98RON

I've always been quite intrigued by the conflicting opinions as to how best to run an engine in. At the two ends of the scale are the ultra-cautious (more than Honda even recommend) 1000 miles >6K rpm and then slowly introducing VTEC over the NEXT 1000 miles versus the 'drive it like ya stole it' from day one approach. And everything in between.

Most of the discussion about the 'drove it like ya stole it' from day one approach centres around the fact that whilst the engine might well be a bit quicker and more willing to rev out more keenly and smoothly, there is also an increased chance that it will catastrophically fail/blow at a relatively premature stage - i.e. well before the seemingly typical >120K miles for an engine ran in in strict accordance with the manual (or even more cautiously).

I don't think there is much doubt that in reality the vast majority of dealer ex-demo S2Ks will see quite a lot of VTEC action from day one and are, as such, very much run in more towards the 'drive it like ya stole it' from day one school of thought. (Moreover, they will also likely on occasion have NOT been warmed through properly before VTEC-ing during their stint as demos.)

Contrastingly, most cars owned privately from new will tend to be ran in much more carefully i.e. as per Honda's recommendations or even more cautiously still.

This got me thinking about trying to find out if dealer ex-demo S2K engines blow up more often AND MORE PREMATURELY than cars owned privately from new. I know that plenty here have had engines blow up at 80K miles or earlier and found myself wondering whether or not there was any relatively clear association between dealer ex-demos and premature catastrophic engine failure. If ANY engine might well be prone to early failure due to poor running it, it arguably should be the S2K given the highly tuned/strung nature of the stock engine to start with.

Hence the above somewhat crude poll: whilst very basic, it might nonetheless be in some way indicative/interesting IF it transpires that most premature engine failures have occurred with dealer ex-demos (which FWIW I personally doubt BTW...).

When you vote, please also post a quick associated reply stating the car's year of manufacture along with any other notable details/circumstances including how you ran the car in (cautiously or drove it like ya stole it!) if NOT originally an ex-demo.

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ace123

There's probably not enough of a polling base to get data like this. Honestly, has anyone on the boards had an engine blow before 100k without 1) FI/nitrous, 2) running out of oil, or 3) landing a money shift?

I think by the very fact that it is so rare to hear of cars with blown engines (from other causes) at that low a mileage shows that break-in can't do THAT much damage. Perhaps it cuts the relative life around the 150k+ mark, but at that point I'd expect the driving style and other things to have left a much greater mark on the engine than anything.

Mine was demoed to 700 miles, and it's never had any engine issues so far, but I'm only in the mid-20k mileage range. Well worth the $3k I saved on the purchase price, IMO.

Ted H

Plus, you're going to have to take into account the relative percentage of dealer-demos to non-dealer-demos. Thus making it even more difficult to make this work, considering your "polling base."

Good luck though.

hirev

Not sure what you can get from this...my car was a demo, had 72 miles on it , at 6 years and 39,000 miles it uses no oil and runs like a champ, original clutch and brakes as well.

98RON

Many thanks for the replies guys. I knew that this was a difficult one to try for all sorts of reasons but I had to have a go anyway!

So far I've got 8 votes here on the UK board and 3 votes here from guys whose engines DID blow before 80K miles (none FI'd SFAIAA) and NONE of which were dealer ex-demos. So 11 premature engine failures all with cars privately-owned from new (and, as such, likely ran in rather more carefully than dealer ex-demos which we all know are VTEC'd extensively from day one on test drives - who'd test a S2K and NOT VTEC it?!).

The results do go at least a little way to reinforcing what I've suspected all along which is that run-in technique (cautious approach vs 'drive it like ya stole it from day one' approach) makes little or no difference to the longevity of the engine - despite the protestations of those who insist that premature and catastrophic engine failures are far more likely following 'drive it like ya stole it from day one' engine break-in.

98

Ted H

As I said, you'll need to take in account the relative percentage of demos to non-demos. Your data reflects little to nothing... particularly with the low sample size. Don't take any offense by this, but you need a larger base to survey.

98RON

No offence taken.

I do find it quite interesting, however, that of ALL the 11 relatively premature engine failures logged/polled thus far, NONE were in cars that started out life as dealer ex-demos.

Here in the UK quite a significant proportion of S2Ks (and other sportscars in general) start life as dealer ex-demos and, as such, I'd have expected to see a few engine failures in that group rather than all of them in the privately-owned from day one group.

Whilst I appreciate the validity of your comments regarding the difficulties here, I will, if nothing else, conclude from this albeit very limited evidence that there is NOTHING WHATSOEVER here to reinforce the assertion that engines NOT cautiously ran in (dealer ex-demos)will fail sooner than engines that ARE typically more cautiously ran in (privately owned from day one).

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starchland

For me, waiting til 1000 miles before hitting VTEC is a little bit much. I mean, you have to remember that VTEC is a huge part of this engine, and not letting those components break in until 1000 miles may not be the best thing either.

Also, Honda designed the car to only engage VTEC when the ecu believes it is safe to do so (so hitting VTEC...or trying to hit VTEC prematurely before engine warm up may not be an issue?)

I mean, what percent of people even follow a break-in schedule, let alone read the owners manual?

Just food for thought. It would be an interesting correlation if you can find it.

Moddiction

What are the engine failures from? Most likely running out of oil or money shift etc as mentioned before. I highly doubt those engines blew for no apperent reason...

98RON

and, like you, am of the opinion that VTEC should be broken (at least to some minimal extent) along with the rest of the engine.

My car has now done 800 miles and what follows is how I've run my own engine in so far - with engine always fully warmed through before exceeding 4K rpm:

1. 0-200 miles under 5.5K revs and LOTS of variety in throttle openings/engine loadings, gears used (no 6th gear at 50mph for miles - I'd instead be in third or fourth up to 5.5K rpm and then letting the engine brake from 5.5K rpm in same gear rather than changing up). NO lugging from low revs in high gears.

2. 200-400 miles under 6K rpm as above.

(By this stage I'd done 400 miles which because of frequent use of lower gears and engine braking therein will IMO easily equate to 800 miles of cruising along a motorway in 6th at 4-5K rpm.)

3. 400-600 miles as per above but gradually introducing the occasional short 2nd or 3rd gear burst up to 6.5/7K rpm or so (not full throttle).

4. 600 - 800 miles quite a lot of VTECing to 7, 7.5 and (more latterly) 8K rpm - predominantly in 2nd, 3rd and 4th and no full throttle more than a couple of seconds.

5. Next comes the 800 - 1000 miles during which I'll be progressively be upping the ante with some comprehensive limitter-hitting around the 1000 mile mark.

And that'll be that. Not the most cautious approach admittedly, but one I'm totally satisfied with given everything I've ever read and know firsthand about running engines in to best seal the rings (whilst at the same time sensibly breaking in all other components both engine and otherwise) so as to get the best mix of keen free-revving performance and long-term reliability.

The engine feels strong and very smooth and has to date dropped one diamond on dipstick if that (and only during the last 300 miles owing to preliminary use of VTEC).

98