Diff in MPG w/o EGR and ARV? - PeachParts Mercedes-Benz Forum

retmil46 · #1 10-13-2006, 02:02 AM

Over 3 full tanks now, this beast has averaged 31.5 MPG +/- 0.2 on each tank. Last fillup at the R mark was 14.5 gallons for 460 miles.

EGR and ARV are still stock (fully functional).

Would I see any noticeable difference in MPG if I gave them the BB treatment? Have seen this mentioned in various threads and the "recommended reading" links, just wondered if anyone has seen a MPG increase after doing this and a rough guesstimate of how much.

bgkast · #2 10-13-2006, 02:23 AM

Lucky Bugger! Try using a golf Tee to plug the lines and keep checking the mileage. If it does go down or you want to undo the modification a golf T is easier to remove than a BB.

Ara T. · #3 10-13-2006, 04:20 AM

I doubt you'd see much if any improvement. All i saw was a tiny tiny miniscule increase in power. These cars are so slow anyways it doesnt make much of a difference. Not to me anyway.

retmil46 · #4 10-13-2006, 11:34 AM

IMHO, this '87 300D Turbo/603 engine is anything but slow!

Perhaps one reason it's consistently knocking down 30+ MPG is the fact that the original owner had the trap oxidizer recall done sometime in the past. Looking underneath, I'd swear that's at least a 3" exhaust system.

Talking with robinSP, his father had an '87 300D. After he had a local machine shop take a spare oxidizer and remove the guts, then bolt the shell in place, he claims it could achieve 38 MPG highway. After what I've seen with mine, I'd say that's definitely within the realm of possibility.

Everything seems to be adjusted prety well on this beast. Only get some light smoke on cold idle startup, after that none that I can detect while driving. Idle may be set a little lean, does have a good amount of clatter, but once warmed up and off idle doesn't sound any different than a gas engine.

Only been able to produce a black cloud out the exhaust once, on the first Italian tuneup I gave it (blacklunged an '06 Mustang riding my bumper

). Since then, nothing I've been able to see in the mirrors.

Sounds like in my case, the BB treatment is under the category of "nice idea to try when I have the time".