Do new vehicles still need a running in period?

My mate was telling me that his neighbour had a new campervan and couldn’t drive it “properly” until it had been run-in.

Is it still a thing?  I’ve not heard that saying for a long time

Salesbod will say no, every engine builder I know will say yes. You need to run an engine in to build up the lacquer on the cylinder bores, pistons and rings to properly seal everything and reduce metal on metal wear. likewise seals, gaskets and bearings all like to be polished/heat soaked a bit to do their job properly.

Doesn’t stop them getting ragged at the ports . I used to work next to a vehicle importers compound, post covid when the yards were almost empty they became like mini racing circuits.

Not seen for a few decades

I’ve never run in a new car (including the almost faultless 16 year old Mazda 3 that we recently sold) – from Fords and Mazdas to Mercedes, Volvos and Audis – and never had a single issue.

Yes.

All the sliding parts still need honing together without being overheated by the higher friction until they are.

And IIRC NIkasil (or one of the proprietary coatings) actually needs some of the components to be burnt off to leave the low friction surface.

Don’t know about cars but my motorbike handbook says don’t rag it until 600 miles – and don’t really rag it until 1000 miles.

The manual will tell you, some will say they need to be run in and how to do that, some will say no running in needed.

Many cars now have a delivery mode enabled at the factory to stop them being ragged stupid by load/unload crew. It prevents over-revving and limits gear selection. Part of the PDi process switches that off.

Anyway car manufacturers generally don’t give a monkeys about mechanical sympathy – it just has to make it to the end of the warranty period. Motorbike manufacturers are different as dead engine can kill a rider. From my KTM manuals:

You need to run an engine in to build up the lacquer on the cylinder bores, pistons and rings to properly seal everything

That doesn’t necessarily mean driving like granny though.  It has been proven that some engines (Yamaha 300hp v8 marine outboard engine is an excellent example) would “make oil”* if not driven like you stole it for short periods in the first few weeks of use.

* The new [soft] rings wouldn’t bed in properly unless driven hard.  After a little while the rings would harden up and the best ring-cylinder interface became unobtainable leading to unburnt fuel leaking down the sides of the piston, diluting the oil and actually increasing the fluid level in the sump.

I’ve followed the recommended run in period on all the new cars I’ve bought and not had an issue with any of them . I do the same with the stereo . At least 30 hours at lowish volume until it’s bedded itself in .

The only time a salesperson has mentioned it, was the Ford Commercial dealer when I have bought Transit Customs.

I went on a Porsche driving experience a while ago and was absolutely ragging it round the track . I was surprised to see it only had 800 miles on the clock , but the instructor seemed to think I the cars there had a special run in procedure rather than the recommended 1800 miles

There’s also the critical line “changing performance level” as that KTM manual puts it. You need to be alternating between open (but low) throttle and closed, as it’s the closed throttle that creates the vacuum that draws oil up through the piston rings to lubricate the bore.  Riding/Driving on the motorway at 1/3 throttle isn’t what they have in mind.

probably just as important to not rag an engine when it’s cold – that applies at all times but I personally would definitely be careful with a brand new one (although tbf I’m never going to buy brand new)

That doesn’t necessarily mean driving like granny though.  It has been proven that some engines (Yamaha 300hp v8 marine outboard engine is an excellent example) would “make oil”* if not driven like you stole it for short periods in the first few weeks of use.

Yes. exactly that. Varied use, building performance over time. High output engines can have specific requirements. My mate’s race k20s that he builds have a short life, so they get ragged from the off.

porsche might, might be bench run in. It’s what I’d expect them to do.

so I guess for a Ducato/Boxer it’s probably true then

Back in the 2000’s I was ordering fleet cars for a living (yaaaawn….) and one of the dealers we used on a regular basis gave me the ‘industry secret’ that it’s better to do the opposite of the breaking in period, and thrash the pants out of the engine…. It will open everything up better.

May or may not be true, and possibly not the best for the person who ends up buying the car with 100,000+ miles on the clock!

Some cars its a yes, some its a no.

If you are buying a Porsche 911 GT3 RS that definitely has a run in period.

That doesn’t necessarily mean driving like granny though.

This, really.

I’ve known people “run in” cars by driving around at 20mph in 5th.  That’s likely to do more harm than redlining it.

one of the dealers we used on a regular basis gave me the ‘industry secret’

Your logical fallacy is “false authority syndrome” 😁

I always take it easy with a new car, just be a bit mechanically sympathetic really. I tend not to over-rev it or let the engine labour for around 1000 miles and not tow with it for at least 1500 miles. I also try to vary the speed where I can rather than sit at a constant speed. Probably completely unnecessary as engines are produced so accurately these days but I still feel easier doing it.

when I picked up my current car (salary sacrifice lease EV), the handover chap said just to be careful and not floor it in the first 200 miles, something to do with big fat rwd wheels and 350bhp of instant EV torque which is prone to ripping newly fitted tyres off the rims .. 🙂

That’s the beauty of the EV , bed the tyres and brakes in and that’s you done . As your chap said , 200 miles should do it

I used to build engines and once they’re run up to operating temperature/the oil is above 80° then rag them through the gears/rev range as it helps to bed the rings into the bores.

Running in isn’t really a “thing” on modern engines.

I remember one of my Dad’s cars BITD (late 70s Audi 100, I think) recommending that it doesn’t go above 3000rpm for the first 1000 miles and then going for an oil and filter change.

I thrashed the balls off my yeti (1.4TSI 4×4) within hours of picking it up.
made sure it was fully warmed up and then went full on italian tune up on it.
In the 5 years we kept it for it never needed an oil top up, it was peachy.

