Do modern engines need running in?
Discussion
Glosphil said:
UpThe said:
No, it’s leased, so who cares.
I think this if buying an ex-rental car. When it was new do renters treat it as a new car shoulbe treated? I doubt it. dEspecially that Octavia down the m40 at 3am, Vmax the whole 90 miles from Brum to the m25
Glosphil said:
I think this if buying an ex-rental car. When it was new do renters treat it as a new car shoulbe treated? I doubt it. d
My previous car (Vectra 3.2 GSi) was ex rental. Bought it 6 months old with 16K on it, went on to do 175K just needed 1 new battery and obvious consumables. Traded it in after 14 years.The only modern cars i'd "run in" are those that have a specific run in period with an oil change afterwards, typically at around 1000 to 1500 miles. This is because they will be initally filled with a lower performance oil, a deliberately low lubricity oil in fact. This means that at high oil temperatures and high engine metal temps (under heavy load at high rpm) that oil will not be as good as the 'correct' oil. If there is no run-in service, that means you car has the std oil in it straight away, so give it say 100 miles of increasing load from brand new to bed the rings, then go ahead an fully beat on it :-)
Car_Nut said:
rockin said:
Do they need running-in? No
Should you rag them from new? No
Drive sensibly for the first 1,000 miles and all will be fine.
The third bullet point contradicts the first two!Should you rag them from new? No
Drive sensibly for the first 1,000 miles and all will be fine.
So what did the old-fashioned concept involve?
- X rpm for the first 500 miles
- 500 mile oil change
- Y rpm for the next 500 miles
- Z rpm for the next 1,000 miles
- etc
Wacky Racer said:
What a load of cobblers.
Yes, you don't have to "run in" a new car at 40mph like you used to do in the 1960's, but it's common sense to drive sensibly for the first few hundred miles, engines cost thousands of pounds.
Why is it 'a load of cobblers'? Engines costs faarsands of paaands... lol. What do you think a warranty's for? What do you think will happen in the first few hundred miles if you didn't take it easy? Will the engine seize up as if by magic? I can't even remember the last time I heard of someone having to recondition a modern engine (by modern, I mean something produced within the last 30 years), not unless that engine was highly strung, poorly maintained, or poorly designed.Yes, you don't have to "run in" a new car at 40mph like you used to do in the 1960's, but it's common sense to drive sensibly for the first few hundred miles, engines cost thousands of pounds.
If it was really a problem for manufacturers, do you not think they would really push for the running in thing? It's only enthusiasts that even know what running in is. Go and mention running in to any layman and you'll bet met with a blank stare.
Max_Torque said:
The only modern cars i'd "run in" are those that have a specific run in period with an oil change afterwards, typically at around 1000 to 1500 miles. This is because they will be initally filled with a lower performance oil, a deliberately low lubricity oil in fact. This means that at high oil temperatures and high engine metal temps (under heavy load at high rpm) that oil will not be as good as the 'correct' oil. If there is no run-in service, that means you car has the std oil in it straight away, so give it say 100 miles of increasing load from brand new to bed the rings, then go ahead an fully beat on it :-)
Can you explain the lower performance oil with lower lubricity a bit clearer for me please ,also name which modern cars you’ve ran in and changed oil as per above ?Buster73 said:
Max_Torque said:
The only modern cars i'd "run in" are those that have a specific run in period with an oil change afterwards, typically at around 1000 to 1500 miles. This is because they will be initally filled with a lower performance oil, a deliberately low lubricity oil in fact. This means that at high oil temperatures and high engine metal temps (under heavy load at high rpm) that oil will not be as good as the 'correct' oil. If there is no run-in service, that means you car has the std oil in it straight away, so give it say 100 miles of increasing load from brand new to bed the rings, then go ahead an fully beat on it :-)
Can you explain the lower performance oil with lower lubricity a bit clearer for me please ,also name which modern cars you’ve ran in and changed oil as per above ?Used to always be the consensus, amongst the race engine builders I spoke to, that a new engine be build and run for 150ish miles on old non-synthetic mineral oil, before being dropped and replaced with a modern fully synthetic as it was designed for. Something about the mineral oil, not sure what exactly, helped components to bed in better - the implication was that non-synthetic held any wear particles better so almost acted as a sort of flush.
Modern engines in mass produced cars are filled with the same oil you'll fill it with in service, and typically have an interval of 10,000 miles - this isn't really derived from optimising run-in, more that manufacturers have deemed the risk acceptable to not change the oil, and therefore have a happier customer that doesn't need to come back to the dealer as often as a result. However, I suspect this is a double edged sword, as that first visit probably resulted in a lot of "oh whilst I'm here, can you just..." requests, which therefore wouldn't get picked up a quality issue (i.e. a dedicated dealer visit) so probably increased (adversely) the quality metrics.
