Running in a new engine
Discussion
When a user manual states "avoid prolonged periods of steady speed driving for the first 600 miles", how long is this period? 10 minutes? 200 miles?
I understand it can lead to cylinder glazing, but how likely is this given motorway cruising is a medium load at medium revs? Or is it more that it just prolongs the running in time?
Thanks in advance!
I understand it can lead to cylinder glazing, but how likely is this given motorway cruising is a medium load at medium revs? Or is it more that it just prolongs the running in time?
Thanks in advance!
Ok I'm really pi55ed off now having researched into this a great deal. We bought a new car and decided not to opt for an ex demo mainly because I could treat it well and be safe in the knowledge it's been given the best start for being long lived (I'd like to keep the car indefinitely!).
However, the first few journeys it's had were mostly motorways which seemed an ideal way to run it in at the time by not having to over rev it or have it labour. I'd read about varying the revs in the manual after the first trip, but by this time the car had already clocked up 200 miles at a steady speed. And to get back in a reasonable time I also had to motorway it and varying the speed was not always practical.
Had the dealer told me this before we'd driven off I would have known to opt for a totally different journey! So now for the rest of the car's life I'm going to wonder whether the piston rings haven't sealed properly, meaning less power, worse fuel consumption, oil consumption and poorer longevity. It totally negates having spent my hard earned to get a new car in the first place for me :-(
However, the first few journeys it's had were mostly motorways which seemed an ideal way to run it in at the time by not having to over rev it or have it labour. I'd read about varying the revs in the manual after the first trip, but by this time the car had already clocked up 200 miles at a steady speed. And to get back in a reasonable time I also had to motorway it and varying the speed was not always practical.
Had the dealer told me this before we'd driven off I would have known to opt for a totally different journey! So now for the rest of the car's life I'm going to wonder whether the piston rings haven't sealed properly, meaning less power, worse fuel consumption, oil consumption and poorer longevity. It totally negates having spent my hard earned to get a new car in the first place for me :-(
Edited by VeeFource on Thursday 8th October 23:15
HustleRussell said:
If it makes you feel any better it almost certainly has the wrong oil in it for a break-in period anyway.
I'd have thought that would make the process of running in even more important. Ultimately I don't know how much it's effected it, which is hugely annoying in itself.Can't believe I wasn't aware of it too just from my own reading up on cars over all those years either
mp3manager said:
As an ex-car transporter driver, guys like me, (and the dozen or so other people who drive your new car before you go into it ), give your car absolute death. You can call it 'perks of the job'.
However if it makes you sleep better at night, you carry-on believing that your car was treated with kid-gloves and driven like Miss Daisy, before you bought it.
Benrad said:
I work in engine development, we have two different ways of being in an engine. One with kid gloves if we need really consistent performance and emissions for development. However if it just needs a quick test then it gets put straight to max power and stays there for 10 hours. Your car will be fine, chill and enjoy it!
If it's a modern smallish turbo engine then on the motorway it's actually working pretty hard and will have been nice and hot
Cheers Benrad! Your reply is the best I could have hoped for given you have the experience to actually really know what you're talking about If it's a modern smallish turbo engine then on the motorway it's actually working pretty hard and will have been nice and hot
It's an n/a 1.6 and would have been working at about 3k rpm at 70mph so it should have been reasonable loaded. I've read engines can develop a flat spot if held at constant revs during break in but the jury's out on whether that only applied to older carbureted engines or not and also no one knows why. Either way would it not take the engine accelerating and decelerating to cause the rings to flex and spin around to round the cylinders properly?
Ozzie Osmond said:
Absolutely not. I've read many times on the internet that abusing a new car is good for the engine, leading to long-term improvements in power, emissions and reliability. Keep up the good work.
It's a controversial subject. But through all my research I found it's only racing engines that tend to get this treatment as it's the quickest way of getting the rings to seal. Fine for that application, but if you intend to keep the car very long term it's not advisable. Too much load causes localised heat build up at the peaks on the surface of a honed cylinder and can lead to the oil overheating which leads to glazing. Too little load is even worse as the rings won't bed in and over time the thicker oil film oxidises and also leads to glazing.The latter is a bigger problem on high power engines as it takes a lot more conscious effort to ensure it's being regularly loaded at 50-75% (depending on break in stage). So high power engines do need to be flexed but certainly not thrashed seems to be the general consensus.
nickfrog said:
Why would they ? All engine are pre-run in the factory by a dedicated team, all part of the service.
