust fluid, zip,zap, zippty (sorry KIA) out the door and no charge. Plus free coffee, a car wash and a chance to look at new BMW's, Audi's, VW's and Porsches.

The black on black S type Q7 TDI sure looks good! So does the R8, Panamara and GTS3!

drool.....

Does anybody have any wording from BMW ( website, manual ) that states flush and refill. When I picked up my X5, the dealer only refilled the amount that was used. They did not flush the old DEF fluid and stated that they only refill what is needed. Thanks

bmw used to flush the system, not it is no longer required to flush it, just to top off. reference SIB 16 01 09.

INFORMATION
http://www.bmwtis.net/tiscode/cgi-bin/new.gif Note: It is no longer necessary to drain the active and passive tanks during an oil service. Topping up of both tanks is now the approved method of refilling the system during a scheduled service even if the remaining DEF in the system is over twelve months old. The extraction tool should still be utilized when draining the SCR system during related repairs.

Agree (of course)

I think the truth was that it never was 'technically or practically necessary" but BMW had it in their instructions...so now that they've corrected the documents, it looks like a 'decrease' in service.

On a car that is getting decent use, the old DEF should mix with the new and not be an issue.

Now, if a car goes 2,3 DEF services, over 3,4 years, and you are only using a gallon each time, then you will surely have old fluid. We can argue if new fluid is needed for EMISSIONS or if it will also impact THE VEHICLE. In other words does it degrade to the point of damaging the system, or just reduction in efficiency?

For 99% of the vehicles, simply refilling should be fine

Exhaust Fluid low warning on only after 5000 after oil change
 

So, luckily I had a already scheduled service with BMW for a intermittent AC problem. Second time in for this problem, and they still did not "duplicate the problem."

Anyways, the "exhaust Fluid" warning light came on 2 days prior to dropping off the vehicle. I only have 10600 miles on a 2009 X5 35D. They said the yearly oil change was done around 5600. I know BMW states that depending on the driving habits, but I really don't see using the fluid in half the time it is supposed to last. And what defines aggressive driving? I don't ever floor the vehicle. I drive around 75 on the highway.

BMW wont cover the fluid, so I am force to pay $40 a gallon; putting in only 1 gallon to see how long that will last. At the next oil service I will make sure they top off the fluid fully with the two 2.5 gallon tanks.

So far BMW is not making my satisfied with their lack of duplicating the problem, and lack maintenance covered.

don't pay the $40
 

I and others have posted several times........you can buy the SCR fluid (urea) from any truck or car dealer formunder $10 per gallon......did your paperwork indicate how much fluid they used at the 5600 mile service?

I suspect that your dealer was unfamiliar with SCR fluid on your 2009, and it wasn't filled at delivery.......unless you have a bunch of idle time, you shouldn't have used that much.....

Next time you see a truck dealership (Freightliner, Peterbilt, Kenworth - NOT International) or a Cummins or Detroit Diesel shop.....stop in and buy a jug.....1 gallon, 2.5 gallons, or 5 gallons.......

I put in a gallon early on after I found that the PDC didn't fill mine initially.....I kep a jug in the garage, and have never used in 23000 miles....

Good luck !

Should DEF reserve affect mileage?
 

Or are my expectations for "highway miles" too optimistic?

My DEF warning light came on about 1/3 the way through a 1000+ mile round trip, which was a bit unnerving until I read that I could refill it myself, if necessary. What I did find surprising is that my fuel mileage was atrocious on mostly highway miles, in fact worse than on the same trip in early January during bitterly cold and sometimes blizzard conditions.

I've been tracking my mileage on fuelly.com for most of the time I've had the vehicle, so looking at how it has performed over time is easy enough. Most of the time I'm commuting with 40-50% city driving and averaging high 22 to mid 23 mpg. That seems decent enough as it is as good or better than I was getting in my e92 335i.

On the recent trip we were averaging 80 MPH on I76 and I80 in Colorado and Nebraska, but the X5 couldn't seem to manage more than 22 MPG, which was surprising as I was expecting 25 to 26 MPG. In January when the temps were below freezing, with more people and luggage, and with a strong headwind the X5 was getting 24 to 25 MPG. The only obvious "negative" on this latest trip was that the DEF warning light was on. Maybe the X5 changes the tuning a bit to conserve DEF, negatively impacting MPG?

Or am I simply expecting too much? Maybe 80 MPH is just too fast for the gearing?

I'm not trying to "flame" the X5, so don't get me wrong, but the poor MPG caught me by surprise!

DEF fluid levels won't affect mileage. It is post-treatment, after the combustion process.

The X5 is a bit of a brick. Pushing a brick too quickly through the air will reduce mileage. I'd put it down to that mainly, but ambient temperatures, fuel used, tire pressures, etc, can all have minor impacts as well.

I reckon you're a hard marker if you think that 22mpg is poor when you're averaging 80mph. At that speed you're pushing a lot of air out of the way remembering, of course, that aerodynamic drag increases in proportion to the square of the speed. So if you double your speed, you quadruple the drag.