After reading the 'mechanical sympathy' thread, it got me wondering whether reving to the limiter is or isnt mechanical sympathy.
I regularly drive my cars to the red line and it doesnt seem to have done them any harm. My rover 214 is on 111,000 and my 75 on 216,000. Of course, they have never been thrashed from cold and only after a long run do their legs get stretched!
What do other backroomers take the tacho to and does it do any long term damage?
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Red line frequently for all of it's life. On 76,000 miles.
Cars are meant to be driven. The red limiter cuts in to stop damage surely?
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I chug along at about 2000rpm most of the time but once a week I rev it through from 2nd to 5th until the limiter cuts in.
Megane dCi
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Red line frequently for all of it's life. On 76,000 miles.
the mystery of Adam's 15mpg Focus start to become a little clearer :)
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>> Red line frequently for all of it's life. On 76,000 miles. the mystery of Adam's 15mpg Focus start to become a little clearer :)
...and that's just the oil consumption!
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What - you mean consumption increases with the revs??? ;-)
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He never leaves 1st gear though.
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And now back to the question please.
DD.
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i never take any car to the red line as its at the border of tinkerbell and she dont come cheap.(no engine rebuilds do)
If the engine was a sporty number and i knew its history then i might just occasionally take it to 500 revs of the red depending on the make,but would be wary.
Blueprinting and balancing would be the order of the day if you take a "cooking" car here often.
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\"a little man in a big world/\"
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>>i never take any car to the red line as its at the border of tinkerbell and she dont come cheap.(no engine rebuilds do)
If the engine was a sporty number and i knew its history then i might just occasionally take it to 500 revs of the red depending on the make,but would be wary.
Blueprinting and balancing would be the order of the day if you take a "cooking" car here often
Bearing in mind depending on treatment of vehicle,not all engines will allow you to red line,they just wont go there
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Steve
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If the engine was a sporty number and i knew its history then i might just occasionally take it to 500 revs of the red depending on the make,but would be wary. Blueprinting and balancing would be the order of the day if you take a "cooking" car here often.
om, you said it. I wanted to say that with a well worn engine, if you don't know how it's been driven and it's a car that will trundle around happily at low revs - as nearly all are - it is very unwise to take it anywhere close to the red line. Broken piston rings are quite likely to result - I've done it twice - and although with some cars you can replace them without removing the engine, it's not the sort of job you'd want to do.
A sad thing a broken ring. So small but so crucial. The other thing that destroys them is gross overheating.
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The engines love it, unless they're in poor state of repair, or they have a highish mileage which was attained by an old lady pootling about. If a car has done a high mileage at low rpm, it will have worn in sympathy with this and revving it high may make thinhs like piston rings hit tight spots or carbon rings.
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good point ishok the other thing is obviously valve bounce.
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\"a little man in a big world/\"
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The engines love it, unless they're in poor state of repair, or they have a highish mileage which was attained by an old lady pootling about. If a car has done a high mileage at low rpm, it will have worn in sympathy with this and revving it high may make thinhs like piston rings hit tight spots or carbon rings.
True I think - a friend once had a v.g.c. Mini from a relative that had been mollycoddled for years (the car not the relative)- after a few weeks of enthusiastic use it was suffering from very high oil consumption and as it turned out broken rings, presumably as a result of the pistons going where they had never been before.
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>>the mystery of Adam's 15mpg Focus start to become a little clearer :)
Yes,but should not harm the engine as long as red line is not held for too long.
often do this myself to clear cobwebbs from engine,especialy when driving through town for days at a time,carbon build up should not really happen on modern engines-for me its habit and you get to know engine response when lead foot is sometimes used,ie you can feel response is not up to par so a quick thrashing seems to solve it
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Steve
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Serious answer - I think there is benefit in using the full range from time to time otherwise the moving bits don't have the chance to bed in properly.
OTOH I have noticed over the years a strong correlation of constant hard use, especially from cold, with high engine wear and other mechanical failures - one of the local lads took over his Mum's tidy Fiesta and six months of full revs through the gears, wheelpsin starts etc reduced it almost to scrap. Moderation in all things!
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Regularly use the full limit of the revs, but never hold it there. As an owner/driver of 2 VVT cars they need the revving anyway - My better half doesn't thrash her mota, so when I use it, it get's the revs once warmed up ! I'll rev mine to near the limit at least for just once a day !
Both run on synthetic oil changed regularly at each 6 months (get it cheap and both cars only take 2.5 - 3 litres) plus OEM filters.
Oil change rather frequent, but why not, esp. if you get it for a good price and don't pay dealer 'costs' ?
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My Focus doesnt have a marked redline. I have, briefly seen 7000 just before the rev limiter, but usually try to stay below 6000. Even that isn't used every day.
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3000 rpm most ecinomical but most cars put out peek power well under the red line and beyond that power decreases.
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correct school boy but you try telling your pupils that as they thing revs=power
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\"a little man in a big world/\"
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Yes, people my age seem to think that although they have a 1.2 corsa that they can outdrive and outperform most vehicles on the road. I also find it funny when I see them pull away from the lights everytime they wear 3000 miles off the tires.
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Modern multivalve petrol engines are designed to be revved, and as long as they are properly warm, it does no harm.
I regularly take my Impreza Turbo to the red line, and it is running better than ever at 102k miles.
