How to treat a "brand new" car, and tyre query

[Workaholic]

Nope its not how to clean it but more of a mechanic thing.

My dad mentioned to my uncle who had just bought a brand new car NOT take it on the motorway yet until you have done 100+ miles or so. Supposedly this helps maintaining the engine etc but what I want to know is how?

Surely if you go on the motorways at the start (the engine's fuel consumption should default to the higher one - urban roads... or am I thinking of something irrelevant...)


Secondly why do NEW spare tyres have a MAX recommended speed limit of 50mph - what happens if you need to change the tyre on the motorways, do you:

1) drive at 40ish on the hard shoulder till you get to the next junction
2) Drive in the inside lane and hope no articulared lorries decide to nudge you forward faster? (at 50mph!)
3) Wait for AA/RAC to tow you away?

[fat jez]

Secondly why do NEW spare tyres have a MAX recommended speed limit of 50mph - what happens if you need to change the tyre on the motorways, do you:

Usually they are those daft space saver tyres, which aren't rated for 70MPH.

Cheers,
Stephen

[staffsMike]

You drive on the inside lane and let all the lorries pass you lol

Running in engines these days is normally not so much of a problem but I still do it.

Try to do 1000 miles with the rev's fairly low, say lower than 4000 RPM (should tell you in the manual)

Also vary the miles between town, country lanes ,motorways etc.. After the first 1000mile's start giving it the beans if thats how you drive

Most important thing though is not so much keeping the revs low but not letting the engine labour. So don't stick it 5th doing 30mph etc.. for a while

[Shad]

You should try to avoid keeping the revs at the same point for any length of time. While you don't want to thrash the engine in its early life, you need to keep the revs and load varied so everything beds in properly. Try and keep within the first two thirds of the rev range too and don't labour the engine too much, e.g. accelerating in 4th gear at 30mph.

So driving on a motorway may not be a great idea because you would sit at 70mph in 5th keeping the revs the same

[Lowe]

There's an argument out there that says that you should be using lots of load and fairly high revs to help seat the rings properly. They say thrashed cars give better performance heh! I'll try digging out a link later

[Rishi]

There's an argument out there that says that you should be using lots of load and fairly high revs to help seat the rings properly. They say thrashed cars give better performance heh! I'll try digging out a link later

Yep, I have heard this too.

Also true for some older cars, my friends E30 M3 needs to be ragged quite often to keep it running fine.

Ideally, you probably wanna drive it low revs intially then put it through its paces, cos lets face it one day your gonna put your foot down.

[chriswood_7]

Ive heard of taking it easy over the first few thousand miles, to ensure that all of the seals etc are well bedded, and obviously so you dont stress the components at the early stages of there life-cycle. But as far as avoiding motorways etc, I really cant see the real point of this at all. Cars are meant to be driven at the end of the day. A normal everyday car is not going to break if you take it on a motorway when its brand new.

[Zak33]

it IS true....HARD RUN IN
http://www.mototuneusa.com/break_in_secrets.htm

I have now had 6 Saab Trubo Diesels and the 4 I have thrashed from day one use no oil...the 2 that I was gentle on used oil.

Get it warm....and then give it hell

[schmunk]

it IS true....HARD RUN IN
http://www.mototuneusa.com/break_in_secrets.htm

I have now had 6 Saab Trubo Diesels and the 4 I have thrashed from day one use no oil...the 2 that I was gentle on used oil.

Get it warm....and then give it hell

That's a particular issue for VAG diesels too, if you baby them too much the valve seats don't bed in and that gulp down oil. You need to rev them high frequently in the first few thousand miles. I understand it even says this in the handbook.

[Fox]

I had a brand new 320i which I put about 1-1.5k miles on from 6 miles.

I was really good to it for the first 500 miles, and then drove it normally after that.

[staffsMike]

Diesels don't deserve to be drive kindly anyway so yes..thrash away if it's diesel..

running in cars comes from the good old days where things needed to bed in slowly else they would break before the first oil change.. which would be done at the end of the bedding in period.

It still exists in modern cars though. The 2.0 litre Impreza turbo's for example. They are delivered with very thin oil to bed the engine in which is why the first service is at 1000miles.

[Zak33]

the reason HARD RUN IN.... or HARD BREAK IN, seems to work is thus:

When a car is new, the piston rings are relatively loose. The compression in the cylinders is lower than it will be after a few thuosand miles.

It seems that IF you give it a bag fullof beans from day one, and give it a hard drive, the compression on the top of the clinder, pushes down the bores and forces the piston rings the only way they can go....OUTWARDS. The result is a set of piston rings that sits out and fits the bore better.

Now, for 17 years I've been driving brand new cars and I must have had literally hundreds. In hind site, the ones that I drove hard, and then sold, and which I took back in P/X years later, were always mecanically fine.

The greatest example is a Nova 1.4 back on H reg, which was a twin choke carb unit, with no rev limiter.

That car had it's balls bashed from day one...and I sold it to a mate who had it for nearly 7 years, and she never had any oil use from it, AND it was the fastest damn 1.4 I ever drove.

[Vimeous]

The only new cars I've ever driven have been pool cars and by law they get a spanking.

I apply a less scientific approach. Leave anything unused long enough and it deteriorates, even more so if exposed to 'the elements'. It can apply to anything but suspension joints and bushes are an obvious one. Also I reckon tyres will perish much later if used properly than if left to stand.

It doesn't mean you should thrash a car everywhere you go but it does it good to be used to its full potential once in a while.

At the end of the day I guess your money either ends up in repairs (when unused stuff fails) or running costs (when used stuff wears out!), it costs regardless