In buying a new 98 Diesel, I was amazed at this new oil changing interval Benz is recommending. Being a mechanic from way back, it was hard to believe that I could actually go up to 20K between changes. However, I looked hard and long at it, and after talking to the head tech at Benz Canada, here are a few things that just may change this old 5,000 km's (3,000 mile for you yanks) attitude.

The new car holds 8 Litres of oil!, double what some of my old diesels held.

The cylinders are silicone treated(something like that I was told)= less friction and heat?, longer life for the oil.

Our sulphur content in Canada has dropped in our Diesel fuel in the last 20 years. This dirties the oil.

And look at the oil grades, I remember when CC and CD where all the rave., This is what I started to use years ago, now we passed Ce,F,G,H,I, and are on J.

Someone has suggested that this 3,000 mile oil change is the biggest scam the oil companies are pulling.

All I know, is that with 46,000 clicks on the new diesel, I have spent a lot of time and research in looking for a good synthetic oil, and I have found one that I will put in the benz for that extra protection. I have only used synthetics here in Canada in the winter, and some friends used it in there ski-doos, and bikes.

Maybe the oil change intervals really do mean something after all?????

But it is still hard to change my mind at times..............

I know there are major differences between diesel and gas. However, the 500E with over 100K miles has a cleaner engine/valvetrain than virtually any other MB engine with 35K miles on it that has had the usual 7500 mile services. I forget the exact sump capacity but I think it is around 8-9 quarts. It has had the normal MB service schedule with religious "in-between" changes using conventional 15w40 Quaker State. I know the twin-plug ignition engines are more effecient, cleaner burning, etc so perhaps they will age differently. I have seen how oil changes affect the DOHC engines. Also, the silicon crystal cylider liners are nothing new. They were used in the M119 V8's and the V12 starting in 92 model year. But it does lessen friction, reduce heat, and is more durable than the most metals. Your engine may be their debut in a diesel though. Considering the cost of engine repairs oil may be the cheapest insurance available.

Lee