I always get corrected by internet warriors, mainly on BMW forums (as I own an M3) by saying that even big end/rod end bearings have a degree of running-in period, it's not just the piston rings to bore as everyone expects, but I take it on the chin, my day job is designing and validating engines, but they know far better of course. Now bearings won't release any material as it's nowhere like as severe an interface as a piston ring seating in a bore, but it's a fallacy to say they don't run or bed themselves in.
I find it interesting that the biggest risk for modern oils is them becoming too acidic, as the interval increases exponentially, the oil breaks down in heat cycles, affecting not it's lubricity but it's overall acidity (TAN number), and affecting components in that way. Modern synthetics are pretty impressive in terms of maintaining their attributes (lubricity or friction) over such a wide range of temperatures, especially given that engines are running down to 0w-30 or 0w-20 in places. Tribology is a fascinating and in my opinion, dark art.
Edit I didn't even talk about running in, in my opinion, 1000 miles of varied load (that includes high load but not high speed) rather than just sitting on the motorway with cruise set for hours is best - but engines will loosen up, in my experience over about 6,000 miles or 10k KM
Modern engines in mass produced cars are filled with the same oil you'll fill it with in service, and typically have an interval of 10,000 miles - this isn't really derived from optimising run-in, more that manufacturers have deemed the risk acceptable to not change the oil, and therefore have a happier customer that doesn't need to come back to the dealer as often as a result. However, I suspect this is a double edged sword, as that first visit probably resulted in a lot of "oh whilst I'm here, can you just..." requests, which therefore wouldn't get picked up a quality issue (i.e. a dedicated dealer visit) so probably increased (adversely) the quality metrics.
I always get corrected by internet warriors, mainly on BMW forums (as I own an M3) by saying that even big end/rod end bearings have a degree of running-in period, it's not just the piston rings to bore as everyone expects, but I take it on the chin, my day job is designing and validating engines, but they know far better of course. Now bearings won't release any material as it's nowhere like as severe an interface as a piston ring seating in a bore, but it's a fallacy to say they don't run or bed themselves in.
I find it interesting that the biggest risk for modern oils is them becoming too acidic, as the interval increases exponentially, the oil breaks down in heat cycles, affecting not it's lubricity but it's overall acidity (TAN number), and affecting components in that way. Modern synthetics are pretty impressive in terms of maintaining their attributes (lubricity or friction) over such a wide range of temperatures, especially given that engines are running down to 0w-30 or 0w-20 in places. Tribology is a fascinating and in my opinion, dark art.
Edit I didn't even talk about running in, in my opinion, 1000 miles of varied load (that includes high load but not high speed) rather than just sitting on the motorway with cruise set for hours is best - but engines will loosen up, in my experience over about 6,000 miles or 10k KM
Edited by Mr.Jimbo on Wednesday 22 July 10:53
I am always fascinated by the idea of "running in" an engine. What I would love to know is what people actually think is going on inside the engine that is changing.
In ye olden days of wonky tolerances on all manner of parts, then I can completely understand it, but wearing away of bits so they fit together nicely would mean it would be a good idea to drop the oil and replace, much like we used to do.
However, with modern engines having far better tolerances and the first service sometimes being over a year after delivery, is it really an issue? If so, surely there should still be an oil drop and filter change after a shortish period?
All components "loosen up" over time on a new car, from suspension bushes and dampers, to the engine internals, but over years of having new cars regularly, I can't say I have detected any hugely noticeable changes in power out-put or consumption between the start and the end, certainly nothing more noticeable than the mood I am in and how heavy my right foot feels!
Given that straight after manufacture, a car generally gets shoved onto a dyno and redlined through the gears to ensure it meets the spec, surely this suggests the idea of gently breaking an engine in, is somewhat bolting the stable door after the horse has bolted!
In ye olden days of wonky tolerances on all manner of parts, then I can completely understand it, but wearing away of bits so they fit together nicely would mean it would be a good idea to drop the oil and replace, much like we used to do.
However, with modern engines having far better tolerances and the first service sometimes being over a year after delivery, is it really an issue? If so, surely there should still be an oil drop and filter change after a shortish period?
All components "loosen up" over time on a new car, from suspension bushes and dampers, to the engine internals, but over years of having new cars regularly, I can't say I have detected any hugely noticeable changes in power out-put or consumption between the start and the end, certainly nothing more noticeable than the mood I am in and how heavy my right foot feels!
