Power loss over time

[Rdawson]

Hi all,

I'm trying to establish whether there's any consensus on engine power loss over time. My 2007 N54 has put down around 88,000 miles, but had new turbos and injectors at 60,000. It seems to be running really well. It will still pull strongly uphill in 6th gear from 2,000 rpm, which I appreciate is a characteristic of the engine, but, would the engine likely have felt more 'lively' or 'strong' at, say, 20,000 miles? I only bought the car at 78,000 miles and I guess I haven't felt any change in that short space of time, but what are your thoughts on power loss over time - say out beyong 100,000 miles? The engine has always been serviced at the required intervals or better. I guess I just don't want to think of the engine becoming noticeably weaker over the next couple of years! Anyone had their higher mileage engines dyno tested and been pleasantly surprised by the results??

Cheers,
Rob

[BritishRacinGrin]

I started this thread in GG some time ago which confirmed my suspicions...

http://www.pistonheads.com/gassing/topic.asp?h=2&a...

[Rdawson]

That's the reply I was looking for! Thanks a lot.

[Vixpy1]

I banged my 222k 840ci on the dyno a couple of weeks ago to check a setting on the dyno.

282Bhp.

[BritishRacinGrin]

I think it's quite widely recognised that BMW engines quite often beat their book figures even after a lifetime's work, I have certainly heard this about the petrol N/A straight sixes anyway. I really must get my old 525i on a rolling road at some point, I'm curious... it feels good to me after 130k miles.

[Esseesse]

Alfa V6's seem to get more powerful the older they get.

[Lowtimer]

Marginal power losses on engines which have not been abused or totally worn out are usually in the periphery (boost / induction leaks, poor HT leads / distributor caps / plugs), or things like oil sludge and coking, partially blocked filters etc.

An engine with all that stuff in order, that has been run sympathetically at reasonably high power settings (not idled round town all its life) and had regular fluid and oil changes generally puts out more at 100,000 miles than it did at 2,000 miles, simply due to the substantial reduction in internal friction.

[tgr]

So my car is now more powerful than it was for the original owner? Fantastisch

[Lowtimer]

Most likely, yes, if you've kept it right up to the mark.

Back in the '90s I think it was Autocar who had a very long term test Mark II Golf GTI 16V and did the full acceleration figures on it several times from their original road test onwards. It's a long time ago but I think it was about 45,000 miles when they did the last set of figures, and every set was better than the set before.

[Kawasicki]

I had a 120k mile 318is, which would not struggle to hit the rev limiter at a real 131mph, which was the claimed top speed of the car. I drove it on the limiter in 5th for 1000's of miles, which didn't seem to bother it at all.

[BritishRacinGrin]

My Caterham racing car used to use a very standard 1600 8v cavalier engine. The flywheel, the camshaft, the hydraulic tappets etc all standard GM parts. Interestingly I once fitted a well used engine which had been a spare, had done a lot of races and used a not insignificant amount of oil. Anyway, it seems that these engines would go through a phase of being a complete screamer once they were well loosened up, because this engine was a bit quicker than any of the much fresher engines I had used previously!