Sustained high speed damaging?

Don't agree, engines prefer sustained loads, blatting up and down a country lane in all sort of gears with the engine revs going from 3k to 7k is much harder on a car than sitting at 130mph doing 5.5k rpm.

Provided you have tyres rated for in excess of the speed you will be doing, i.e. mine are rated at 184mph (iirc) then i can't see too much of a problem doing high speed for a long period of time, the tyres will probably be cooler than being driven hard down a country lane, in which they have sideways force and braking heat to deal with.
 
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Firestar_3x said:
Don't agree, engines prefer sustained loads, blatting up and down a country lane in all sort of gears with the engine revs going from 3k to 7k is much harder on a car than sitting at 130mph doing 5.5k rpm.
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Again, from the OP i didn't think we were comparing "blasting the car down a country lane" VS high speed driving, i thought we were comparing normal driving VS high speed driving.

It's often said that a sustained load is better for a vehicle, of which i don't dispute, but 130mph with high engine loads and mid-high RPM's will be doing additional wear to the engine. A lot of this wear will come from the heat being produced and I imagine oil shear is an issue when it gets too hot. A lot of it will come from components having to just work harder.

Firestar_3x said:
Provided you have tyres rated for in excess of the speed you will be doing, i.e. mine are rated at 184mph (iirc) then i can't see too much of a problem doing high speed for a long period of time, the tyres will probably be cooler than being driven hard down a country lane, in which they have sideways force and braking heat to deal with.
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IIRC the speed quoted is what the tyre should be able to do for a period of 20 minutes before total failure. Obviously, this is in a test environment. In the real world, tyres have been through all sorts of different environments and some may be weaker than others - after all people have spontaneous blowouts at 70mph.

Just because your tyre is rated up to 186mph does not mean that it is not going to fail below that, especially with sustained high speed driving. Tyre pressures go up, degradation increases and the risk of damage to the tyre from the road surface is increased. Tyre valve stems even get hot and bend/crack at high speeds with the centrifugal force.

I'll say again, the heat in tyres at high speed is significant and absolutely comparable to B road driving, if not more. This is not counting the risk of damage to the tyre from the road surface or debris on the road.
 
Sustained high load high rpm kills engines, cooling and lubrication is often inadequate for prolonged abuse. Saying that, it's mainly high output turbo stuff that goes bang.
Driven tyres are going to heat up fast, it might be a constant speed but you are pushing the max engine output through them constantly to push it through the air.
 
I did some 100+ for 25-odd miles in my old Jaguar, with sustained 140-odd mph at points and lots of fast cornering and hard acceleration in between, no problems. Depends on the car and what it was built to do, really - i.e. small hatchback with eco engine, rapid death. Big exec saloon with 155mph+ top end, probably not going to have much of an issue.

Myriad variables though.

Tyres were completely spent after that though - corners you could take at 80mph couldn't be taken at any more than 50mph all of a sudden, it'd just spin out. All the adhesion had just gone. They were pretty gnarly to start with anyway, admittedly...
 
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Gaygle said:
It's often said that a sustained load is better for a vehicle, of which i don't dispute, but 130mph with high engine loads and mid-high RPM's will be doing additional wear to the engine. A lot of this wear will come from the heat being produced and I imagine oil shear is an issue when it gets too hot. A lot of it will come from components having to just work harder.
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Whilst this is obviously true is this wear material enough to make any difference to the expected life of the engine?

After all, is, say, a 545i sitting at 130mph really working any harder than a Fiesta 1.25 sitting at 80, which thousands of them do daily in the UK without grenading themselves?
 
Mechanically a high speed run shouldn't do much if any in the way of damage unless there is something wrong with the car or its not been looked after.

Bodywork on the other hand can be damaged, stone chips, panels bending due to the air hitting them harder than they are designed for and sometime even bumpers (especially rear) ripping off completely.
 
I think the word 'damaging' is where this gets difficult. Doing anything with a car ultimately damages it a little bit. It's called wear.

I'm sure that driving a car at 100% throttle will wear out some components faster than if it was at a lower output.
 
Something Else said:
Mechanically a high speed run shouldn't do much if any in the way of damage unless there is something wrong with the car or its not been looked after.

Bodywork on the other hand can be damaged, stone chips, panels bending due to the air hitting them harder than they are designed for and sometime even bumpers (especially rear) ripping off completely.
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I remember regularly seeing mondeos with the rear bumper flapping at motorway speeds, was an old model though, mk1 or mk2 or something like that.
 
There is no higher duty load on your motor than Vmax, around peak power output continous for extended periods. If your car is in good condition it will not die, it will cause more wear than, for example; idle, but shouldn't be anything to worry about.

If your car is not in good condition, for example it spent most of its life running on the same oil, has slack valve stem seals, has loads of blowby and is consuming a litre of oil every 1,000 miles and as a result is over-compressing... Vmax probably will kill it.

125 is the last thing my 146 ever did.
 
From my experience motorways are pretty easy on engine life. It's short journeys and cold start that does the damage.

120mph cruise only needs about 100hp in most cars. Well below the rated power of a car that would be happy to cruise there. Plenty of cooling airflow too.

Plus it's piston deposits rather than wear that are the issue if any here.
 
[TW]Fox;25307379 said:
Whilst this is obviously true is this wear material enough to make any difference to the expected life of the engine?

After all, is, say, a 545i sitting at 130mph really working any harder than a Fiesta 1.25 sitting at 80, which thousands of them do daily in the UK without grenading themselves?
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a piston ring is a piston ring. It could be the same on a 1.2 as a 3.0 so you can not look at it like that. The most important part is the strength of the engine not how much power it has or its percentage of top speed it is running at.
 
I would guess that stresses and strains on both engine, the materials it's made of, bearings, other moving parts of the car or bike go up exponentially with speed.

So a Fiesta at 80 is under much less strain as a whole than a 545i at 130... Likewise, if you sit at 200 in your Ferrari the stresses must be incredible.

I've been lucky enough to experience almost 200mph on a road before in my youth, and it felt like the very fabric of the vehicle was about to be ripped and shaken apart.... I now have a family and would never put myself in that kind of danger again. If something under load gave way at that speed, or even a tyre let out, it's goodnight. I wouldn't want to do 155 on a autobahn either, imagine a blow out at that speed

The whole thread is irrelevant though with my current family car having a average speed of just 28mph, my drive to work Type R has never been over 80mph since I've owed it, and I have no desire for it to ever do any more
 
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Depends on the car and what the engineers set out to achieve.
I'd guess a large German saloon is designed to be driven close to its top speed whereas a french ssuper mini isn't.
 
Flukester said:
I've been lucky enough to experience almost 200mph on a road before in my youth, and it felt like the very fabric of the vehicle was about to be ripped and shaken apart....
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I had a completely different experience. Stable, comfortable enough and handled that speed fine. Also, drivers in germany are a hundred times more aware then here in the UK. :p

 
Is that your mate of a mate's sisters brother-in-laws, window cleaners granddads R8? :p

I wouldn't mind smashing that down a autobahn. Bet you loved it. :cool:
 
I spent several hours trying to maintain this speed in my M3:

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In the end I managed to cover 330 miles in under 3 hours (Dortmund to Berlin). The car was more than happy to punt along at 155+ for as long as I wanted it to.

 
The funny thing is, people have spoken here about cars being designed for speed, yet, did anyone see the Spanish Top Gear trip where the Ferrari basically had been eaten away by the surface dust on the runway?

Unsure if it was exaggerated or not, but still!
 
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