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Modern multivalve petrol engines are designed to be revved, and as long as they are properly warm, it does no harm.
The higher the engine speed the greater are the forces on all moving components, and wear caused by friction is greater.
I learned my lesson in my Chamois which ended up needing new valves after 25000 miles because the original valves had stretched to the point where it was no longer possible to achieve the specified valve clearances.
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L\'escargot.
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gear changes at or below 3,000 revs and sits at about 3,500 on the motorway, dad has occasionally taken it up far to about 5,000 i think.
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Temporarily not a student, where did the time go???
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All time high of 5500rpm......on two occasions. Red hatched zone is drawn at 6000-6300rpm, but even at 5500 I was past the power peak anyway (although it still seemed to want more!).
In day to day usage, 3500 is rarely exceeded with gear changes being made at or below 3000, although to do 70 will need about 3900 in top. I can't really see the point in making it a weekly task to rev an engine to its maximum speed. As far as I?m concerned, the chances are I?ll do it without particularly meaning to during day to day driving, once every few months.
Personally, I don?t think revving an engine to its limit would do any harm, as long as its warm and well maintained. Revving beyond the limit, well your asking for trouble but I suspect this is impossible to do these days with limiters being fitted to everything. When you see what Autocar/Motor used to put the test cars through, I often wonder how many expired during road tests. 7000rpm out of the long-stroke Maxi engine, surprised it didn?t try to spit a piston out!
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Full running temperature, non-degraded oil and EXPERIENCE OF HIGH REVS FROM NEW. Otherwise discretion the better part of valour, as more often than not in real life.
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More revs = More wear
But always keeping the revs low, can risk carbon build up, and in extremis, if the engine has never been to to the limit, things may well not work right when finally asked to.
All engines should be high rev run in, ie do the revs, but keeping the load low, as part of overall running in. A second hand car of my fathers actually improved its oil consumption when properly shown high revs - we suspect it was never fully run in.
All of my engines have been to the limit, and the sports car goes there more often. But I'm prepared to replace the engine more often.
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As for my 320d I have taken note of HJ's advice (FAQ) about running in and running a diesel car, so I give mine a fairly regular 'burn' at around 4000 rpm (but not into the red).
www.honestjohn.co.uk/faq/faq.htm?id=32
In any case the MoT test specifies an environmental test at near-limit revs (on a pre-warm engine).
Oz (as was)
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More revs = More wear
So how come variable valve engines (Honda and Toyota - to name a couple) don't wear out quickly then? Some of these engines can be taken up to in excess of 8,000 rpm. They don't seem to wear out any quicker.
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>> More revs = More wear So how come variable valve engines (Honda and Toyota - to name a couple) don't wear out quickly then? Some of these engines can be taken up to in excess of 8,000 rpm. They don't seem to wear out any quicker.
I think they might if you drove around at 8,000 revs!
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>> More revs = More wear So how come variable valve engines (Honda and Toyota - to name a couple) don't wear out quickly then? Some of these engines can be taken up to in excess of 8,000 rpm. They don't seem to wear out any quicker.
Because they're made by Honda and Toyota!
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MoneyMart
Current car: 55-reg Audi A4 2.5 V6TDi Quattro flappy-paddle
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More revs = More wear
This is true, but in most cases I think this will be negligible. In any relatively short journey the most wear will probably happen when the car is warming up, even if you thrash it after it has warmed up.
15 minutes of warming up will probably do more damage than 15 minutes of driving at operating temp, reving upto the redline occasionally. When you do reach these revs you would normally change up anyway, so you would spend no more than a few seconds at a time at these revs.
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My 5 cylinder 2.4 litre turbo diesel (85,000 miles) is revved hard in first and second once a day. The red line is at 4000 rpm and with a limiter set at about 4300 rpm.
Unless I do this the engine starts to be come sluggish due to the muck not being fully blown out of the exhaust. I do leave a small cloud of smoke, but then nothing for the rest of the day.
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Roger
I read frequently, but only post when I have something useful to say.
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ocasionly, although most of the time only upto 5000 revs. I tend to give the vehicles a good flat out sustained hi speed motorway run once a week (95mph plus)as oposed to changeing gear at high revs.
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From the examples of cars being reved hard and being fine it just shows how good reliability on a wjole is now, apart from the odd one. Probably if you constantly reved high with short distances cold then you would probaly notice the difference after a while.
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The dust has been pushed back to about 3500 rpm on my elderly Citroën......
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More revs = More wear
Not necessarily true.
I think back to a motorcycle magazine that stripped down the engine of a CBR 600 that had done 100,000 miles IIRC,and the engine was subject to an in depth investigation as to its health.
Said engine,had been the subject of a lot of different styles of riding,including being regularly bounced off the rev limiter,raced around the TT circuit in the Isle of Man and much more.
The engine expert said afterwards that it was well within factory tolerances,and was in fine condition.
Then again,it was a Honda.
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Was that the one that also hadn't been serviced for 25,000 miles or something daft?
If I remember rightly, the only problems were a lumpy idle and slightly worn rocker gear...
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>>Because they're made by Honda and Toyota!<<
Or Alfa
My 1.6TS has done 125k, has never missed a beat, has all original components (except for service items), and still reaches top speed very sweetly, and the rev limiter still cuts in at ~7500rpm.
Not all Alfas are as many peaple like to believe!
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