Got a new diesel car? here are some run-in tips for you.

I still remember my first new car. I loved it so much, so I sat on the driver seat from time to time even when I was not driving. I couldn’t believe I was able to buy a new car on my own. Since I cared for my new car so much, I wanted to take great care of it. I started Googling about the new car run-in tips. Run-in is “the procedure of conditioning a new piece of equipment by giving it an initial period of running, usually under light load, but sometimes under heavy load or normal load” according to Wikipedia.

Most people say that with modern cars, this is not necessary. Therefore, you can drive it however you like from day one. I don’t believe in this. Any new machine especially the one with a lot of parts assembled require time to let parts blend in nicely.


Here are some tips I apply to all of my new cars so far. I typically drive a car for 10 years or so, I never had any major maintenance issues nor performance degradation after applying these techniques in the first 5,000 km or so.

1)  Read the owner’s manual carefully from page 1.
A lot of people ignore the owner’s manual and just start driving. This is especially true for experienced drivers. Of course, in most cases, there wouldn’t be any issues until you run into one. But I strongly recommend you to read the owner’s manual from page 1 till the end. As an example, some gasoline model requires you to use premium gasoline as opposed to regular gasoline. If you continue to fuel a regular one, it will ruin the engine eventually. In other words, not reading the owner’s manual might cause you to replace an engine one day!


2)  Replace engine oil regularly. Within the first 5,000 km or so, it’s best to replace it.

In the case of the BMW diesel engine, engine oil replacement sign will appear after 15,000 km or so. But when you buy a new car, it’s best to replace it within the first 5,000 km or so. There’s been a huge debate about this whether or not this is not required with a modern car but I still believe that it will not hurt! Think about metals in general. Even if you carve it carefully,  when you use it for the first time, it doesn’t feel smooth but over time, it feels very smooth. This means any parts whether they are metal based machine or wooden parts, you need time to let all parts blend in nice and smooth.

Oil change a little before its limit help a lot.
Oil change a little before its limit help a lot.

3) Do not speed up abruptly. No more than 3,000 rpm until you reach 5,000 km or so.

I love to speed up(or course in a safe way). That’s why I am always attracted to performance cars such as the BMW 420D Gran Coupe. However, until I reach the first 5,000 km, I don’t accelerate more than 3,000 rpm. In other words, I put on gas gently when I am in the run-in process. Again, there’s been debates about this run-in process, but it doesn’t hurt to let all engine parts settle down nicely. Before you know it, you reach 5,000 km. Then let the game on!

Game on!

4) (Carbon) sludge buildup.

Especially with the diesel engine, whether or not your car complies with Euro-6 standards, from the moment you start driving, carbon sludge starts building up in the intake manifold area. There is no way you can stop this. Of course, there are some ways to minimize it but eventually, you get carbon sludge buildup issue. When this happens, you need to clean it manually otherwise, your car performance starts degrading substantially.

Some people say you don’t need to think about this issue in the first few years. But I recommend you to take it seriously from day 1. There is a way to avoid the sludge buildup process.

D Clean is an adaptor type product. When D Clean is installed in front of intake manifold, you don’t need to worry about sludge buildup issue forever. The only thing you need to do is to replace cleaning liquid whenever you change your engine oil.

D Clean cleaning liquid refill.
D Clean cleaning liquid refill.

Check out this article.

Well, there might be more run-in tips. But I’ve been applied the above techniques for new cars. Since then, I didn’t run into any issues with my cars. Am I simply lucky? Maybe. But what if these are all you have to do to keep your car as good as new in the next 10 years or more? I’d like to conclude my story as saying “It doesn’t hurt to try!”