RPM = number of Revolutions Per Minute. Most commonly an acronym for engine crankshaft speed.

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Minimum RPM at idle speed

Looking at wikipedia, For a passenger-car engine, idle speed is customarily between 600 rpm and 1,000 rpm. For buses and trucks it is approximately 540 rpm. In case of many single-cylinder ...
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4answers
622 views

Why does the power output peak and then drop as engine speed increases?

I have been looking at the power bands for my car (2000 Opel Agila 1.2) recently, as I want to work out when it is best to change gear and stuff, as I have no life! This is the approximate graph I ...
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1answer
185 views

RPM bouncing when in idle, especially when AC in switched on

I have a diesel common-rail 1.5l engined car. Lately I am facing an issue where the RPM needle is bouncing in the tachometer when the car is idling. The normal idling RPM is around 820. When idling, I ...
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1answer
126 views

Engine revs to 4000 RPM without pressing gas pedal

I tried to start my car today but something strange keeps on happening. It turns on just fine, but once the engine is operating it starts revving to 4000 RPM even though I am not pressing the gas ...
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1answer
38 views

cause of Rough / fluctuating RPMs in low RPMs

It's not dying (hasn't yet) but when the car is idling or in low RPMs the car (Mazda Protege 5 2002) is fluctuating in RPMs. Also, the last start was rough. I've had issues with air intake before ...
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1answer
45 views

Can frequent engine lugging lead to blown head gaskets?

I've heard that prolonged driving at low RPMs (AKA "lugging") can cause head gaskets to blow. Is that true and, if yes, can you provide a lowdown of the causality?
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1answer
231 views

Does using the entire rev range of a car damage it?

On my standard 2000 1.2 Opel Agila, I often have to get to about 5000RPM to join a fast road on a steep (1 in 10) hill, as it is gutless on hills. I have to do this almost every day, and I have ...
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2answers
378 views

Why does diesel engine have redline much lower than petrol engine redline?

why do diesel cars redline at around 4500 rpm whereas petrol ones around 6500 -8000 rpm? Does this have something to do with the compression ratio?
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0answers
160 views

1992 Mitsubishi 3000gt sl. no power and won't go above 2k rpm

I bought an automatic 1992 Mitsubishi 3000gt sl 2 days ago. I got it cheap knowing it would have problems, and that's why I'm here. When I put it in drive and slam on the gas the car just simply ...
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1answer
54 views

Installing an RPM meter

I need to install one in my car, as it doesn't have one, what modifications do I have to do? Edit: My car is: Suzuki swift 1996 But I would like the answer to be generic, as to what to look for if ...
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1answer
129 views

Why doesn't my rev limiter bounce?

I have a BMW 630i Steptronic from 2007. If I floor the pedal in neutral the RPM is of course limited, but it doesn't "bounce" like regular rev limiters. Instead it keeps a constant and "clean" RPM. ...
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5answers
6k views

What modifications need to be made to an engine to enable higher safe RPMs?

I first had this question while playing a racing game - it was a touring race with BMW 320i's, and I noticed that I could rev up to 8,500 RPM before shifting gears. Now my car (an older 320i), ...
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3answers
106 views

How do I reduce engine idling rpm without stalling it?

Considering idling losses are present in every engine, reducing the idling rpm might be providing significant savings. But, as I noticed on my bike, the chances of engine stalling increases with ...
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1answer
691 views

Suzuki GSR600 low idle revs and unstable

Just a week ago I noticed in my motorbike unstable rpm, +-300rpm. But today I found that the idle rpm are below 1000rpm, at some points around 500rpm (Normally is 1500rpm). I'm due for the annual ...
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0answers
13 views

Is RPM tied to gass usage? [duplicate]

This may be a stupid question, but one that has long intrigued me. Does running an engine at high RPM use more gas than running it a lower RPM? If you are in too high of gear, and the engine is ...
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0answers
79 views

2000 VW Beetle-Manual Transmission: Shakes at low rpms when acceleration is too high

I've been driving the car for about 5 years now, the car belong to my mother before that. I noticed the problem first in late September, early October. When I shift into a gear and accelerate, if ...
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4answers
3k views

Is starting idle RPM always lower in colder temperatures?

I've noticed that my 2008 Jetta 2.5L 5W40 generally starts up with an idle RPM of at most 1.2K RPM around the freezing temperature (say when the temp sensor reads 33°F), or even at just about 1K ...
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1answer
46 views

What Means Fuel Shut Off?

What does fuel shutoff means? I searched it up before, but the answer is not what I'm looking for. For example: The Ford Lighting's fuel shut off is at 5,400 RPM.
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1answer
177 views

2004 LEXUS GX470

I have a 2004 Lexus GX470. I am having this problem where as I accelerate, my RPM goes up to like 5/6 and my speed is not going up. If I back off the pedal and try again it sometimes will ...
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1answer
543 views

Clearing a P0507 on a Dodge Stratus

My 06 Dodge Stratus (4 cylender) is showing a P0507 off of the Torque app. My idle is sitting at near 1100 rpm versus the standard 800. I read up on the code and started looking for a vaccum leak ...
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1answer
63 views

2008 Ford Fusion throttle sticking?

I have a manual-transmission 2008 Ford Fusion SE. It's a great car but I have been having some problems with it recently. Firstly, the throttle does not seem to close when I let off the gas pedal. If ...
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1answer
5k views

Why does my engine rev up when I put it in park?

