Is occasional red-ling of the tachometer (or high revving) good for engine or keeping the revs 3000rpm max better?
Is occasional 5-6000rpm good for engine or driving 3000rpm max better?
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For an engine in decent condition, running it through the power band is good! If you take German cars for instance, they were intended to sit near redline for long periods of times with no issues...that's why I feel safe going up to 7,000 rpms in my BMW 325is with 132k miles on a daily basis
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I redline my engines all the time.
If you buy a used car that was never driven at high RPM, guess what happens if you decide to flog it?
If you buy a used car that was never driven at high RPM, guess what happens if you decide to flog it?
So how much flogging would it take to grenade an engine that's been driven gently throughout it's life?
what benefits if revving high?
Ever hear of the 'italian tune up'?
Long as it is done with a load on a fullly warmed up engine it is nice to do.. Especially if you have variable valves. RPM's don't hurt it is sudden loading and unloading of the engine. Drive smooth.
All my cars get pegged occasionally, I consider it a good practice when done responsibly in regards to traffic safety and being smooth on the vehicle.. I can actually run a mode in the BMW that shifts the auto at redline each shift with no further input from me other than downshifting when I want to. Makes for fun, does some high velocity housecleaning inside the engine and it allows the ECU to keep the engine in optimal tune by letting it see some out of the ordinary readings.
All my cars get pegged occasionally, I consider it a good practice when done responsibly in regards to traffic safety and being smooth on the vehicle.. I can actually run a mode in the BMW that shifts the auto at redline each shift with no further input from me other than downshifting when I want to. Makes for fun, does some high velocity housecleaning inside the engine and it allows the ECU to keep the engine in optimal tune by letting it see some out of the ordinary readings.
my 88 528e redlines just over 5k rpm. At 3k, it is doing 88mph. Every so often, I will get near 5k in 2nd or 3rd. 308kmiles but I 'm not skeered
It's good for the engine. It's even better for traffic if you do it while merging onto a highway.
I also rev the 4.6L in my '05 Mustang when traffic allows. As others have said, it won't hurt as long as the engine is warm. I've heard a "myth" that might have some basis in truth. The myth goes like this: A certain car has been driven for many years by a granny, who has never revved the engine beyond a given RPM, say, 3000. A wear ridge has developed in the top of the cylinders, as is normal. Granny sells the car to some young guy. Being a spirited young buck, he drives the car hard, revving the engine to it's limit. The myth says that he ends up breaking a piston ring. The increased stroke caused by the stretching of the connecting rods by this suddenly increased RPM's causes the pistons to travel a few thousands of an inch further up into the cylinders, and the rings hit this wear ridge, thus causing them to break. Theoretically, I suppose it's possible. However, I doubt it's something that actually happened.
Even so, why risk it? Rev your engine regularly, and you'll avoid this issue!
Even so, why risk it? Rev your engine regularly, and you'll avoid this issue!
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Happens all the time when a kid gets a nice-looking used car and takes her out for a spin on the Autobahn, or if he drives with high RPM. I've seen it happen a few times to friends of mine -- when we were young and dumb.
The whole usable rpm range of an engine should be used. Setting the cruise control to 75 and going 500 miles without ever varying rpm is not a good thing. I'm much more worried about lugging an engine than I'm worried about one grenading at high rpm. Most engines cut off fuel anyway before you get a chance to over-rev it, although through stupididty and operator error it can easily be done.
When can you ever set the cruise control to 75 and drive for 500 miles?
The rolling roadblocks in the left lane just about guarantee you'll have to pass 'em on the right.
The rolling roadblocks in the left lane just about guarantee you'll have to pass 'em on the right.
I-80 in Nebraska and Wyoming.
Doesn't work on I80 in Indiana (even at 70MPH, the speed limit there, because there are many drivers on that road who only go 65MPH).
I am no engine expert but from what I have always been told the engine bearings are ecentric, not concentric.. meeaning they are slightly out of round to accomopdate a thick fluid wedge on the loaded side of the bearing. By runnning the RPMs up with no torque there may be parts of the bearing that are not constantly under hydrodynamic lubrication if the intended load is not applied. Your engine only produced enough torque to move the load, no more despite its ratings. So as long as you are moving the car it is producing some torque wheich should be good enough.
I lament that after I top out second I am beyond legal too.
[ November 30, 2005, 01:26 PM: Message edited by: Bryanccfshr ]
I lament that after I top out second I am beyond legal too.
[ November 30, 2005, 01:26 PM: Message edited by: Bryanccfshr ]
That's why you should flog it on the test drive before you buy it!
This ridge theory holds water not for old used cars but new ones during their break-in.
I've always heard one shouldn't drive at a steady speed/load/RPM for the first 500 miles but this is the first "good sounding" reason I've heard.
It seems most modern cars dump fuel for a ~10:1 (rich) AFR at higher revs in an effort to protect/excite the catalytic convertor. (Even more than needed for power enrichment) I wonder how with all that extra fuel one is blowing carbon out of the engine.
I've always heard one shouldn't drive at a steady speed/load/RPM for the first 500 miles but this is the first "good sounding" reason I've heard.
It seems most modern cars dump fuel for a ~10:1 (rich) AFR at higher revs in an effort to protect/excite the catalytic convertor. (Even more than needed for power enrichment) I wonder how with all that extra fuel one is blowing carbon out of the engine.
A good blast at full throttle and high RPM will help clean the injectors, valves, and C.C..
If evelated RPM were bad for your engine, carmakers would lower the redline accordingly.
Good explanation, thanks.
I always thought the logic behind varying the sped during the first 500 miles or so was to generate vacuum (during the deceleration phase) to pull some oil up onto the cylinder walls. This helps lube the rings so that they can seat better.
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