Breaking in new car

[gangstarrrrr]

Chaps any thoughts on how to break in the engine on a new car?

Pick up my new S4 avant black edition this week and have heard 2 schools of thoughts on this.

One is the conventional wisdom of taking it easy on the engine initially, though I don't recall seeing any hard numbers...

Other side of it says to rev the engine hard and let it engine brake in all the different gears and to do it as soon as you get it. Helps apply pressure to some part of the engine block and helps reduce oil usage. This is from Audi-world.

Any thoughts here? How did you do your S/RS from new?

[HYFR]

For the last 2.5yrs I have had x3 brand new S cars and x3 brand new RS cars

imo don't pussy foot around, once the oil is up to temp, give it the beans

[MikeFish]

But D_K do you ever keep any of those cars long enough to see the long term effects of giving them beans at low mileage?

[HYFR]

I do about a years worth of average mileage in each one and they don't ask for a drop of oil and never miss a beat

My boss had the same car as me at the time and he drove mine and said it felt stronger

[MikeFish]

I've heard similar stories about engines performing better when given a bit of wells early on, dealership demo cars are prime examples of this, they generally perform well. My fear would be if I was keeping longer if there was any longer term issues.
If I was only keeping the car for a year or so then I'd be inclined to follow D_Ks advice.

[Dave_Hedgehog]

he first 2k miles of my car where done by the dealership and by 5k miles the engine had gone bang

i take the middle ground i don't mind using revs (which are needed to get oil pressure up) but i avoid heavy load, gradually building the load up and moving towards the red line as the first 1k miles are put on it

[adsgreen]

In my experience its a bit of both.
Engines are much improved so running in isn't as critical but you'll still get benefits.
The key things to avoid is cold oil and load.
The engine has to be up to temp so baby it until then. if you have to accelerate hard it's better to stay in a lower gear for longer than change up and keep the revs low.

For the first few hundred miles its worth being quite light on the throttle - say no more than 50% and reasonably low rpm (I use under 3k).
After about 500-600 miles I use up to 75% throttle and 100% rpm but stay away from the limiter.
On multi cam profile cars you need to make sure that the 'power' setting is also broken in so need to venture up the higher end if the rpm band. High revs are fine on a warm engine under light load... So slight throttle in 1st up to 30/40 is fine but 4th gear at 20-30 is considerably worse.

Avoid crushing at steady speed and rpm such as a motorway. If you must do this then vary speed and gears a little to avoid sticking to the same steady state.

As for brakes it's pretty much normal bedding in process... On the road do a hundred or two miles then do the standard bedding in process of a couple of hard stops and then couple really hard stops then allow to cool.

[gangstarrrrr]

On multi cam profile cars you need to make sure that the 'power' setting is also broken in so need to venture up the higher end if the rpm band. High revs are fine on a warm engine under light load... So slight throttle in 1st up to 30/40 is fine but 4th gear at 20-30 is considerably worse.

What is a multi cam profile car? Would the S4 fall into this category? Apologies, I'm not well versed in the intricacies of engines but I hope ownership and lurking around on RS246 will change that!

[adsgreen]

Pretty much every car nowdays has some form of variable cam timing. Honda call it "VTEC", Toyota "VVTI-L" and many others. The principle is broadly the same though on all of them. The cam shaft is not fixed to the timing belt/chain but goes through a drive mechanism that can advance and <beep> the position of the camshaft depending on signals from the ECU. The basic idea is that a low rpm high economy steady state cruising engine would need cam's timed such that there was almost zero overlap between intake and exhaust where as high rpm and loads need huge overlaps. Variable valve timing allows both on the same engine. As an aside, anybody who has seen a race engine with no variable valves will not that at low rpm it's (for want of a better word) "a bastard" - lumpy, lethargic, stuttery... This is due to big overlapping valves outside their design range (and not helped by super light weight flywheels).

Anyway... back on topic... When running in an engine you need to make sure that both "efficiency" and "power" cam profiles are properly worn in. So for example, on the rs4 you'd need to venture up above 5.5k rpm in order to make sure that the profile is fully switched over to power. The key point is that 99% of systems are based on rpm only so you don't need to push the throttle down lots just enough to allow the engine to reach the higher rpm. The honda system is pretty funky as it changes the cam switch over point depending on load... the more throttle the lower down the rpm range the switch happens. Toyota's is fixed rpm but it also varies valve lift in a very complicated way.