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RI - do you have info on the break-in methods used for the 16 RS4 engines? I take delivery of the 335i Sunday and am debating whether to follow the factory’s suggested easy going break-in vs. the heat cycle and WOT drive it like you stole it method.
Reb, the method used varied across all the owners. Before I broke in mine, I read quite a bit and decided to remain within the parameters of the owner's manual. These days, if the engine breaks and you went over the break-in rev limits, your warranty can be denied, since the ECU logs this stuff. One of the things I'll point out is that you are not just breaking in the rings, your breaking in cams, cam chains, gears, differentials ... etc. Quite a few of these things should be allowed to break in over time.
Here's what the manual says, and what I did.
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Manual page 251
Up to 600 miles
- do not use full throttle
- the engine speed is not allowed to exceed a maximum of 6000 rpm
From 600 to 1200 miles
- do not use full throttle
- the engine speed is not allowed to exceed a maximum of 7000 rpm
From 1200 to 1500 miles
- Slowly and briefly increase the engine speed to 8250 rpm
Over 1500 miles
- you may now drive with an engine speed of 8250 rpm
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Now read my break-in recommendations, and you'll see that the fall within the letter of the Audi requirements.
The owner's manual contains some hard RPM and throttle position limits up to 1200 miles. (6000 rpm up to 600 miles, 7000 rpm up to 1200 miles, no full throttle until 1200 miles, and then only occasionally until 1500 miles) Within those limits the engine can still be wrung out pretty hard. (Torque peaks at 5500 rpm.) This type of engine, with Alusil cylinder walls, needs to have some serious power applied to the rings in hard acceleration and deceleration, in order to properly seat the rings in their grooves and against the cylinder walls. Deceleration using compression breaking is extremely helpful during the process, since it reverses the loads on the pistons and rings and allows all surfaces to wear-in well.
WOT is also very bad for this engine when it's not broken in. Mixture enrichment during WOT will blow-by into the oil and contaminate it. I generally recommend 3/4 throttle maximum until 1200 miles.
Remember, also, that this engine, by design, is not fully broken in until between 7K and 10K miles, due to the hard silicon cylinder walls.
I will point out that maximum piston ring forces occur at maximum engine torque, which is about 5500 rpm. This falls within even the early < 600 mile break-in RPM limit. You just aren't supposed to go to full throttle yet ... but, nothing in the manual says you can't get ---- close.
The key is to run the engine up hard, to maximize the ring/cylinder wall forces under acceleration, and then to allow the engine to use full compression breaking, to reverse those forces. This allows the rings to fully wear into the piston grooves and to lap themselves against the cylinder walls. This is much easier to do when the engine is young. As it gets older, deposits in the ring grooves can prevent full seating.
I broke in my engine fast and hard, within the RPM and throttle guidelines in the manual, with 2nd and 3rd gear hard acceleration and engine compression deceleration, after complete engine warmup, followed by cooldown, constant cruising in 3rd, 4th, 5th and 6th gears, and then repeating the hard acceleration. I did this every time I took the car out during the break in period, to seat the rings and wear-in the cylinder walls, which are hard silicon. At 1800 miles I changed the oil and filter.
Here are my oil consumption results:
1.5 Qts/1800 miles -- factory oil
Zero Qts/(1800 to 5000 miles) -- Elf Excellium LDX 5W-40
Zero Qts/(5000 to 6400 miles) -- Motul E-tech 8100 0W-40
Using an aggressive break-in regime will reduce oil consumption over the life of the engine, and increase maximum power output. I have had no oil consumption since changing out the factory oil at 1800 miles.
BTW, unless you over rev the engine, the most violent time your engine ever sees is those first few seconds after cold start. This is when wear is at it's highest. This is also why you want to start her, and drive her away, so that the engine and oil can warm as quickly as possible. Racing engines have dry sump heaters and pumps to bring the oil up to operating temperature and pressure prior to starting.
