A few more things about Mobil One.. besides the lowered pour-point of the oil another great advantage is it's high temperature tolerance. It will continue to lubricate well without fractioning (distilation) at hot points like exhaust valve stems and wrist pins. Low quality oils will fail at these points leaving deposits that adhere to the metal. Prior to owning a Benz I had a fuel-injected Volvo.. I went 20,000 miles on a single change of Mobil One.. the oil was still pink and clear at that point. The synthetic makeup of the oil does not require the complicated additive structure to make it a good lubricant that petrol oil does. These additives are degraded by chemical assult from combustion byproducts. Diesel truck fleets regularly go 100,000 miles on a single change of Mobil One (with aux micron filters). Gasoline fired engines with precise fuel injection systems can to farther on a change than carburated engines due to less chemical assult from un-burned hydrocarbon residue. So.. there are a lot of variables.

Thanks for all the input on Mobil 1. I think I will use to 10W-30 in my 99 E320. The dealers here in southern Arizona still insist that they use 10W-50 in all the cars because of the heat here. But they don't use synthetics. (Can you imagine what a dealer would charge for 9 quarts of Mobil 1? I can but it and take it to them for about the same as they charge for bulk conventional oil.) The dealers also seem to have this throwback mentality that dates back to the days of single weight oils (and I was there :-) that says you have to use 50-weight for hot weather. Both Mobil and MBNA assure me that a 5W-30 or 10W-30 will be good for any weather I find in most of the US. Mobil, in fact, says that the 10W-30 is more able to handle high temperatures than any conventional 10W40.

Trying to get info about what oils to use has been more difficult than I expected.

Chris, olc - I beg to differ with in reguards to the "Star" article.
Second para. "Only engine oils(including SYNTHETIC or RECYCLED OILS)with any of the following classification grades or combinations thereof are approved:. The ACEA and API grades are then given.
The next para. tells which viscosity grade to select, based on the temp. range you expect to be driving in. Please see the chart, at the bottom of the page.
Both diesel and gasoline engines are covered by this article.
I don't believe any auto builder in the world would be brand specific, with the exception of Mercedes (read AMG) and GM (Corvette latest edition), both of which recommend Mobil 1.
Please don't take this as a flame, but the all the info you need to select your oil is in this article. You must still choose a brand, and formal testing that I was involved with indicated that Mobil 1 was better then about any thing else.
Note: Mobil 1 recommends at least 6000 miles be put on the engine with coventional oils before you start using it, or at least they did.
I hope this helps.

------------------
98 SLK
MBCA
Greater Washington Section

Being a new owner and not having received my first Star, I don't have access to this chart. My local dealer doesn't have the Star around. Could you possibly give a brief summary of what they recommend? I intend to use the apporopriate weight of Mobil 1.

For a specific Mobil 1 weight...if I were putting my car on synthetics I would likely switch to 15-50 Mobil 1 fully synthetic. Most parts stores sell it for about four bucks a quart and twenty three bucks a case. I probably would put the 500E on synthetics but for its six figure age. It actually has a cleaner valvetrain than most cars with 30K miles but... It has done so well on 3K mile 15w-40 QS changes so I may stick with what works. For your 99 E320, give it 10 or 15 thousand miles to "break in" on conventionals, then go synthetic.

Lee

PS Your dealership should be able to show you the same chart they had printed in the Star. I've seen that same chart before in various MB literature. Odds are he should have some of that on hand.

The latest "factory approved service products" list can be ordered from your dealer - part # S-0473-98L. They do not list approved oil by manufacturer but rather by viscosity/temperature charts. You can probably get someone at the dealer to make a copy of the sheet for you. Since you are obviously taking the oil change very seriously, do you plan on following the flexible service feature for determining oil changes or are you going to change your oil on your own schedule? What are your thoughts on flexible service as an owner. Was the system fully explained at delivery?

My only comment regarding the above few posts relates to "running 10,000 to 15,000 miles then switching to Mobil One".. Thats what I did in 78 and it was recomended.. However, recent information buried deep in Mobil's technical stuff states several times that the precision machining techniques now used by major engine manufacturers renders little benefit from that method. They cite a few autos that come from the factory with Mobil One already installed in new cars.. I THINK Corvette and/or Ferrari were on that list. A full browse of Mobil One's website on the product might find it. All that said, I would still run several thousand miles on conventional oil, get a feel for consumption rates, let wear patterns set in a bit, then switch. Mobil has many pages on the synthetic products. Also, Mobil's Delvac One is the synthetic they sell to trucking fleets. It has the same benefit of the synthetic but formulated to better suspend soot generated by diesels. It is a little more expensive than the regular Mobil One and probably not worth the investment considering our frequent change rates compared to trucking firms. Also, I believe it only comes in the 15W50 grade.. could be wrong on that though. But the purist who wants the best could likely do very well to install one of those micron-level filters, (available as after-market fitting for Benz) use Delvac One , and extent change rates considerably. If you go searching for Delvac One (available at some truck stops and any Mobil distributor) don't confuse it with just plane Delvac.. that is a conventional oil.. look for Delvac ONE.

[This message has been edited by Dennis (edited 05-27-99).]