FrankTsui

Hey guys

Just got my Audi S4 and the manual says the engine must be broken in for first 1000miles.

So I babied it for first 1000miles and it is 1050miles on the odo. Can't wait to drive it so hard! Should I extent the break in mileage brefore going to tracks(hyper aggressive driving) or I am good after 1000mliles'mark? and do I need to do the oil change service after 1000miles?

There is another voice about the break in period that you should drive like you stole it from the very first day. How do you think about the break in period and when did you start to drive it hard?

Many mant thanks!

Aviator6

"There is another voice about the break in period that you should drive like you stole it from the very first day."
Yeah, that's been around forever, but it is just plain STUPID. If the company that builds the car says to break it in for 1000 miles, then I will go along with that. You should be good to run the track, but do a cool down period after any hard runs.

FrankTsui

Yeah. It's never go wrong to follow the manufacturer's manual.
Just wanna know why there are differences between different car makers? say MB BMW has different description of the break-in period. Shouldn't this depend on the engines? if so, why all cars from the same brand follow the same principle of break-in? (ie A4/S4/RS4 have the same period of break-in period at 1500 km as the manual indicates however the engines are different)

Dan99

When an engine is first manufactured all of the components have new and fresh surfaces. They are also soft. The break-in period allows the new metal parts to seat against each other. So, for example, breaking in allows the piston rings and cylinder walls to create a better seal. Think of it as sharpening a knife with the finest grit stone available. The rings and cylinder walls both become smoother and fit together better afterward. But, in addition, it allows the two different surfaces to harden so they will last longer. Think of this as hammering a glowing piece of metal on an anvil - as you beat the surface it compresses the top layer of the metal and it hardens. Consider internal parts like valve stems. If you run the engine hard when all the surfaces are soft, you will have premature wear and your engine will burn oil sooner. Break-in periods improve the fit of newly machined surfaces, and also hardens the soft new surfaces gradually, which results in less wear over time.

Driving it like you stole it will decrease the time it takes to sand the two surfaces, but it by-passes the hardening process, so you will accelerate wear on all of the moving parts. If you want your engine to last longer and burn less oil, don't drive it like you stole it. If you are going to the drag strip or track with a new engine and you plan to tear down and rebuild the engine periodically, drive it like you stole it. But, the factory tolerances will not be appropriate as all the components will be too tight. Racing engines are generally machined a bit looser and the assumption is that they have a short life span and will be rebuilt sooner.

Break-in applies to every internal combustion engine, not just Audis. The only exception would be for the few elite performance-oriented engines that are broken in at the factory, but even that does not break in the transmission, rear end, suspension components, axle bearings, etc. so you are accelerating wear somewhere if you drive any new car like you stole it.

I broke in my engine according to the manual, then gradually drove it more aggressively on the street. I took it to the track for the first time at about 3500 miles and changed the oil soon after. Even though the factory change interval is 10,000 miles, I continue change oil every 5,000 miles.

I have used this general approach for decades since I read about it in some publication and none of my cars have burned oil. This includes my current RS5 and both of my previous S4s.

If you are having trouble waiting, just go on a road trip, but remember to vary speeds during the initial break-in. Watch the tach and vary rpms as you drive. Since the stresses on all components vary with speed, you want to vary the speed enough to allow the components to break-in across a range of engine speeds. But, that does not give you permission to drive hard or at high rpms until the manufacturers break-in period is over.