Given that straight after manufacture, a car generally gets shoved onto a dyno and redlined through the gears to ensure it meets the spec, surely this suggests the idea of gently breaking an engine in, is somewhat bolting the stable door after the horse has bolted!
IforB said:
I am always fascinated by the idea of "running in" an engine. What I would love to know is what people actually think is going on inside the engine that is changing.
In ye olden days of wonky tolerances on all manner of parts, then I can completely understand it, but wearing away of bits so they fit together nicely would mean it would be a good idea to drop the oil and replace, much like we used to do.
However, with modern engines having far better tolerances and the first service sometimes being over a year after delivery, is it really an issue? If so, surely there should still be an oil drop and filter change after a shortish period?
All components "loosen up" over time on a new car, from suspension bushes and dampers, to the engine internals, but over years of having new cars regularly, I can't say I have detected any hugely noticeable changes in power out-put or consumption between the start and the end, certainly nothing more noticeable than the mood I am in and how heavy my right foot feels!
Given that straight after manufacture, a car generally gets shoved onto a dyno and redlined through the gears to ensure it meets the spec, surely this suggests the idea of gently breaking an engine in, is somewhat bolting the stable door after the horse has bolted!
They don't, or rather all OEMs I've worked with certainly don't certify power on every car they produce. It will have a short rolling road test but this is to check things like gearbox operation, basic engine operation etc. In ye olden days of wonky tolerances on all manner of parts, then I can completely understand it, but wearing away of bits so they fit together nicely would mean it would be a good idea to drop the oil and replace, much like we used to do.
However, with modern engines having far better tolerances and the first service sometimes being over a year after delivery, is it really an issue? If so, surely there should still be an oil drop and filter change after a shortish period?
All components "loosen up" over time on a new car, from suspension bushes and dampers, to the engine internals, but over years of having new cars regularly, I can't say I have detected any hugely noticeable changes in power out-put or consumption between the start and the end, certainly nothing more noticeable than the mood I am in and how heavy my right foot feels!
Given that straight after manufacture, a car generally gets shoved onto a dyno and redlined through the gears to ensure it meets the spec, surely this suggests the idea of gently breaking an engine in, is somewhat bolting the stable door after the horse has bolted!
Manufacturers typically have an engine dyno setup with the air intake and exhaust from said vehicle, they'll then pull a random engine every so many months, and do a witnessed Conformity of Performance test on it, to ensure it's within the mandated 5% plus/minus tolerance for power certification. It's a myth (imo) that cars are dyno'd before they leave the factory. Rolling road, yes, but as said this is more a holistic "is everything working correctly" test - ECU flashes, different softwares for different markets etc.
My thinking is that most people get in the car and drive it, generally bouncing it off the rev limiter in the first seconds doesnt happen as we arent all excitable chimpanzees given a car for the first time.
Common sense, noise, manners, traffic,speed limits and whatever kick in before anyone is actually ragging their car senseless.
Once oil has circulated, even if its up to temp, modern cars will cope with being revved to the redline without dying.
It generally isnt Pistons, cams, valves, crank and whatever that kills a car after however many years, its the stuff bolted to the engine for emissions, wiring, ecu, turbos, breathers, cats, injectors etc etc failing, generally being old, tired and too expensive to get right vs market value or a crash that kills them. Oh, and design defects like cam chains snapping which can happen despite diligent maintenance and been treated gently.
So many cars go to the scrappers with perfectly serviceable engines, many dont ever get removed as no call for them if they were any good in the first place.
I have mechanical sympathy but I am not waiting 20 minutes for water temperatures, give it a couple of minutes and then feel free to give it some stick, service it to the schedule and hope for the best.
I bet I couldn't kill a new car in a year of actively trying by treating it like s
t, as long as it had oil in it it wont die, and its amazing how long some will go even without oil based on YT videos.
I tried to kill a hateful shed of a Metro GTI, bounced it off the limiter, buzzed it on downchanges, no warmup allowed, the fan wasnt kicking in so it got very hot in traffic, several months or trying to break it and I swear the little fker just got faster, it was rapid for what it was. Must be the only person that didnt manage to kill a K series, maybe that was the key, treat em mean, keep em keen ?
Common sense, noise, manners, traffic,speed limits and whatever kick in before anyone is actually ragging their car senseless.
Once oil has circulated, even if its up to temp, modern cars will cope with being revved to the redline without dying.
