Engine Oil Switch

Can't find proper grade oil for winter - only 20-50 with CG4 designation for my '91 350SDL with 280K miles. Saw someone on an earlier oil post using Delvac1 5-40 but dealer service will not put in synthetic oil for me. (Same dealer's been servicing since new). With price of fuel in this area < $2.01/gal, looking for every edge plus thinner oil. I can't find any mineral oil based 10-40. Any suggestions? Does it really hurt to change to synthetic?

[mpnye]

With that kinda miles . . . STAY with 20w50 Petroleum . . .

QUIT while you're AHEAD ! ! !

[Wasuchi]

If you are looking for a mileage increase...... synthetic oil doesn't make a noticeable difference. I would stick with whatever you're using.

[gsxr]

Your dealer is an idiot. I can't believe all the fairy tales out there. Synthetic is about the best thing you can do for your engine, believe me. And Delvac-1 is about the best diesel synthetic oil on the market today. There is NO problem switching at high mileage. I switched all three of mine at time of purchase, at 190k, 228k, and 202k respectively and have seen nothing but fantastic results.

It will not provide a large increase in MPG, but should give you maybe 0.5-1.0mpg better after a few thousand miles. It also helps with cold starts (particularly in sub-freezing weather), can quiet noisy lifters in your 603 engine, lowers oil temps, and will clean out the sludge & deposits from years of using dino oil. You can extend the drain intervals as well, to at least 7500-10,000 miles unless you do all city driving. It can reduce oil consumption as it frees the rings up, if they were sticky to begin with. It can take 5k-10k miles on the synthetic to see the full benefits, although some notice a difference in a few hundred miles. YMMV, of course.

Synthetic won't cause leaks, won't ruin your engine, won't make your wife leave you, or your computer crash. Don't believe everything you read on the Internet. Please only use Delvac-1, or Mobil-1 15W-50 or 0W-40. All the xW-30 weights are not aproved by MB for use in their engines, they are too thin! Amsoil and RedLine also make excellent diesel oils but they ususally cost more. DO NOT use Castrol Syntec and I'd also avoid Shell Rotella "synthetic", as both are hydrocracked dino oils with lots of viscosity improvers & additives tossed in to make it act like a synthetic. Don't be fooled, the Mobil/Amsoil/RedLine products are the real deal.

Try it out & report back, I bet you'll like the results! Oh, btw, I use Delvac-1 in my diesel fleet.


Regards,

[mpnye]

Originally posted by gsxr
Your dealer is an idiot. I can't believe all the fairy tales out there. Synthetic is about the best thing you can do for your engine, believe me. And Delvac-1 is about the best diesel synthetic oil on the market today. There is NO problem switching at high mileage. I switched all three of mine at time of purchase, at 190k, 228k, and 202k respectively and have seen nothing but fantastic results.

It will not provide a large increase in MPG, but should give you maybe 0.5-1.0mpg better after a few thousand miles. It also helps with cold starts (particularly in sub-freezing weather), can quiet noisy lifters in your 603 engine, lowers oil temps, and will clean out the sludge & deposits from years of using dino oil. You can extend the drain intervals as well, to at least 7500-10,000 miles unless you do all city driving. It can reduce oil consumption as it frees the rings up, if they were sticky to begin with. It can take 5k-10k miles on the synthetic to see the full benefits, although some notice a difference in a few hundred miles. YMMV, of course.

Synthetic won't cause leaks, won't ruin your engine, won't make your wife leave you, or your computer crash. Don't believe everything you read on the Internet. Please only use Delvac-1, or Mobil-1 15W-50 or 0W-40. All the xW-30 weights are not aproved by MB for use in their engines, they are too thin! Amsoil and RedLine also make excellent diesel oils but they ususally cost more. DO NOT use Castrol Syntec and I'd also avoid Shell Rotella "synthetic", as both are hydrocracked dino oils with lots of viscosity improvers & additives tossed in to make it act like a synthetic. Don't be fooled, the Mobil/Amsoil/RedLine products are the real deal.

Try it out & report back, I bet you'll like the results! Oh, btw, I use Delvac-1 in my diesel fleet.


Regards,

Hmmmmmmmmm . . . OK

OPINION and LIABILITY are two TOTALLY different things.

I would NEVER make such a BROAD statement WITHOUT SPECIFIC INFORMATION regarding the ENGINE'S CONDITION. I've sold SYNTHETIC lubricants at my shop for years, and have learned a few HARD lessons in the process.

I've seen HIGH mileage engines convert to SYNTHETICS with GOOD results and some NOT SO GOOD . . .

[gsxr]

So what were the "no so good" results, and how was it proved to be the result of using synthetic oil? If your engine is shot already it's hard to blame a failure on the oil used... the original poster said nothing about the engine running poorly, so we're assuming he has a great-running OM603 like most of them are! I have yet to hear one valid story where switching to a good synthetic (not Castrol or Rotella) actually CAUSED a problem.


