I purchased this ML-320 new in 2000. At the time they came filled with regular motor oil. They indicated that the oil need not be changed for about 10,000 miles. Coming from the old school of 3000 mile oil changes, I did not buy into the plan and changed it at 5000 miles. Then at 10,000 they switched to synthetic Mobile 1 0W-40.

I changed it at the 10,000 mile interval since and now have 50,000 on it.

What do the experts say about this 10.000 interval with synthetic? How is engine ware etc. I'm planning on keeping this another 50 - 75 K (I hope)!

If there oil changes were not $130 a pop I'd just change it every 5000 miles.

Perhaps I could have someone other than a Mercedes dealer do every other change at a sensible price.

Thanks in advance for your input.

My story is similar to yours. My 2000 ML had regular oil that was changed at 5K, Then got synthetic at around 10K. But, since then the FSS has counted down to 2K after about 7500 miles traveled. Knowing that the dealer would change the oil anytime after FSS reached 2K, I had it changed. I don't think your interval would make any significant difference. I too plan to drive the ML for quite a while longer. I've never had any oil consumption so I'm not concerned about the oil changes and longevity. The rest of the vehicle's parts are another story!
PS. you can do your own oil changes for about $50. But, you'll need to develop a home-made oil funnel or get a top-sider oil extraction tool to avoid a big mess.

What type of other problems have you had?
I just ordered a new Mass Air Sensor as the CEL light came on and they told me the code indicated that the sensor is bad. They wanted $468.00 installed and I have a new one ordered for $165 plus shipping, It takes a screw driver and about 2 minutes to replace it.

So far we have been lucky with no other problems in 50K.

Wow, its hard to remember. I had a '98 that had many problems too (traded it for the '00) But here's the list as best as I can recall:
brake light switch
window switches
glove box door (twice)
defroster vent broken
Fuel filter upgrade
Brake jobs (first set at only 20K miles!) Switched to Mintex on second set and I'm still running them at 64K.
numerous squeeks
sunroof rattles
washer reservoir cracked
transmission conductor plug seal leak
coil failure
battery failure
power steering recall

OK, so most of it was covered under warranty, but I've had many toyota's. Several of them went over 100K without ever getting worked on! not even brakes! I'm out of full warranty now and it's scary.

My, you have had a lot of issues, the type of issues that lead one to think Mercedes really dropped the Quality mind set that they have had for years.

I wonder if the in Alabama is a factor or if it is just poor quality engineering.

I've owned 8 Mercedes over the years, usually purchased 3 - 4 years old and 6 of the 8 were Diesel Power.

I sold a beautiful 1993 300D and purchased this 2000 ML-320.

My wife drives the ML daily and I drive it on a rare occassions.

All the reading and investigation I have done seems to point at serious quality issues.

Wish I would have kept the 300D ! (5 cylinder turbo)

I do recall the window washer tank being replaced but I believe that is all until this CEL light indicating the Mass Air Flow sensor is faulty.

The MAS should be here today so I'll find out if that turns the light off after we drive it and let it auto adapt.

I'm getting to the point that I think one should buy a vehicle with the best and longest warranty as long as the safety ratings are desent.

Replacement parts on all vehicles are just unreasonable in my opinion for what you have to pay for the vehicle. It's like buying a house!

What State do you live in? We are in Northern Ohio South of Toledo.

As far a the quality issues, I don't think that the Alabama assembly plant has anything to do with the problems. Thru two ML's all of the problems have been part failures. If you bought your ML used, maybe many of the problems had been resolved. I'm west of St. Louis MO. Luckily, we have a good dealership here.
Oh yeah, how did you know you needed the MAS? And, where did you order it from?