[OmahaDZL]

As some of you know, I recently picked up a 2011 X5d with 115k miles in pretty much immaculate shape. Previous owner had it since new and had an extended warranty on it, which means everything was done at the dealership. Engine bay looks pretty much immaculate....

Now for the reason for the post.... I have driven a little over half a tank and Im on pace for 500 miles at empty... of those 250 miles, probably around 175 to 200 has been interstate on cruise control and the rest has NOT been at WOT.

EPA is listing this thing at 26 mpg highway but it doesnt look like Im going to get to that...in my 335d, it always seemed like I was above hwy rating...

Any feedback as to if this is normal milage? They JUST replaced the thermostat before I bought it, so thats not it. its possible I have some rolling resistance with wheel bearings but other than that, I dont see any issues...Ive got zero codes....so Im just trying to baseline expectations....but frankly I expected better numbers out of the milage.

All in all, I am VERY happy with my purchase.... very very happy....just trying to make my x5d the best x5d it can be.

[robnitro]

Were you resetting the mpg display and seeing what you get on the highway for a constant stretch?
If so what did it say and at what speed were you doing around?

I do 30 at 60-65, but 75 will go down to 28-29. That's from the mpg reset and watched while driving on highway. If regen kicks in, it drops but I haven't watched how much.

The rest of my driving is nyc area traffic which is a lot of stop lights idling which kills mpg.

Mixed driving on a tank is hard to tell.

[temporaptor]

I got 26mpg once on the way home from Las Vegas one time. My weekly average floats between 21-22 mpg. I'm guessing the 315/35R20's don't help with mpg numbers. My worst tank mpg was 18mpg.

[OmahaDZL]

No I wasnt resetting but I was cruising at a little over the speed limit so im sure I wasnt getting the best I could have gotten... Alright well its more in line with what its supposed to be...I was thinking i would get around the 30 area on the interstate, but it doesnt look like thats going to happen..

[BB_cuda]

If not reset, the regens are mixed in there. Do a reset just after you know you have finished a refen. My 2 cents

[335dsleeper]

We can get 30-31mpg with highway driving if we do the speed limit. We typically average 26-28mpg with roughly 80-85% being highway driving. City driving and idling in the Starbucks drive-through really puts a dent in our fuel economy.

[robnitro]

I reset as I go on a trip to see the baseline, because mixed driving and regens will throw in too many variables. For fill tank mpg, I use the idrive trip tool and compare to gallons filled/miles driven. The car is 1% optimistic.

Also if you do jbd or other plug in chip, your mpg display will be off.

[fsd350]

We get about 26-28 on the wife's X5d highway only at 75. 73 corrected. She gets 24ish mixed. 20 inch wheels. We live in a somewhat rural area. Power service extreme diesel fuel seemed to help with mpg a bit.

[OmahaDZL]

I never use the electronic version as real mpg

I always fill up to the first click of the pump....and then do the straight calculations after the next fill. Granted Im doing some assumptions based on what the computer says at the moment, but the fuel tank gauge seems to be backing it up.... We will see once I fill up again what the numbers turn out to be....

Ill leave the JBD off for the first few tanks just to get a good baseline...

[robnitro]

Yeah jbd will make the computer read optimistic. Ecu calculates how much fuel by the calibration of pressure and duration. Jbd changes pressure without the ecu knowing by fooling the rail pressure sensor.

[captpilly]

I have a 2011 X5D - T-Stat and all the normal things have been replaced. I drive it pretty hard - 80 to 90 mph and get a around 24-25. Non-hwy miles are 18-22

A few times when I didn't drive it so hard, and used cruise control around the speed limit, I got 28.