Every RPM brings you closer to needing to replace something; anything under the hood that moves faster in correlation to the engine speed. Yes, it is good to vary engine speed once in a while, but not on a regular basis. We are talking about regular basis driving.
The “engine is designed to go to a certain RPM” theory is wrong when we are not talking about the engine lasting as long as designed to… what I speak of is maximizing total car life. Anything that does not maximize total car life is wasteful and unnecessary, in this case taking your car past a certain RPM that will allow you to skip a gear. Unnecessary, wasteful, period.
Er… If you find yourself in too high a gear and need a burst of acceleration, just change down, it only takes a fraction of a second. (In fact, a fast downchange in a manual is probably quicker than kicking down an automatic…)
Yes and no. That fraction of a second is actually longer than you think. A car can travel a significant distance during that time. Actually, to press the clutch, do the down-left-down again 5th to 4th movement, and let the clutch back out is probably getting up towards one second. In theory, it shouldn’t matter, but in the real world it does. A yellow light should provide an ample enough window during which it’s possible to either continue through or stop, but this isn’t always the case in practice. You’re driving along, and the light turns yellow at such a time that you really should stop - but a group of young dickheads changes lanes right behind you with no intention of stopping. You gotta go through. That one second lost because you were in the wrong gear is absolutely crucial. 5th is a highway cruising gear only, IMHO.
Well, it’s true that every engine revolution brings with it some wear. It’s also true that constantly running at low rpms can result in carbon buildup, and an ensuing loss of power and efficiency. But I think you’re badly overestimating the impact of skipping 4th when accelerating to 5th.
Suppse flusyndrome has a 40 minute commute, during which his average engine speed is 2500 rpm, and during which he accelerates to 5th gear, bypassing 4th, eight times. Let us further suppose that 3rd gear is 1000 rpm higher than 4th, and that he remains in 3rd gear an extra 15 seconds every time he skips 4th. I think this is being quite generous - it shouldn’t take anywhere near 15 seconds, and that’s a lot of acceleration cycles for freeway driving.
Total engine revolutions on the trip - 100000
8 x 15s is 2 minutes at an extra 1k rpm - 2000 extra revolutions, or 2% more wear. So something that would ordinarily wear out after 5 years would wear out after 4 years and 11 months, on average, assuming that the only component in its wear is engine speed. This impact will almost certainly be completely overwhelmed by other factors such as maintenance habits and other aspects of driving style. Change the assumptions to a more reasonable 4 acceleration cycles and 7.5 seconds/shift and we’re at 0.5% difference, or a whole 9 days over 5 years.
Obviously, habitually driving around in 3rd rather than 4th at less than freeway speeds would make the increased engine speed a significant factor, but I just can’t see how skipping 4th when accelerating to 5th would be an issue of concern to anyone not completely anally retentive.
No offence, but I think after 15 years of driving exclusively manuals I know how long it takes me to change down a gear. For a start, you don’t do all those things separately, but in one smooth movement. The clutch is going down at the same time the stick is moving, and reaches its lowest point around the time the gearbox is in neutral, and is already on the way up again by the time you start to engage the gear, and you are already piling on the revs. Not very kind to the gearbox, but in an emergency that’s not the highest priority. It’s not only useful at yellow traffic lights, but in the middle of bends that tighten up unexpectedly. I find automatics to be much slower to get into a lower gear using the kickdown techique.
Anyway, I agree with you that 5th is only needed on the motorway. If you’re in 5th at 35mph then you’ve already made the mistake. But thankfully actual sitatuations where that tiny delay is anything more than a minor annoyance are incredibly rare…
I have further analyzed my driving habits today, I tried to just drive unconsciously like I usually do and analyze the data. Turns out I NEVER Look at the tachometer, it took me a couple starts to realize that, I shift unconsciously by “feeling” engine strain, remember this ain’t no Lexus or Cadillac, we talking turbo Bug here with 1.8 engine.