Best regards,

[mpnye]

Originally posted by gsxr
So what were the "no so good" results, and how was it proved to be the result of using synthetic oil? If your engine is shot already it's hard to blame a failure on the oil used... the original poster said nothing about the engine running poorly, so we're assuming he has a great-running OM603 like most of them are! I have yet to hear one valid story where switching to a good synthetic (not Castrol or Rotella) actually CAUSED a problem.


Best regards,

Well . . . for instance . . . When a HIGH MILEAGE engine pumps through a quart of Synthetic in 200 miles and runs out of oil 1200 miles after adding it . . . and by the way . . . SYNTHETIC DOESN'T SMOKE like petroleum, so it's pretty much UNDETECTABLE and MOST customers who claim that they check their oil every time they fill up, miss this as some have AUX. tanks which stretch a fill up to 1200-1500 miles . . .

[gsxr]

Well, I may be out of line, but IMO any engine that burns up a quart in 200 miles is hardly a candidate for a synthetic switch! Sounds like time for a rebuild to me. What was the consumption of this engine with dino oil? What weight dino was used before, and what weight synthetic was used?

Note that I didn't make a blanket statement to just use any synthetic you feel like, I said exactly what brands & weights to use, which also happen to be what Mercedes-Benz specifies in writing for their engines. FWIW, Mercedes now *REQUIRES* the use of synthetics on all their engines, and the warranty is void if synthetic is not used. I can dig up some URL's with more info if you'd like...


Best regards,

[mpnye]

Originally posted by gsxr
Well, I may be out of line, but IMO any engine that burns up a quart in 200 miles is hardly a candidate for a synthetic switch! Sounds like time for a rebuild to me. What was the consumption of this engine with dino oil? What weight dino was used before, and what weight synthetic was used?

Note that I didn't make a blanket statement to just use any synthetic you feel like, I said exactly what brands & weights to use, which also happen to be what Mercedes-Benz specifies in writing for their engines. FWIW, Mercedes now *REQUIRES* the use of synthetics on all their engines, and the warranty is void if synthetic is not used. I can dig up some URL's with more info if you'd like...


Best regards,

The engine had TYPICAL OIL CONSUMPTION prior to installing SYNTHETIC OIL . . .

A combination of CYLINDER OUT OF ROUND - TAPER - EXCESSIVE PISTON TO WALL CLEARANCE - RING WEAR on HIGH MILEAGE engines provide a PATH OF LEAST RESISTANCE for SUPER SLICK SYNTHETIC OILS . . .

[gsxr]

Again, what is "typical consumption"? Most manufacturers consider anything above 600mi/qt to be "normal". I consider 3k-5k miles per quart to be "normal" for my cars. I have heard of cars with 1-1.5k per quart actually using LESS oil after switching to synthetic, as the oil control rings free up inside the piston grooves. It can take a while but really can happen.

The engine you describe has massive MECHANICAL problems that simply cannot be blamed on sythetic oil, IMO. I'd be willing to bet a can of Diesel Purge that the engine described was NOT a Mercedes diesel, though. If so, what make/year/model was it? This would be extremely rare in Mercedes land, like way less than 1% of the time. The other 99% experience positive results. Just my $0.02...




Regards,

[Elliott Fager]

I am trying to find a good 20-50w rated for diesels. Any thoughts

[mpnye]

Originally posted by Elliott Fager
I am trying to find a good 20-50w rated for diesels. Any thoughts

20w50 . . . WHAT ? ? ?

as I stated in my original post 1991 350sdl with 282,000 miles, original owner, dealer serviced. No major problems until last month when tranny went and steering box needed replacement within three weeks.
Really agonized over fixing it, but obviously decided to keep it.
Engine runs fine. Burns a quart about every 1500 miles. Mostly highway. Will probably need major work soon, but am hoping for it to last until new diesels are out next year.
So, judging by the posts, even Delvac 1 is risky.
So, what petroleum product do I use if I want a 10-40 with a CG-4 designation. The dealer says it uses 10-40 when I get an oil change. My assumption is that it doesn't have the CG-4 or any other diesel designation (CJ?) So, if I use regular, old 10-40 Pennzoil until the summer when I can switch to a 20-50 with the CG4 desisgnation, am I good to go?

[gsxr]

Elliot, I don't know of any 20W-50 oils that are diesel rated (CF/CG/CH/CI). Why do you want 20W-50 when all the good dino diesel oils are 15W-40 (Delo 400, Delvac 1300)?

mpnye - You first. :p (And I see you didn't answer any of the other questions...)

[Elliott Fager]

20w-50w oil rated for diesels is what I am interested in. I have a '81 300sd. Sorry, forgot to include the word "oil" in my previous post