While using antisieze is generally good practice, the plugs aren't siezing in the glowplug threads. They develop carbon at the heating element end and sieze there.

I don't know if reaming the glowplug holes into the prechamber would help. Probably couldn't hurt but I truly don't want to R&R them unless one goes bad. I had two bad 30000 miles ago and they all came out without any issues.

Diesel Kleen in the summer, Diesel Fuel Supplement when it's under 32*f. Always.

our average temp is around 50 degrees right now. ive been using the white bottle. is it warm enough that i should be using the silver bottled stuff? or should i be using what i am with the weather slowy but constantly getting colder?

I don't know about that. At 55K, I had 3 stuck plugs. 2 came out and 1 broke. I tried to drill it out and almost had the head FUBARed when it came out. Took it to a machine shop and they fixed it. To do that, they got the prechambers out and other than a little deposit on the prechambers in the combustion area, they were pretty clean. No carbon. This time, I checked it and also was pretty clean. So, I don't believe it is the carbon that is screwing it up. At least not in my car. Checked the prechambers and all.

That's encouraging to hear. You're the first one I've heard about with issues on the threads. The posts I've seen have been with folks getting the threads clear and the plug just rotating.

Yeah, when I replaced mine they were all reinstalled with antisieze. What makes you feel that you have to replace the antisieze every couple of years? I don't believe that they were installed from the factory with any so shouldn't you be good until one burns out?

I think of it as preventative maintenance. I don't believe the world revolves around MB. Just because they didn't do it from the factory doesn't mean it isn't a good idea. Lots of people have stuck spark plugs because they are told that they don't need to change it for 100K. Their plugs are thicker than ours so it isn't as bad. More elbow grease. For us, plugs could break. I believe sokoloff had one break off on him too. I suppose my thing is that I tend to do "Italian Tune Ups" several times a day so carbon doesn't get to build up.

I use 6 oz. of Power Service for most fillups (about 15 gallons). Both the SD and the SDL seem to stay very clean and run well over the course of the past 18 months or so. Seems to have an overall long term benefit.

Can't vouch for the mileage increase. Both vehicles are currently averaging in the 29's. This is quite good for the SD.

I go along with Mercedes stance that no additives are needed on a routine basis. All it does is add to your cost of operation IMO, but it's like a lot of other things. If it makes you feel better and you think it works, go for it.

Len
'83 240D 345,000 miles original owner/no additives/still running great