I seem to have taken a liking to 3200 RPM, almost every shift was at that RPM in the tachometer, so I did a test, drove like I usually do, shift at 3200 RPMs on 1st, 2nd, 3rd and then just put it in 5th like I always do, it was very smooth, no discernible strain and just kept going at that speed (guess my normal cruising speed) of 52 mph, at which time my car was at 22 RPMs in 5th. This was not a particular fast start, just average as all cars around me were behaving similarly.
I then tried the 4th gear approach, same rpms to 3rd, then hit 4th and after I achieved my “subconsious cruising speed” which was again around 52 mph I shifted to 5th. At that particular point I was going at 2900 RPMs in 4th and went to 2200 RPMs on 5th. Honestly I couldnt see any difference going from 33RPM in 3rd----->22 RPM in 5th to the other approach of 33RPM in 3rd ----> 29RPM in 4th -----> 22RPM in 5th, the end result was the same and it wasn’t any smoother or less strained or nothing. Seems to me like a waste of time and an EXTRA seconds of strain on the engine to put it on 4th.
I concluded I may just go around driving like I do, I understand that this could all be improved by shifting at lower RPM’s and using 4th, or by going slower than the illegal 52 mph in a 40 mph zone, but you must understand this was a “test” of what I usually do and will probably continue to do, and if tha’s the case, then probably there is no effect on engine/clutch wear or mileage.
As for light changes, I noticed that too, my left foot is ready on the clutch and as I approach, any sudden light change prompts my right arm to shit to 3rd and go, or second and downshift/brake to a stop.
And so concludes my highly scientific randomized experiment I should probably publish it and wait inpatiently for the Nobel Prize.
Your post is true, but if you take 1 month off the life of something in your car from one trip, then you ain’t doin’ too good…
Carbon buildup is the only thing wrong with the way I drive my manual Ranger. But, I race it enough to counteract that, hopefully.
I am not anal, but I like to stay away from high RPM’s, especially since my truck has such good low RPM torque… I can get around town so easily with not even breaking 2.5k, and I match very well too, so it’s just my way.
Reread the analysis. The one month over 5 years assumes continuous behaviour over the 5 years. It also assumes (almost certainly falsely) that there are no other variables in the rate of wear.
On the surface of things, after reading this thread so far, I’d say there is a little bit of truth in both sides.
For the Pro-skipping side, I’d propose the following situation:
-At a stop light/sign, and you need to get from 0-35 quickly (pick any reasonable reason, e.g. a “narrow” break in traffic, that you can turn into if you’re swift.), but do not need to accelerate past there. In my '98 VW Golf, w/ 158K miles, I can do this with 1 gear change, leaving me in 2nd. But to drive along, with no speed change, 4th often times is the gear I’m looking for. So I skip 3, and go directly to 4.
Now, if I’m accelerating from let’s say 0-80mph heading on to a highway, I’m going to use all the gears, and settle into 5th towards the end.
IANAmechanic, but this is my 2nd manual transmission, and both have served me pretty well clutch wise.
I drive a 6 speed, which I admit is a bit of an overkill. Both 5 and 6 are overdrives, and it is nice to use 5 on city roads and 6 on the highway, to keep the RPMs at about 2.5k (my car, an Acura RSX-S, redlines at 7.8k and only starts developing real power at 5.5k). The car obviously lugs a bit at 35 mph in 6th and doesn’t in 5th. When I am nearing a light or at times which may require power, I declutch into second or third, or if the light is green, 4th. For normal stopping, I keep it in gear until just before it starts to lug, just as Cecil recommends. http://www.straightdope.com/classics/a980227.html
I skip gears regularly, as my car’s gear ratios are quite closely spaced. 3rd puts me in the top end of my power curve at 60 mph (around 6.5k) and 4th puts me at around 5k. So 4th is nice if I am trying to go from 40 to 60 in a normal fashion without having to floor the car, 3rd is nice if I am going from 40 to 60 in a hurry. Either way, I can go directly to 6th once I get to my cruising speed without using 5th at all. For city driving, I can accelerate to 35 in 2nd (if I need to do it in a hurry and 3rd if I don’t) and go directly to 5 for gas economy. Since my engine is built to deal with high RPMs, I don’t think twice about it. Maybe I should.
