Diesel hypermileing

[GoVols!]

Relocated to the DC area this weekend. Drove the X fully loaded from Omaha. Filled up in Iowa City, IA and drove to Wheeling, WV on one tank. Cruise was set 5 above the limit all the way. Made 5 or 6 stops or so for food, bathroom breaks, and an overnight.

665 miles
avg speed - 68.something
30.5 mpg on the OBC 30 on the dot by my calculations.

Still had 30 or so miles till empty but didnt want to push it not knowing the area. Hoped to get 700 and send a picture to BMW. Probably could have done it if I had gone a little slower. The 20+ mph tailwind helped.

Anyone ever beat that?

[kakalika]

WOW!! that is really excellent economy for a big heavy vehicle like the X. I understand the economy gets even better with removal of the DPF and reprogramming the ECU.

[JCL]

Don't understand why anyone would remove the diesel particulate filter. Spewing carcinogens and ugly black soot?

[Diesel Guy]

Take off the DPF and you won't be able to see out the driveway when you back up......the DPF is so good at removing soot, it allows the engineers to focus on in-cylinder performance and fuel economy. The DPF doesn't effect fuel economy per se...... And the tuners have a better chance of screwing up peak cylinder pressures and causing early engine failures than it's worth.

IMHO...enjoy what you have, and put your cash into speaker upgrades......or better yet.....buy gold!

[diesaroo]

Removing the DPF and other emissions hardware (EGR) might not be "environmentally friendly" or legal, but it does simplify things and theoretically will reduce the amount of possible engine failure modes down the line.

I think fuel economy would likely improve as well with the removal of EGR & DPF since the intake charge would be cooler (EGR) and there would be fewer flow losses due to having no DPF.

Not to mention the added benefit of having clean intake valves instead of the cruddy mess caused by EGR.

[deutsch100]

Originally Posted by JCL

Don't understand why anyone would remove the diesel particulate filter. Spewing carcinogens and ugly black soot?

1000% One of the things that makes me LOVE my 35d the most is NO sooty, black & disgusting exhaust. I am such a diesel snob now! When some early 80's Mercedes 300D or some old Volvo diesel wagon is in front of me...and I can literally see the greasy diesel droplets hitting my windscreen, it pisses me off. I honk at them, pass them, hold my nose and make a face at them. Seriously, those cars should not be allowed on the road...and I owned a 1983 300D and 1992 300D. I loved them, but they were so sooty and gross!!!

[Jeg Norge]

so if i want to get good mpg, i must drive 600 miles straight. ok next time i'm going to the grocery store i will take a loooooongggg detour LOL

[kakalika]

It seems that in Europe, there are companies specializing in removing DPF's from diesel cars and removing all traces of DPF software from the ECU. They report significant increases in fuel economy and performance. The kit consists of a pipe that replaces the DPF and the software. And with the DPF removed, you can use 100% biodiesel as well. I read somewhere on a Chevy Duramax forum that fuel economy dropped from 20mpg to 15 mpg when they put a DPF on the Duramax diesel.

Ecotune - economy tuning and performance tuning for cars and commercial vehicles, ecu remap, custom mapping, economy improvement - Ecotune UK Ltd

The kit is expensive though, but it is cheaper than replacing the DPF when it needs replacement. It claims 5 - 10 mpg improvement, which sounds a little far fetched to me. I don't know, but it sounds interesting to me.

[Viperfreak2]

My mother loved driving her 1980 Audi 5000s Diesel. Whenever anyone would tailgate her *(67 horsepower!), she would floor it! They backed off real fast, or went around...

[kakalika]

Here is a video of a 535d without the DPF

YouTube - 535d 3" stainless exhaust turbo back No CAT or DPF