I have a 81 300 SD that probably has bad rings. SUcks i know. But as she's still strong I'm ecking as much out of her as possible while I save $$$ to buy another MB. I've been bitten by the bug.

Question being: I normally use Castrol 20w50. After reading everything on this board about oils, I switched to C rated 15w40, however, since this is thinner oil, my extremely high consumption rate (approx. 1 qt every 200-250 miles) was even higher (1 qt every 100 miles). Needless to say, I just switched back, did the oil change yesturday, already seems better, marginally, too soon to tell though.

The guy in the autoshop talked with me about straight 30w oil, thicker than 20w50. I live in the Santa Cruz Mountains, the temp is into the low 30'sF now, and last week we got some 23 degrees, although that's at night and days are still in the 50's and higher.

What do folks think about this 30w oil for this particular application?

Might it help seal the rings a little better?

ALso, he said I could try this product called restore which has tiny copper filings in it, which may melt on the cylinders and create better seal witht he rings. Anyone know about this stuff? Snake oil? Makes me nervous to stick metal purposefully in the engine oil!