It generally isnt Pistons, cams, valves, crank and whatever that kills a car after however many years, its the stuff bolted to the engine for emissions, wiring, ecu, turbos, breathers, cats, injectors etc etc failing, generally being old, tired and too expensive to get right vs market value or a crash that kills them. Oh, and design defects like cam chains snapping which can happen despite diligent maintenance and been treated gently.
So many cars go to the scrappers with perfectly serviceable engines, many dont ever get removed as no call for them if they were any good in the first place.
I have mechanical sympathy but I am not waiting 20 minutes for water temperatures, give it a couple of minutes and then feel free to give it some stick, service it to the schedule and hope for the best.
I bet I couldn't kill a new car in a year of actively trying by treating it like s
t, as long as it had oil in it it wont die, and its amazing how long some will go even without oil based on YT videos. I tried to kill a hateful shed of a Metro GTI, bounced it off the limiter, buzzed it on downchanges, no warmup allowed, the fan wasnt kicking in so it got very hot in traffic, several months or trying to break it and I swear the little f
ker just got faster, it was rapid for what it was. Must be the only person that didnt manage to kill a K series, maybe that was the key, treat em mean, keep em keen ?Mr.Jimbo said:
Used to always be the consensus, amongst the race engine builders I spoke to, that a new engine be build and run for 150ish miles on old non-synthetic mineral oil, before being dropped and replaced with a modern fully synthetic as it was designed for. Something about the mineral oil, not sure what exactly, helped components to bed in better - the implication was that non-synthetic held any wear particles better so almost acted as a sort of flush.
Modern engines in mass produced cars are filled with the same oil you'll fill it with in service, and typically have an interval of 10,000 miles - this isn't really derived from optimising run-in, more that manufacturers have deemed the risk acceptable to not change the oil, and therefore have a happier customer that doesn't need to come back to the dealer as often as a result. However, I suspect this is a double edged sword, as that first visit probably resulted in a lot of "oh whilst I'm here, can you just..." requests, which therefore wouldn't get picked up a quality issue (i.e. a dedicated dealer visit) so probably increased (adversely) the quality metrics.
I always get corrected by internet warriors, mainly on BMW forums (as I own an M3) by saying that even big end/rod end bearings have a degree of running-in period, it's not just the piston rings to bore as everyone expects, but I take it on the chin, my day job is designing and validating engines, but they know far better of course. Now bearings won't release any material as it's nowhere like as severe an interface as a piston ring seating in a bore, but it's a fallacy to say they don't run or bed themselves in.
I find it interesting that the biggest risk for modern oils is them becoming too acidic, as the interval increases exponentially, the oil breaks down in heat cycles, affecting not it's lubricity but it's overall acidity (TAN number), and affecting components in that way. Modern synthetics are pretty impressive in terms of maintaining their attributes (lubricity or friction) over such a wide range of temperatures, especially given that engines are running down to 0w-30 or 0w-20 in places. Tribology is a fascinating and in my opinion, dark art.
Edit I didn't even talk about running in, in my opinion, 1000 miles of varied load (that includes high load but not high speed) rather than just sitting on the motorway with cruise set for hours is best - but engines will loosen up, in my experience over about 6,000 miles or 10k KM
Very true.Modern engines in mass produced cars are filled with the same oil you'll fill it with in service, and typically have an interval of 10,000 miles - this isn't really derived from optimising run-in, more that manufacturers have deemed the risk acceptable to not change the oil, and therefore have a happier customer that doesn't need to come back to the dealer as often as a result. However, I suspect this is a double edged sword, as that first visit probably resulted in a lot of "oh whilst I'm here, can you just..." requests, which therefore wouldn't get picked up a quality issue (i.e. a dedicated dealer visit) so probably increased (adversely) the quality metrics.
I always get corrected by internet warriors, mainly on BMW forums (as I own an M3) by saying that even big end/rod end bearings have a degree of running-in period, it's not just the piston rings to bore as everyone expects, but I take it on the chin, my day job is designing and validating engines, but they know far better of course. Now bearings won't release any material as it's nowhere like as severe an interface as a piston ring seating in a bore, but it's a fallacy to say they don't run or bed themselves in.
I find it interesting that the biggest risk for modern oils is them becoming too acidic, as the interval increases exponentially, the oil breaks down in heat cycles, affecting not it's lubricity but it's overall acidity (TAN number), and affecting components in that way. Modern synthetics are pretty impressive in terms of maintaining their attributes (lubricity or friction) over such a wide range of temperatures, especially given that engines are running down to 0w-30 or 0w-20 in places. Tribology is a fascinating and in my opinion, dark art.
