From the motorbike thread as it doesn't really belong in there -
viewtopic.php?p=954723#p954723Quote:
Yeah, whoever ran the engine in on your car was a fucking bellend and ragged it way past safe limits during the run-in period.
So instead of your piston rings making a proper seal in the cylinders, there's little bits that oil can seep through into the combustion chamber. I suppose if anything it should increase power slightly (more energy in the combustion?) but it's not good for the engine.
Similar fault on the early 140bhp 7th gen Celicas, although in that instance it was a manufacturing fault that made the piston rings weaken over time and become misshapen, allowing the oil to leak through. Worst case I ever heard of on that car was burning a litre of oil for every 200 miles.
I've done a fair bit of reading on this and opinion is divided on why the engine in the B8 S4 uses oil, (note the B8.5 (facelift) S4 doesn't, so Audi changed something but didn't tell anyone what it was), one school of thought is that Audi's 'gentle run-in' policy is actually the problem, and ones that were given a bit more beans from new don't exhibit the problem. (The rings harden better and quicker, or something?)
There is consensus however that once your S4's 'loss rate' has been established it won't get any worse or better, that's just how much oil your car is going to use, and certainly mine has been absolutely steady at 1400-1500 miles per litre top-up required.
Don't get me wrong, I'd much rather I didn't have to keep putting a litre of oil in it that regularly, even using the Fuch's oil off Amazon it's not exactly super-cheap (as you have to use oil that meets the VW/Audi spec, and aren't supposed to just chuck any 5W/30 oil in there), but it's not that much of a faff and it's not detracting from my overall enjoyment of the car (unlike the Merc and its various problems, which I was somewhat fucked off with after the same duration of ownership).
I went into S4 ownership with my eyes open, it was never going to be cheap car to own overall, if I'd wanted that I'd just buy a ten year old Ford Focus, so the oil 'situation' doesn't particularly bother me.
EDIT - Plus, I'll only have it for another 12 months or so anyway, like all cars in my life, it's just passing through really