Quaker State HDX 15W40 Oil

[tec01]

I purchased a 1990 500SL just over a year ago with 160,000 km on it and did an oil change at that time with Quaker State HDX 15W40 as that is the oil the previous MB dealer had used for several changes. The oil performed well as I went 10,000 km with the oil not even going down on the stick. I am ready for another change but after checking the Quaker State web site it looks like HDX is designed for diesel engines. Does anyone else use this brand in MB gasoline engines? Am I at risk of engine damage? Any information would be appreciated. Thanks

Tom Coffey

[tecqboy]

If you do a search on this forum, you'll find endless discussions on oil. Ultimately, you must make your own "informed" choice. I think 15W is a tad heavy, even for an older engine. I used to use 15W until I took the oil filter cartridge out on a 40 degree day and found the oil as thick as mud. I have switched to 5W40 synthetic blend and I've noticed that the engine doesn't "rattle" at start up nearly as long as it did with the heavier weight oil. That is, the oil pressure comes up faster with the lighter oil on a cold engine. My Sl300 has 100K miles and doesn't use any oil between 4000 mile changes.

[rickjordan]

Just look at your owner's manual and use the weight they recommend for the anticipated temps.
My inlaws recently bought a '92 190E 2.6, and their owner's manual says to use 15W-40 or 10W-40 for colder temps. I have yet to see ANY owner's manual from any car manufacture that list weights based the type of oil being used (conventional/synthetic) You could simply ask the local dealer what they use come winter and keep using the 15W-40 for the warmer temps. Quakerstate isn't the only 15W-40 out there. There is Mobil Delvac 1300, Chevron Delo 400 and Shell Rotella. I don't know what is available up your way. BTW, no you're not husting anything by using "diesel rated" oil. That oil is also gas rated. Look at the lettering, it should say "SJ" "SH" etc. The "S" is for spark engines. Any "C" lettering is for compression enignes (diesels).