I've seen questions about engines revving when braking and when idling, but my engine revs way up (and stays up) whenever it's in park--whether on startup or shifting to park. It doesn't rev unusually ...
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1answer
3k views

Engine revs up when braking

Background: 2012 Honda Civic EX, 5-speed automatic, with no mods except a non-stock tire (ran over a large bolt). I keep it maintained per the manufacturer's manual and always see the Honda dealership ...
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1answer
129 views

Sudden increase in rpm when my car is in motion

I have chevorlet Enjoy purchased one year ago andgot it converted to CNG. Nowadays my car is giving problem of increase in rpm during running. It accelarates automatically but comes back to normal ...
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2answers
424 views

Toyota Corolla 2011 not accelerating when on 60mph or above

I recently bought a toyota corolla 2011 s from a local dealer with 80,000 miles on it. In my test drive everything seemed normal and was satisfied with the deal. But on a recent trip when i actually ...
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2answers
818 views

RPM jumps up & back down at 40mph

My question is for a 2006 Dodge Magnum, 2.7 liter engine. Just over the past month or so, I noticed when I'm cruisung, just coming from a dead stop, when I'm at 40 mph my car kinda feels like it ...
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1answer
292 views

High RPM and engine heating on 2001 Subaru Legacy

I have a 2001 Subaru Legacy L station wagon with 143k miles. I do not know when the timing belt was done, or when the spark plugs were replaces last. I only know that the brakes, tires, and one of the ...
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0answers
28 views

Does “slogging” an engine (open throttle at very low RPM) increase mechanical wear? [duplicate]

When I was taught to drive, I was told that "slogging" the engine - open throttle at low RPM, e.g. 1000 RPM - was bad for it. Particularly when driving up a hill as that means you'll be stuck at that ...
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0answers
1k views

Fuel Consumption and other Fuel related data from basic OBD-II parameters

I want to know how can i obtain the values of Fuel Consumption, Fuel Economy and other fuel related information from basic OBD-II parameters like Vehicle Speed, RPM, TPS etc. I have noticed that not ...
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2answers
1k views

What determines when an automatic transmission shifts?

I'm working on developing an automatic bicycle (mostly microcontroller based) and I'd presume I'd be shifting in a similar way to a car. So my question is, what factors does the transmission take into ...
4
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1answer
2k views

RPM fluctuation when maintaining speed in high gear

I recently got an oil change on my 2008 Audi A4 Quattro. Now I notice that when I am cruising in 3rd, 4th, or 5th gear (but not 6th), and I am at about 1200 RPM, the tachometer is not stable. The ...
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3answers
11k views

Engine power specification at different rpm?

Car companies advertise power of an engine at different rpms. Car 1: 80 PS at 6000 rpm Car 2: 85 PS at 6500 rpm What does the power at different rpm mean? Does it mean Car 1 has better power than ...
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1answer
1k views

Subaru Outback 1998 high idle rpms and CEL P0507

My wife's 1998 Subaru Outback threw a check engine light the other day, and when I read the code, P0507, it corresponded to a problem I'd noticed for a while: high idle rpms. The problem is most ...
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1answer
3k views

Typically in what RPM range should one manually downshift an automanual transmission?

Related to this question and TMN's answer: What's a good RPM range to safely downshift an automanual transmission manually? My car does it for me when the RPMs get really low, but that throws me off ...
5
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3answers
3k views

Does accelerating faster worsen fuel efficiency?

I've often heard that accelerating harder makes for bad fuel efficiency, but have yet to be given a sound explanation of why. Naturally this makes me question this advice. Now obviously when you ...
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1answer
201 views

1980 Suzuki GS 850 trouble at high rpms

I have a 1980 Suzuki GS 850 and I am having a problem where the rpms spike when I really get on the throttle. If I slowly accelerate there is no problem, everything runs smoothly. When I'm on the ...
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1answer
142 views

Tachometer doesnt show correct RPM sometimes

On my Honda CBF 150cc , the Tachometer shows RPM correctly when i'm at a constant speed. But some times when i slow down and accelerate the RPM Needle moves unexpectedly. (say to 0 even i'm at a ...
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2answers
1k views

Is alternator rating at pulley rpm or engine rpm?

I just got a new alternator for my jeep that says 160amps at 2k rpm. Is this rating for the pulley rpm on the alternator - or is it the rpm of the engine? Also, if the pulley is spinning slower than ...
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2answers
250 views

Do all engines typically support the installation of a crankshaft position sensor

I have recently purchased an 800cc dune buggy but unfortunately it doesn't come with a RPM sensor so I have been looking at my options in terms of installing one. In the process I have found that the ...
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3answers
4k views

Is it harmful to drive at high rpms

Does driving at high RPMs (3000-3500) in a manual transmission car cause any extra wear and tear to any mechanical parts? It obviously hurts gas mileage, but does it hurt anything else?