Pissed Off.

**Buller_Scott** · 28-04-2009, 11:03 PM

There is an increasing trend towards buying diesel cars however some of the advice that is around is dangerous to say the least. Diesel cars are new to many dealer sales staff and I've heard them giving running in advice to customers that will seriously shorten the life and adversely affect the performance of the diesel cars that they are selling. This is particularly true for the new generation of hi-tech engines with modern turbochargers. It's not the fault of the sales staff...they just don't know any better.

One of the reasons that diesel engines outlast petrol engines is that the diesel combustion process is kinder to cylinder walls that that of the petrol engine process. This means that in the early life of the engine when the rings are bedding in it's easy to glaze the cylinder walls. The worst treatment that you can give your new engine is to run it at constant high revs...for example on a freeway or on long, straight, flat country roads until the rings have had a chance to bed in. Ironically, city driving is excellent for running in an engine as it gives exactly the opposite conditions...as long as the engine and particularly the oil gets up to full working temperatures for a reasonably sustained period. Running to the shops or taking the kids to the local school and then shutting down is a killer. Diesels thrive on hard work and long periods of running.

Below is an excerpt from a post on a TDI forum overseas. I don't think I've infringed copyright here but I'm sure the author (who is a very knowledgeable poster and is an experienced trade guy) wouldn't mind. I agree with everything he says or I wouldn't quote him.

Rules that apply for the life of the car
-When the engine is cold rev the engine to at least 2,500 rpms.
-When the engine is warmed up rev the engine to no less than 3,000 rpms.
The reason for this is to keep the turbo on boost, clear the VNT guide vanes and apply firm pressure to the rings for optimal sealing against blow-by gasses. The rings need the boost to seal since it’s a turbo charged engine, babying the engine is detrimental and will lead to issues with compression if done so for very long.

First 1600km
Keep rpms below 3,800. Avoid steady rpms. Frequent firm application of power is strongly recommended up to 3,800 rpm. Avoid the use of cruise control so that you naturally fluctuate the power with your foot.

1,600-8,000 km
Use the full ~5,000 rpm power range. Avoid steady rpms. Avoid the use of cruise control. Frequent application of full throttle is recommended to help seat the rings. City driving is ideal for breaking in a TDI due to frequent stops and acceleration. Once you get to 8,000 km change the oil and perform your first service per the manual

8,000-16,000 km
Use of the cruise control is ok at this point since most of the initial break in has occurred. Continue to use occasional full throttle accelerations to continue to seat the rings. You will notice the engine become slightly louder during this phase due to less friction from the engine breaking in (normal for a diesel to become louder under lighter loads). If your going on a long drive and you are using the cruise, every so often step on the peddle to accelerate up about 30 kmph then coast back down to your preset speed.

16,000-100,000km
This is when the rest of the break in occurs. The engine from the factory will check out with about 475psi of compression pressure out of the crate. It will take at least 10,000 km to reach the peak pressure of 550psi. For the most part once you get to 16,000 km your compression will be around 510psi meaning that most of the break in has occurred.

100,000-the life of the motor
The engines I have seen so far using a 5w40 oil are maintaining 550 psi of compression pressure with over 300,000 km on the odometer. The owners have followed the advice above and do not have any oil consumption issues. This also means that with the higher pressure the engine is more efficient returning optimal fuel economy and reduced smoke output.

**Buller_Scott** · 28-04-2009, 11:08 PM

as for not putting diesel into your engine....

there's a good story on tdi club from a guy in the states- from what i read, diesel awareness is not very widespread when it comes to diesel CARS.

something along the lines of a guy watched as 4 thugs popped his fuel cap and began to siphon fuel out of his new beetle (diesel) one night in his work carpark. he waited inside, and watched as they poured the fuel into their pickup, started, then died before they could get out of the parking lot.

poor kids......