In the process, they also run in the box, clutch, tyres, discs etc etc. They have a dedicated track, they do a good 1000 miles and then rewind the mileage back.
Just buy it and cane it.
Not true. I work with a manufacturing engineer whom used to work at engine plants. He's not sure on how long is too long for steady state driving, but he did tell me engines are only cold tested. I.e. They get spun up with an electric motor with only oil in to test all sorts of different things. Every 50th engine is taken for "torture testing" and is subject to lots of horrible things running hot. But the engine is then scrapped.In the process, they also run in the box, clutch, tyres, discs etc etc. They have a dedicated track, they do a good 1000 miles and then rewind the mileage back.
Just buy it and cane it.
After they leave the factory they're assembled into the car at the final assembly plant and put on a dyno to check the car meets performance criteria etc but this is only for a few minutes. The cars are then driven around a test circuit to check for rattles etc and to make sure there are no suspension/steering/drivetrain issues.
With much better manufacturing and materials it doesn't take anything like as long to bed in a new engine compared to yesteryear. But they still need treating with care to ensure everything beds in properly, particularly the piston rings over and above anything else.
I knew most of this before I took delivery of the car but somehow missed the part about steady state driving, dohhh
Edited by VeeFource on Friday 9th October 10:15
For anyone interested in this subject, I found a great engineering article which states just how important breaking a new engine in is in the very early stages (skip to section 9.1.1 on page 72):
http://www.vtt.fi/inf/pdf/tiedotteet/2002/T2178.pd...
Interesting (to me anyway lol) how the cylinder liner wears 12 times more in the first hour than the following two and even more so that 84% of piston ring wear takes place in the first 22 minutes. This latter point is the most important as it's a much harder material than the liner.
It's good news for me anyways as the car didn't hit the motorway for the first 40 mins and even the hour after it was slowly taken up from 50-70mph.
http://www.vtt.fi/inf/pdf/tiedotteet/2002/T2178.pd...
Interesting (to me anyway lol) how the cylinder liner wears 12 times more in the first hour than the following two and even more so that 84% of piston ring wear takes place in the first 22 minutes. This latter point is the most important as it's a much harder material than the liner.
It's good news for me anyways as the car didn't hit the motorway for the first 40 mins and even the hour after it was slowly taken up from 50-70mph.
SHutchinson said:
Are you one of lifes worriers by any chance?
Haha, guess I am when it comes to things like this. Was more annoyed than anything though that this isn't pointed out to customers buying a new car, especially as this is a good reason to spend the extra over an ex demo which will have been thrashed to death from cold.conkerman said:
If it breaks it'll be quite soon and will be under warranty. If it doesn't she'll be reet.
Wow, that’s some black and white thinking right there! The grey bit is that if the rings don’t seat and you glaze your cylinders you get less power, worse economy, high oil consumption & less longevity. I plan to keep the car a long time so these things matter, even though I can understand why most people wouldn’t care less. But given they’re easily avoided too with just a little bit of knowledge, why be ignorant when you’ve just paid top whack? Think about how much people pay upgrading their intakes and exhausts too just to get a few more bhp when you can get them for free at the beginning..38911 said:
I would be fuming.
Personally I would sell the car.
And sue the dealer for not telling you.
Having covered it's first 200 miles at a steady speed on the motorway, it's bound to be knackered.
Or in reality I would accept that it's a bog standard wheezy 1.6 four-pot run of the mill mass produced engine and actually it makes absolutely naff all difference how it's run in.
As a previous poster said, by the time a new car is delivered, it's already been thrashed by a dozen people, none of whom give a monkeys about treating your new pride and joy with any sympathy whatsoever. Oh, and you can ignore what the odometer says - until the dealer commissions / PDIs the car, modern cars are in 'transit mode' and the odometer stays at zero. The 4 miles that were on the clock when you bought it were all done after the car had arrived at the dealers.
