The_Judge

My 2018 E400 has been driven a whopping 1,376 miles since its last service on October 19, 2023, and my Mercedes dealer is now bugging me to bring it in for service once again. The car is running fine, no problems or irregularities.

Question: Is service necessary at this point?

Thanks.

JettaRed

iTrader: (1)

Some services are time-driven. Three most critical services are oil changes (6 months), transmission service (5 years), and brake fluid service (2 years).

So, even with only 1,376 miles since the last service, you should get your oil changed since it's going on 11 months. When was your brake fluid last done? Transmission service?

Ask the dealer what needs to be done.

JettaRed

iTrader: (1)

Oil viscosity does break down with time. And with a turbo car, you have more opportunities to cause damage to the engine and turbo when you skip or delay essential services.

ua549

Service should be by miles or time whichever occurs first. For me it is time, every year on the purchase anniversary date (about 2,500 miles).

E300-18

If the car isn't under warrantee, I think it comes down to a personal decision. Mercedes recommends oil changes every 12 months or 10,000 miles. I'm always under in miles, but not as much as you. I don't believe that there is any magical deterioration that starts happening right at 12 months, and I'll let it go another month or two with low milage.

JettaRed

iTrader: (1)

He should change the oil at 6 months. Never wait 10,000 miles or 12 months to change oil if you want to get lots of miles out of the engine.

E300-18

What is your source for that information? Mercedes recommends oil changes every 12 months or 10,000 miles for my car.

JTK44

As you know there are so many posts on the subject of low mileage and whether an oil change is necessary: whether changing the brake fluid every 20K miles is even necessary, never mind less than 2,000 miles.

Suggest you read those many threads and posts and come to your own conclusion.

As to the tranny oil change at 5 years vs. 50,000 miles:

I suspect as time goes on more will have to make that decision: Having worked on cars all my life, the one thing that manufacturers do well now is make transmissions. Most are bullet proof. My own opinion is mileage and not time determines when tranny fluid should be changed. To answer your question until your car hits 50K miles I would not even consider changing the transmission fluid.

Hope this helps

JettaRed

iTrader: (1)

Asking the dealer what needs to be done will tell you what they would do and then you can decide to have them do it, have an independent shop do it, or do it yourself. Actually, the transmission service interval for my SL is 77,500 miles or 5 years. And changing the brake fluid every two years has long been the recommended interval among many manufacturers. The whole point is that performing these services more often than recommended is NOT a waste of money when compared to the cost of repairs. The OP's E400 with the M276.8XX engine is fairly bulletproof, however it can never hurt to perform these services more often than the absolute minimum. I right now have a 2004 Audi TT with over 250,000 miles with the same engine, transmission, and turbo. It has had its oil changed every 5000 miles or less from the beginning. I've read the discussions and watched the videos and my conclusion is to perform these services as I originally stated.

However, it's your decision what to do with your car.

L1Wolf

There are numerous opinions online both for and against following the manufactures suggested oil change intervals. Search for it and there will be no shortage of info. Is a 10K oil change interval best for the engine or best for the manufacturer to meet government regulations. Can you go 10K or 12 months before changing oil? Maybe. Should you? Not in my opinion. One thing is clear. Changing oil more often can't harm the engine. I did my first oil change of my new 2025 E450 at 722 miles which was just 10 days after purchasing it. Call me crazy but I believe it to be cheep insurance. It cost me $120 in materials and about 2 hours of my time. I'll change it two more times before the 10K change that I'll let the dealership do. I plan on keeping the car for a long time.