MB Enthusiast

I am thinking of changing from regular oil to synthetic.

What viscosity should I use and what is the proper procedure for the conversion

1997 E 320 159,000 miles

diffuzi0n

i am not 100% but i think that the oil that you should have been using was synthetic oil to begin with. I and, I think most of us here, use here mobil 1 10w30.

MB Enthusiast

I checked the Mobil 1 site and they tell me for my area and my car 15W50 or 0W40

Anyone else have input

E320Star

Well, u have 158k miles on the car. Why synthetic now !!! It has been running seems like all along. It is toooo late now bro. U shoudl have used synthetic long time ago to xtend the lif eof the engine.

OceanView

Not sure if it is necessarily too late now but I use Mobile 1 15W - 50 and it has been fine.

If you do start using synthetic, know that there is a possibility of oil leaks around the seals and gaskets.

E-Klasse

Switch to AMSOil and use the same weight as you were with hydrocarbon oil. Even with the amount of miles you have you can take advantage of not changing the oil as often now with the synthetic. If you go to a 0W-40 now you could start to have oil leaks because it will find gaps and cracks that your conventional oil was too thick to get through.

MB Enthusiast

I bought the car with 98,000 miles on it and there was only one owner.

The first owner had the dealer do all service and the car was immaculate when I bought it.
I have two questions for the forum first is it standard that the dealer would use synthetic?
Second if I use 15W50 synthetic now will I increaser a leak problem that I already have?
It is not bad and does not cause me to add oil between changes.

MB Enthusiast

I bought the car with 98,000 miles on it and there was only one owner.

The first owner had the dealer do all service and the car was immaculate when I bought it.
I have two questions for the forum first is it standard that the dealer would use synthetic?
Second if I use 15W50 synthetic now will I increaser a leak problem that I already have?
It is not bad and does not cause me to add oil between changes.

Messerchmidt

you can use synth, but it may leak. toss in a bottle of lucas synth heavy oil stabalizetr, that should fix it.

if your mechanic changes the seals on the engine, you should not have a problem.

jimmydagreek

Well, I bought '97 E420 with 99k miles on it and my MB mechanic made me use synthetic, I had no choice. He said regardless of the miles it's never too late. Synthetic oil helps lube your engine better than regular oil and helps keep it cleaner by avoiding build up on your valves and lifters, which will cause ticking and the possibility of them getting stuck down the road. Believe me, it happened to me and I had to replace all of the lifters, it's not cheap. My mechanic used Mobil1 10W30 for high mileage vehicles formula and I put 40k miles on it before I sold it and the engine purred...

E320Star

Synthetic is only required on MB starting with model year 1998 Thru current. It is not required on 1997 or older. It will be a waste of money I beleive.

JLLG

I bought a 97 E320 with 105k and switched to Mobil 1 0w40 right away. I change on 10k intervals. I have the infamous head gasket leak but in 10k, I lose no more than 1 liter.

ccmbduong

I have a '96 E320. I switched to Mobil 1 after 40K miles. The reason I made the switch is to extend the oil change interval from 3000 miles (regular oil) to 10K (Mobil 1). If you change oil every 3000 miles then you don't need to change to Mobil 1. Never have any leakage after the oil switch. I use Mobil1 15-50 from Walmart or 5-30 from Costco.

Peteski

Just to confuse the issue, my M-B service guy stated that I was NOT to use synthetic in my '97 E420! And he stated further that this was M-B's call. Of course, on the '00 I use nothing but synthetic.

MB Enthusiast

Is there anyone else that feels this way?

Tell me more

JLLG

If you are referring the MB service guy stating no to synthetic on the '97, I would have to say that they just want you in for service more often. When I switched to synthetic on my '97 E320, I did this at the dealer by my request. I would imagine if there was an issue with switching, they would have told me. I like using synthetic because of the extended change intervals.

Peteski

I just thought of something: I'll bet it was because that '97 4.2L was an "old" engine, while the '97 3.2's were the "new" type. I think that must be it, because he specifically told me that M-B had stated that regular oil was to be used in that car - and they had serviced it since it was brand new. And if he was wrong about this it wasn't because he thought they'd get me for more service visits, because I don't put that many miles on my cars, so I tend to get the ol & filter changed every six months and mileage isn't really a factor.

E320Star

I agree that in 97 and older, is to use what is recommended by the manual. All 98 and newer must use synth.

JLLG

Correct me if I am wrong but I think you meant that a '98 E320 has the newer V6 motor. A '97 E320 still has the 104.995 inline 6 motor.

Also, I really think either oil type will adequately protect your engine if changed within the proper interval. I just personally chose to go to sythetic.