What is a good RPM to keep your car at (to not go above) if you are worried about wear/tear on a car?
also my car doesn’t have an RPM guage on the dash. however it has about a 140 hp 2.5 L engine and since i never floor it i doubt i go over 4000 even when going uphill.
There is no single answer here. Modern motorcycle engines cruise at 6000 rpm or above with no negative impact on life while truck diesels often should not be operated above 2500 rpm.
Engine wear depends on more on piston distance traveled than any other factor. This is directly related to gearing and not rpm. There are added side loads during acceleration so hard acceleration can shorten life, but again, that is not directly rpm related. High engine speed does add loading to rod bearings and, to a lesser extent, main bearings, but most modern engines are so overdesigned in this area that I would not expect a problem.
Given that you’ve got a relatively small, low horsepower engine, I don’t think you can turn it fast enough to hurt it unless you just leave it in low and drive wide open. On the highway, you can’t go fast enough (even ignoring the speed limit) to over-rev the engine. You just don’t have enough horsepower.
By and large, I personally reckon a good rule of thumb is to drive at as low an rpm as your car will comfortably accept without going so slow as to impede other drivers while you’re accelerating.
Now, I know, I know… that sounds really boring and ultra “old fuddy duddyish” and I don’t disagree - but in the context of super duper longevity of your car - certainly, the research shows that the more “softly” you drive it, the more it’ll thank you for it. And this includes braking too - the softer you apply your brakes, the longer your pads and discs will last and basically, all around your car will go through less stress and wear and tear.
But that being said, some vehicles are simply designed to have the living bejesus fanged out of 'em occasionally. I mean, it would be sinful to have a highly strung Lamborghini or Ferrari and to drive it the way I just described. So many of the parts would suffer through “lack of use” if you know what I mean - and more importantly, high performance engines (including high performance motorcycle engines) really do like having the cobwebs blown out of them on occasion. To this end, a good 150 mile fang at high speed once every month or two is just the tonic.
Overall though, in city driving and suburban driving, the softer you drive you car the better it is for prolonging the quality of the car. And you’ll get better fuel consumption too.
In answer to your original question, I would imagine a typical 2.5 litre engine would easily and comfortably handle 4,000 rpm on a regular basis - however I would also contend that it would easily get you around town with a 2,500 rpm crossover point between gears too.
I once used to own a wonderful Alpina E21 BMW 323i with a very highly strung 2.7litre Alpina straight six in it - a real screamer engine in a very, very light small coupe - and it was a car which never once didn’t rev cleanly and smoothly all the way to 6,500 rpm almost every time I drove it - even without changing spark plugs for 2 years at a time.
I’ve always driven the piss out of my German cars, and never had a single engine problem. (Except for a snapped timing belt, but that was because I severely underestimated its age.)
My driving habits cause me to regularly tag the redline. Even when I drive “average” I don’t shift until 4500 or 5000 rpm. The aftermarket chips in my cars take raise the factory rev limit from, say, 6200 to slightly more than 7000 rpm. I rearely hit this new limit, but I often plunge the tach deep into the old red zone.
Will my driving this way shorten my engine’s life? Probably a little. But they’re always well-maintained motors, and I doubt i’ll notice the shortened life expectancy. The last car I retired was an Audi with 245,000 miles. I put the last half of those on myself. It got totalled, but still purred beautifully to the very last mile. I don’t know how long it would have lasted with my aggressive driving habits. But if 245k (minimum) is a shortened life expectancy, I don’t think the full potential mileage really matters much.
I’ve driven this way for years, and have put hundreds of thousands of miles on my cars this way. I’ve never had any ill effects from it. But then again, these are all German cars, and I can’t speak for cars of inferior origin. 
I also hear talk from time to time of cars that are never revved high having more problem with carbon buildup on valves and such. It follows that getting up near the redline on occasion does a good job at “blowing out the cobwebs,” as the above poster mentioned. I don’t know that this idea is restricted to exotic high performance engines, though.
I say the redline is there for a reason, and everything under it ought to be safe. If it weren’t, they’d have made it red, too.
If you are worried about lasting only 300k as opposed to 500k miles, then alter your driving. (Just don’t wind out the engine, if it’s a stick, of course.)
Proper maintenance is king, otherwise. If you are a high RPM’er, then more frequent oil changes are in line.
Good grief guys, can we use some technical terms here? It’s not “an RPM” it’s the engine speed, which is measured with a tachometer. Hate to be a stickler but that was driving me crazy.
