I was at the local Napa store the other day to purchase an oil filter for my 1999 e300 and the sales person suggested that I should be adding a quart of two cycle engine oil to my fuel tank every time I fill up as an injection pump lubricant because the low sulfur diesel no longer provides enough lubrication!
I'm wondering if any of you guys here add oil to your diesel , or if it is really necessary?

I do especially for the 24V Cummins after reading all of the scuttlebutt there. Have also seen pics of injectors run with 2-stroke and they looked normal. It may not be critical for these IP but it won't hurt.

One oz per gallon of fuel is one touted strategy but we do not have test labs and can't really know for sure. Wally world has the cheapest. I scrounged ~ 15 quart oil bottles from Autozoo and transfer a gallon to the empty bottles. They are stored in the trunk & truck box.

I'll pick up 2-3 gallons at a time because I don't like to shop at Walmart. This is enough to last a while.

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85SD 240K & stopped counting painted, putting bac together. 84SD 180,000. sold to a neighbor and member here but I forget his handle. The 84 is much improved from when I had it. 85TD beginning to repair to DD status. Lots of stuff to do.

I use Opti-lube summer formula. Yes, it is a good idea to use something to help lube the injectors.

FWIW my oil analysis tech, who for the most part takes an "anti-additive" approach to things, says this is the one area where it really makes sense to add some lubrication.

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14 E250 Bluetec 4Matic "Sinclair", Palladium Silver on Black, 154k miles
06 E320 CDI "Rutherford", Black on Tan, 172k mi, Stage 1 tune, tuned TCU
91 300D "Otis", Smoke Silver on Tan, 142k mi, wastegate conversion, ALDA delete

19 Honda CR-V EX 61k mi
Fourteen other MB's owned and sold
1961 Very Tolerant Wife

2-cycle oil for me as well. If there's anyone who argues against extra fuel system lubrication on a diesel then run the other way.

-Rog

Cheap insurance....

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Current Stable

• 380SL (diesel)
• Corvette C5
• Manx
• Baja Bug
• F350 Powerstroke
• Auburn Boattail Speedster replica

I'm just happy that no one is touting ATF. . ( That in no way was designed to be burnt in an engine . )

We have an 04 Sterling truck 30,000 GVW with a OM906 that has 400,000+ miles running on standard on road fuel. Other than filters and pump to injector lines due to cracking, the fuel system is untouched and it runs just fine.

Opti lube XPD is what im going to use.

The Cummins guys found that it quieted down their engines, but they didn't really care for that attribute.

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1998 Ford Escort ZX2 5 speed - 279,000 miles My Daily

1992 Mercedes 300D 2.5 202,000 - Pure junk
2000 Mercedes E320 Black - 136,000 miles - Needs repair

Don't forget to grease the screw and threads on the spring compressor.

Another option is biodiesel. 5% will add plenty of lubricity, and a gallon of biodiesel will cost less than a quart of two stroke oil. If Wisconsin has a biodiesel mandate, you're probably in the clear. Oregon has 5% mandate and I don't worry about it at all.

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617 swapped Toyota Pickup, 22-24 MPG, 50k miles on swap

8 Oz. in a 13 gallon tank.

Also Redline Diesel Fuel Catalyst

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'84 300SD sold
124.128

absolutely true.. low sulfur fuel is horrible for these cars. two stroke oil won't hurt anything btw. i woulddn't be worried and i'd run it through my om606s.

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Only diesels in this driveway.
2005 E320 CDI 243k Black/Black
2008 Chevy 3500HD Duramax 340k
2004 Chevy 2500HD Duramax 220k

Fill the fuel filter when changing, with ATF.

Add ATF (a few oz.) every few fuel fillups.

ATF has 'super' high content of detergent, this is what works, , ,

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"I applaud your elaborate system of denial"

ATF isn't designed to be burnt and will have a high ash content leading to carbonized combustion chambers / injector nozzles. Granted, the amount you are using isn't like the " I'll burn anything " crowd.

Oh, the irony. . .

My friend who has worked at Bosch since 1968 says, "Use any top tier diesel fuel and you should be fine." He says Bosch tests diesel fuel from different stations and there is a difference....stick with top tier such as Philips, Exxon/Mobil, Conoco and Sunoco.

I think the only MB approved additive is Biopor for Algae/microbial control. He said Bosch and MB do not recommend adding anything else to the tank.

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-- Chris

'95 E300, 216k miles, Silver Surfer
'05 E320 CDI, 138k miles
'07 S550 4matic, 69k miles

Gone but not forgotten:

'76 300D, 350k miles?, SOLD in 1995
'75 240D, 300k miles, SOLD in 1991

Opti-lube is bine however it is more concentrated and easy to over-dose which just costs more. Also, 2-stroke is more readily available.

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85SD 240K & stopped counting painted, putting bac together. 84SD 180,000. sold to a neighbor and member here but I forget his handle. The 84 is much improved from when I had it. 85TD beginning to repair to DD status. Lots of stuff to do.

I would be very surprised if Mercedes/Bosch bothered to go back and test old injection systems with new low-sulfur fuels in any meaningful way. "Seems to still run fine" isn't enough for me personally. There's no way they've tested them for thousands of hours to measure longevity with less lubrication.

Injection pumps don't last forever, despite what many say. On this board we're starting to see more and more people with issues that were only resolved by servicing injection pump parts. Is it the new fuels or just age? Hard to say, but I'd like to give mine the best odds I can.

-Rog