I do remember watching a video on a brand new ferrari, where the customer was told not to be too gentle during the running in period or he would end up with a slow car that used oil.
I think ‘slow’ was a relative term in this context.

Having never had a new car to run in, I could not tell you….

I always run new engines in. I’ve built several, mainly for competition and even those I ran in for a few hours.

Competition engines are built for minimum friction. The bores are honed to perfection, the bearing surfaces corrected by hand having bolted up and checked the tight sports. The piston rings gapped a bit wider and the piston clearance increased slightly to account for high opperating temperatures. They turn over by hand until the cam belt or chain is added.

Rag a production engine from the off and any of the following could happen. A slight tight point on a bearing which would wear in during running in will get hot and suffer damage. The pistons rings could go tight in the bores at high load/temperature and suffer rapid wear. A cam follower may pick up until the cam has done a few revolutions and bedded in.

Given the performance of modern cars just driving along with the traffic without being a dick is running in enough, you won’t need much throttle or high revs to make perfectly normal progress unless you’re heading up an Alpine pass.

It’s good fun though, I just did a bit of a rebuild on a car and the new cams have completely different and incompatible break-in rules to the clutch. And if I’d put new pistons in it as originally planned the rings and bores would have a third set of different and incompatible break-in rules. But apparently when it’s an entire car that needs run in it’s all really simple.

The agressively profiled cams shouldn’t be spun too fast initially but that means no go at low revs so much clutch slipping. The pistons shouldn’t be either subject to high revs or high load which would raise temperatures so you’ll be trying to keep it just on the cam without too much clutch slipping.

Something like that?

I thrashed the balls off my yeti (1.4TSI 4×4) within hours of picking it up.

I did the same to my new car I picked up 2 months ago, got to temperature on the drive out of Dumfries and up the hill (A75) I pressed the red super sport button on the steering wheel and took it to the rev limit…………..it was a 1.5 MG HS Trophy so absolutely nothing happened at all apart from the dash turned red – a contender for utterly pointless button of the year award in the shittest car of the year.

😉

@edukator, Pretty much- I think realistically to do it as they say would mean doing some of it on a dyno like I did with the bike. Course, it’s all full of hedging and dealing with human psychology, and the 2 different cams I looked at from different manufacturers had wildly different break in rules anyway, so you just lean towards convenience/practicality in the end.

And then it had a coolant leak so it had to sit idling for ages anyway while I sorted that 😛

The more I think about this,

I haven’t built engines or worked for McLaren or what have you.  But surely any “breaking in” period would just mean “don’t drive like you stole it” for a bit”?

It feels to me like “established wisdom” that your grandad told you when he bought his Austin Allegro.  If it were truly necessary it’d be done whilst still at the factory.  No?

When did you last hear “well, it wasn’t broken in properly” as reason for failure?  Ever?  It’s a 1L 3-pot TSI, not a horse.

my mitsubuishi said that i should drive it in low range / off road till 3k miles were on the clock – i suspect that this was essentially running in

Just drive it normally then take it back for an oil change at the recommended mileage.

FB-ATB
Full Member
Doesn’t stop them getting ragged at the ports

I used to work for Sea King in the late 90’s on Sheppey.

Apart from all the crashes I saw on very spendy motors (“cheap” ones too )I was also very surprised at the huge body shop they had to repair them.

Ive never been able to afford a new car but at least I now know that there is no such thing as a new car anyway!

I’ve been things you people wouldn’t believe. 😉

I used to work for Sea King in the late 90’s on Sheppey.

I was working at Queenborough!

I’ve built a couple of aircooled VW engines years ago, the break in for the cam used to be 20mins at 2000revs I think. Nothing scarier than roughly setting the timing & isle screws, starting up your freshly built engine, pulling & locking the throttle cable and starting a timer. Hoping you’ve done it right and it doesn’t overheat 😬

it was then a fresh oil change and a few hundred miles of running in, I seem to remember it involved plenty of engine breaking, which was to help the piston rings?

Many cars now have a delivery mode enabled at the factory to stop them being ragged stupid by load/unload crew. It prevents over-revving and limits gear selection. Part of the PDi process switches that off.

That’s been a thing since i started in the business 20+ years ago. We’ve got steadily more aggressive with how much the cars are restricted, as the crews have got steadily more destructive. Speed limits, shift delays, autobraking, deactivated AC, deactivated infotainment, accelerator pedal limit, torque and power limits.

They still break and crash a small percentage of cars every year.

Most modern, stock, engines don’t need “breaking in” as such. They haven’t for years, most of the “drive sensibly for x000 km” stuff is to calibrate sensors/injectors/control modules and make sure any manufacturing gunk that’s been missed gets washed into a sump or filter somewhere. Make sure the pads and discs are good, nothings been left loose. Doesn’t seem to help some manufacturers though!

If it were truly necessary it’d be done whilst still at the factory.  No?

That was in the olden days, when production volumes were relatively low, engines had relatively low specific power outputs and simple connections to the outside world. Couple of places i’ve worked/visited still have a Run In Room at the end of the engine production line, along with the carb balancing shop and the float/needle tuning station. These days they’d only have about 60 seconds per engine, and most of the engines will (potentially) be shipped from the engine plant, several 100km to be married to an exhaust system, transmission and car, so can’t really be run in with fuel/coolant/coolers/oil cooler due to then needing cleaning afterwards and all the faffing around to get it connected to a rig. So they moved the responsibility to the owner. Hence running in going in the manual.

Now we’re much better at making engines, better materials, better heat treatments, better machining, so once you’re started it, run the oil round the block and up to temperature, run through all the gears a couple of times, as long as nothings failed, you should be good to go in 99% of cars.