This may be unbelievable but true.
My ML320 with 90,000 miles used a quart about every 1,000 miles. It also ran rough. I paid my dealer $75 to computer read the engine. He suggested $250 for a new EGR Valve installed. I wanted to check this site 1st. I was told to check the EGR Tube. It turns out it was totally plugged. I cleaned it. I also added Gummout Emission control cleaner to the gas. I run Mystery oil in each tank currently. My ML320 has used no oil for the last 3,000 miles. I am dumb founded.
The origional owner told me it used a quart every 1,000-1500 miles since NEW.
Go figure.

__________________
Steve Danville
what i did myself.
CPS
rear shocks
MAS x 3.
SparkPlugs (twice)
Fuel pump & Filter
Window switch
replaced both failed horns with Honda horns.
Cleaned ERG Tube
Oil changes
Oil consumption Fix
Brake Pads
A/C Recharge
Anti-Freeze change X 2.
Front Shocks. Monroe. $90
Mercedes Warrenty Work:
Harmonic balancer,power steering clamp. Cat converters.Drive Shaft Bearing.s
Replaced Outer Lower Tie Rods and front lower ball joints at 156,000 miles