As far as answering the question: as has been said before, there is no correct answer. In fact, engines rely on speed variation thoughout their life to wear evenly and properly. Your best bet is proper maintenance and not driving all over town like Michael Schumaker
Without repeating the “there is no correct answer” part, there is also the fact that most car failures isn’t even engine related. As long as you do normal maintance and don’t obviously abuse your engine (over reving past red line, no engine oil etc) you’re more likely to kill your tranny than your engine (transmissions, especially autos, get much more abuse from drivers than any other part).
You shouldn’t worry so much about your engine. My mini-van went through 3 transmissions before the engine developed lifter tap (chrysler trannys suck) and had maybe 4 alternators, 10 water pumps and 2 suspension replacements and a new rad in it’s 400K KM life (over the course of 10 years)
My Bonneville with 260K KMs on it only went through a new rad (had it for 3 years).
My new 1.8L 180 HP toyota engine in my Matrix gets a work out everyday with at least 3-6 red line accellerations on the highway and continuous high-speed travel and haven’t had an issue yet in it’s first 68K KMs.
It is a joke when the speed shop says this is for race only - I drive my Fords and GM’s like they are on the track all the time except for rush hour - other than rush hour the streets are empty around here - well many of them.
Buzzz the hell out of them and SLACK on oil changes if you go by the every 3,000 mile theory. 200K+ miles on lots of cars and trucks and no engine trouble.
Where you see ware is on the water pump, alternator, and such. But it seems that even people that are easy on their cars need a water pump or such about every 100K.
The less throttle used is less stress on engine, but don’t stress your head worring about it - it will be fine. BTW, you are not trying to haul thousands of pounds in the car are you?
While you are correct that wear depnds more on piston distance traveled, this has nothing to do with the gearing, and everything to do with engine speed. The piston always travels the same distance (a revolution). The only thing that changes is the frequency with which it makes the trip (revolutions per minute – RPM).
Sure a piston will travel a greater distance in 1st gear at 30 mph for a mile than in 3rd gear at 30 mph for a mile, but this is because the engine speed is lower in the gear.
Not sure what you were objecting to. Gearing directly affects engine speed, given that most people really drive by the speedometer, not the tachometer. (Those that don’t lose their licenses quickly.) Way back when in engineering school, we evaluated piston travel per mile. The important factors were gearing and stroke. Long stroke engines pay for their torque and displacement advantages with increased wear unless the rpm is limited by applying appropriate gearing changes.
I was just objecting to your statement regarding piston travel distance (“This is directly related to gearing and not rpm.”).
It is directly related to rpm.
KenGr is talking about engine wear per unit distance. Number of piston motions per 1 mile travelled is dependent on gearing and nothing else. No Disguise is talking about engine wear per unit time. Number of pistion motions per 1 hour of driving depends on engine RPM and nothing else.
But a taller tire effects the final drive!!! - lol
and of course a longer connecting rod reduces some of the ill effects of a longer stroke.
what was the op?
distance, time…
Ever hear of a torque converter? It’s not a fixed 1:1 ratio.
Anyway I heard it is good for the ol’ IC engine to occationaly do a WOT run as it helps the wear pattern and also helps move things along such as carbon deposts.
Automatics?! gasp I won’t even get into all the nasty things I scretly (or not-so-secretly) think about just about everyone that drives a slushbox.
But I will say I think the point is moot, because since when to people who drive automatics know or care enough about cars to worry whether high rpm’s will damage their engine?
Dis I really say that? Oops…guess I let some of it slip out anyway. :o
Ok, I have listened to all the flap.
You go east and I’ll go west and I’ll meet you half way. Near OH/WV/MD.
I trust my automatic trans Buick has enough to deal with your, sight unseen, Audi.
BRING IT ON!
Remember, I said “just about everyone.” There can be exceptions.
Now if you’re putting yourself in the same category as the typical 30-something Toyota-Camry-driving woman, then I understand your defensiveness. But if not, you’ve got nothing to worry about.
Besides, I wouldn’t line my current Audi up against much of anything. I’ve got a project VW that’s a whole lot faster. Maybe not faster than a typical old-school tuned F/I American V8…but it holds its own.
I bet you’re thinking drag race. Anyone can run fast down the line, but can you make it past turn 1? I say an autocross is a much more telling test…and if you’re up for that, then bring it on!
This hijack is officially over… [/dick waving]
Auto cross - no problem. Not really set up for that but it is very doable. I definitely enjoy the type of track that allows one to go through the gears at WOT. Autocross is fun but really do not get to feel the power long enough. Also, for all the tire smoke of drag racing, just one day of Autocross will put the serious hurt on some tires.
I love driving and watching the VW’s on the off-road type tracks. Those cars will take what ever you put it through.