So you've clicked on a thread on a subject you obviously don't really care about and read through all of it only so you can belittle someone else’s concerns?Personally I would sell the car.
And sue the dealer for not telling you.
Having covered it's first 200 miles at a steady speed on the motorway, it's bound to be knackered.
Or in reality I would accept that it's a bog standard wheezy 1.6 four-pot run of the mill mass produced engine and actually it makes absolutely naff all difference how it's run in.
As a previous poster said, by the time a new car is delivered, it's already been thrashed by a dozen people, none of whom give a monkeys about treating your new pride and joy with any sympathy whatsoever. Oh, and you can ignore what the odometer says - until the dealer commissions / PDIs the car, modern cars are in 'transit mode' and the odometer stays at zero. The 4 miles that were on the clock when you bought it were all done after the car had arrived at the dealers.
How do you know it’s a ”bog standard wheezy 1.6 four-pot”? It could be a Lotus Elise for all you know.
I might seem overly concerned about the technicalities of running in an engine that you clearly struggle to grasp, but at least I don’t have to worry about feeling the need to go on the internet and condescend other people to make me feel better about myself.
If I were you I’d think about going in for some professional help. Then after that, maybe brush up on your technical knowledge before you start throwing your opinions around
Edited by VeeFource on Wednesday 14th October 12:39
a 1.6 n/a is still a 1.6 n/a, no matter what it's fitted in! Enjoy your paranoid world of delusion, bye 
Mr2Mike said:
And the 'secret' to preventing that happening is not to drive it extra carefully. Driving like a granny is exactly what causes bore glazing and all the symptoms that go with it. Use the full range of RPM and engine loads, don't labour the engine and try not to sit at a constant RPM with light load on the engine for extended periods.
But does that mean constant rpm at medium load is ok? And what is an extended period? And most importantly, what are the mechanical reasons why? These are the questions I was hoping to answer which that report mentioned earlier goes a some way to explain, albeit not all of it.Unfortunately as is typical on PH a lot of other posters in this thread feel in a position to criticise the reasoning behind the thread despite not even having the knowledge to answer the question.
RoverP6B said:
Engine braking - what about with an auto gearbox? I'm new to autos, spent just one of my 40 years on the road without a clutch pedal, but I understood that with a torque converter you don't get engine braking?
I've wondered about this also as from what I've read is when they say varying the revs it means to get to the engine braking state as this is what sucks oil up past the pistons and cools things down. This helps with heat cycling and is an important part of the process. But as you say, you don't really get engine braking as such so you do have to wonder whether it's harder to run in an auto as well.The manuals should really state about completely lifting off the accelerator in gear in my opinion as a non-essential tip. As saying just to vary the revs could just mean to alternate between 65 & 70 on a motorway which is obviously not ideal. But then I appreciate us PHers that want the best for our engines are in a minority
Yuxi said:
Any need for running in went away years ago when manufacturers brought in plateau honing, its an additional step after the normal honing process. It leaves the bore in a condition like a well run in traditionally honed bore.
I'd love to believe that, but it doesn't explain why so many manufacturers give the same old guidelines for 600 odd miles?MJK 24 said:
Lotus still insist that engines are run in. Under 4k rpm for the first 1,000 miles then back to the dealer for an oil and filter change. They'll interrogate the ECU to make sure you adhered to the temporary rev limit.
It seems keeping it under 4k, to avoid labouring and maintaining steady revs are fairly standard across the board.DrDeAtH said:
Pretty much all major motor manufacturers dyno run the engines as they roll off the production line. They go through a breaking in process and load testing before being signed off as OK for installing.
The cars are only on there for about a minute to do a performance test, this ain't gonne break in an engine which again is why they advise to run the engine in.mogv8 said:
(snip)
- Try to avoid short journeys, the more 'cold starts' you have the more wear on a cold engine you will get. Lots of people have mentioned warming it up, but doing as few cold engine miles as possible is a better way to look at it. 1000 miles on say 4 cold starts has got to be better than 1000 miles on 400 cold starts.