Edit I didn't even talk about running in, in my opinion, 1000 miles of varied load (that includes high load but not high speed) rather than just sitting on the motorway with cruise set for hours is best - but engines will loosen up, in my experience over about 6,000 miles or 10k KM
Edited by Mr.Jimbo on Wednesday 22 July 10:53
Oxidisation (which shows up as acidicy that you mention) and wear protection was an issue with some of the early/true synthetic oils (Ester/POA) requiring strong additives such as high doses of ZDDP, very costly for a short life oil and still not as good particle suspension (note HGV, with superlong extended drain intervals skipped over Ester/PAO for this reason) as mineral.
Most oils now use hydro-cracked and/or GTL "synthetic" refined earth oil/gas (I put in quotes as is synthetic only by a legality, not scientific definition) as their main base oil, which are generally better than mineral for holding particles in suspension, so a separate running oil is not needed anymore where a synthetic oil is the normal fill.
With engines being built to far closer tolerances, cleaner environments, better understanding/prediction of how new engines bed-in, there is less need for a running-in oil change and manufacturers take a calculated cost vs reliability vs life decision/compromise when decided a running-in process (or not at all).
Additive packs have advanced in the past few decades, and as you mention the Anti-Wear additives work from much lower temperatures than they used to - which when firing up a new engine from cold is the most important time to get the running-in process right, as metals/coatings shape/bed/harden most significantly with the first heating cycle, I assume this is a factor when designing an engine.
I was told (I think by Millers) that running in oil was the same mineral base as their regular oil, but with less/no additives.
I've read stories that some production engines are pre-run before being installed as a quality control (but also acts as a running in stage) but never looked into.
I remember having specific instructions for running-in fast-road and rally cams I used to fit to some of my cars many decades ago, so ensure no excess pressure on the tips ( before surfaces harden - I think).
Edited by NGRhodes on Wednesday 22 July 12:31
Mr.Jimbo said:
IforB said:
I am always fascinated by the idea of "running in" an engine. What I would love to know is what people actually think is going on inside the engine that is changing.
In ye olden days of wonky tolerances on all manner of parts, then I can completely understand it, but wearing away of bits so they fit together nicely would mean it would be a good idea to drop the oil and replace, much like we used to do.
However, with modern engines having far better tolerances and the first service sometimes being over a year after delivery, is it really an issue? If so, surely there should still be an oil drop and filter change after a shortish period?
All components "loosen up" over time on a new car, from suspension bushes and dampers, to the engine internals, but over years of having new cars regularly, I can't say I have detected any hugely noticeable changes in power out-put or consumption between the start and the end, certainly nothing more noticeable than the mood I am in and how heavy my right foot feels!
Given that straight after manufacture, a car generally gets shoved onto a dyno and redlined through the gears to ensure it meets the spec, surely this suggests the idea of gently breaking an engine in, is somewhat bolting the stable door after the horse has bolted!
They don't, or rather all OEMs I've worked with certainly don't certify power on every car they produce. It will have a short rolling road test but this is to check things like gearbox operation, basic engine operation etc. In ye olden days of wonky tolerances on all manner of parts, then I can completely understand it, but wearing away of bits so they fit together nicely would mean it would be a good idea to drop the oil and replace, much like we used to do.
However, with modern engines having far better tolerances and the first service sometimes being over a year after delivery, is it really an issue? If so, surely there should still be an oil drop and filter change after a shortish period?
All components "loosen up" over time on a new car, from suspension bushes and dampers, to the engine internals, but over years of having new cars regularly, I can't say I have detected any hugely noticeable changes in power out-put or consumption between the start and the end, certainly nothing more noticeable than the mood I am in and how heavy my right foot feels!
Given that straight after manufacture, a car generally gets shoved onto a dyno and redlined through the gears to ensure it meets the spec, surely this suggests the idea of gently breaking an engine in, is somewhat bolting the stable door after the horse has bolted!
Manufacturers typically have an engine dyno setup with the air intake and exhaust from said vehicle, they'll then pull a random engine every so many months, and do a witnessed Conformity of Performance test on it, to ensure it's within the mandated 5% plus/minus tolerance for power certification. It's a myth (imo) that cars are dyno'd before they leave the factory. Rolling road, yes, but as said this is more a holistic "is everything working correctly" test - ECU flashes, different softwares for different markets etc.
That is what I mean by does it really matter? If the manufacturer have given the car a good thrashing (for whatever reason) as part of the build process, then what else is gentle running in going to do?
Are heat cycles important for example? Or is it just the bedding in of bearings and mating surfaces etc that is important? If so, how much really goes on?
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