(snip)
Also oddly enough more cold starts are actually better provided the engine gets up to temperature each time as the heat cycling helps eveything bed in much better.- Try to avoid short journeys, the more 'cold starts' you have the more wear on a cold engine you will get. Lots of people have mentioned warming it up, but doing as few cold engine miles as possible is a better way to look at it. 1000 miles on say 4 cold starts has got to be better than 1000 miles on 400 cold starts.
(snip)
I'm slightly baffled about the number of people claiming the best approach is gunning it from day 1 and that breaking in an engine is a thing of the past. They just don't seem to take on board that engineers give the advice in the manuals for a reason! And there's plenty of technical papers out there (like the one mentioned earlier) written by very clued up researchers that clearly state this is not a good idea.
My own reading into it has found that it's all about balance. Don't nail it as this causes the peaks of rough surfaces to overheat, flash the oil and causes glazing. Conversely nannying it means the rings aren't moved around enough
and pushed into the walls and the bores eventually polish the honing off out of round. The excessive blow-by during this time also causes glazing contributing to poor sealing.
So it's best to slowly build up the load from about 50% load through regular acceleration/decelleration over those 600 miles. And if you really want to be proper nerdy towards your engine then do it over 1500-2000 which is what most good sources state as the time to be properly run in.
Also don't change your oil too early. It's not as bad on modern engines as it used to be on older engines which were run in on mineral oil. But you don't want the engine to be too lubricated or it restricts the wear that needs to happen on the rings and bores. I intend to change my oil at 2k and it'll also be a good opportunity to put a magnetic sump plug in
Edited by VeeFource on Saturday 17th October 23:43
DrDeAtH said:
I spent 10 years working in Dagenham engine plant for Ford.
Every engine went into a dyno cell at the end of the assembly line. Each engine was hot tested for approx 15 mins. This included a warm up and break in cycle, load testing and a cool down cycle. This was not done on the car production line, but the engine manufacturing line.
The short test referred to previously is the vehicle validation test which is completed upon rolling of the vehicle production line - totally different.
Other examples of these test can be viewed on programmes like 'how its made' etc...
That's an interesting post! I guess it varies between manufacturers in which case. Wonder if Ford still write the usual running in advice in their manual or whether they still don't class that as run in yetEvery engine went into a dyno cell at the end of the assembly line. Each engine was hot tested for approx 15 mins. This included a warm up and break in cycle, load testing and a cool down cycle. This was not done on the car production line, but the engine manufacturing line.
The short test referred to previously is the vehicle validation test which is completed upon rolling of the vehicle production line - totally different.
Other examples of these test can be viewed on programmes like 'how its made' etc...
The Spruce goose said:
What is the car OP?
Please don't say it is a diesel?
It's a Suzuki Swift Sport, so a mass produced engine but with a fairly high output/litre for an n/a. Quite a light car too so a well run in engine is probably going to make more of a difference than in say a 316i I'd imagine.Please don't say it is a diesel?
I know it's not quick enough for most PHers, but I've done the fast car thing and now I'm more about having fun which it's already delivering in spades
That said it'll be good to make the most from what little it's got 
Sounds reasonable and is similar to what's described in this excellent article:
http://wiki.nasioc.com/wiki/Break-in_engine
Just reaffirms to me that those whom think this is a non-issue aren't a proper pistonhead
http://wiki.nasioc.com/wiki/Break-in_engine
Just reaffirms to me that those whom think this is a non-issue aren't a proper pistonhead
Pommygranite said:
I have a question - why is this one a keeper forever?
Funnily enough I got my Mum a mk1 and found it the most fun practical car I've ever driven (without spending a fortune anyways) and I've driven a lot of cars. So decided to get a mk2 (need cruise etc) but given it took me a year to find her a decent one and realising this will probably be the last n/a version you can get I decided to get a new one.Never thought I'd buy a new car but managed to get a good discount and am flippin loving it
Honestly can't see me getting rid of this thing so hoping to love it long time!mp3manager said:
Citation needed
I'm not saying it's the definitive answer, just that it seems to summarise most of the research I've done fairly well. Don't forget that even the experts don't know for sure as controlled testing of an engine for wear is inherently flawed in that you can only do so properly by stripped the thing and cutting it into pieces.Gassing Station | General Gassing | Top of Page | What's New | My Stuff