I drive a '66 Shelby Mustang Fastback with a 340hp 289ci in it. Loads of torque obviously, and it revs very freely up to 6,600rpm.
Recently, I fitted a Tremec 5 speed close ratio gearbox - the old 4 speed top loader was pretty tired. I often skip gears accelerating… from 2nd to 4th, from 3rd to 5th. Sometimes, if I’m just plain enjoying the gnarly mongrel exhaust note I’ll jump straight from 2nd to 5th - ehh… it’s no big deal. Regular oil changes, and being a good owner in terms of maintenance is far more important than being paranoid about maximising engine life.
Which, I might add, is a really fatuous arguement by the way. My understanding is that less than 2.5% of all vehicles are owned by the same owner from the cradle to the grave. The huge majority of brand new cars are sold within 4 years of first going on the road. If you’re like me, and you own a classic, you’re pretty comfortable with the idea of getting a quality engine rebuild every 15 years or so.
In closing, with “stick shift” cars the key is to always drive in the “right gear” for the right circumstances. If you’re coming up to lights, go from 5th, hold the clutch in and let it out in 2nd while blipping the throttle if you think the lights are gonna change as you’re rolling up. Indeed, learn how to heel and toe - it’s a totally righteous way to drive.
If you’re accelerating, do what’s kindest to the engine - that is, get up to cruising speed with as few gear shifts as possible and then slot into your tallest gear for optimal fuel efficiency. Unless you intend to keep the vehicle for ever, or unless you’re really skint broke, revving an engine within 2,000 rpm of red line means zip. I reckon fewer clutch movements and gear changes is a better aspect to concentrate on personally.
Look, kid, just because you’ve never driven a car with torque, thats not my problem. We dont all drive hondas that dont make any power until 5,400rpm.
You do not have to rev high to make power.
My car made (stock) 340ft-lb tq at the rear wheels at TWO THOUSAND RPM. YES, TWO THOUSAND. Thats 2,000 if you didnt know. It has an automatic, but if it had a stick, it would have absolutely no problem pulling from 2000rpm in a higher gear.
Skipping 4th gear is NOT harmful. Everyone does it and I’d LOVE to see someone diagnose a problem with your car and say “oh well this is because you skipped 4th gear.”
It’s not going to happen simply because its not a big deal.
This arguement is akin to someone posting asking if putting your blinkers on 150ft before a turn instead if 100ft is going to wear out the wiring in your car.
It’s not, and it won’t. Ever.
If you try to start off in 4th gear from a stop, and you’re putting high loads on the engine with low rpms, yes, you can accelerate wear. But skipping one gear WILL NOT CAUSE A PROBLEM.
Confused girlie stick shift driver looking around the corner.
6 gears? What one earth do you use the 6th one for? Is it just for going really fast on a really big fuck-off motorway? Seems a bit superflous to me unless you are motorracing.
Speaking here as one who normally ignores 5th rather than 4th. But this is because I live in rural Ireland and practically all the roads are small-ish.
P.s. I just love stick shift chatter. I am a very new driver, but talking to mostly Americans I get to feel like an expert (and, apparently, hot) just because I can drive a stick.
To bring a new point to the debate, you can even skip the first two gears. at least I did that on my '88 Golf GT sometimes by mistake and started in the third.
Harm to the clutch? I have no idea and I don’t care.
Huh? I don’t know about harm, but why would you want to do it? Unless the other gears were not working. I’ve accidentally taken off in second a few times but I find the car just doesn’t accelerate well and it’s really hard and a bit scary to turn onto a busy road that way.
Pookah, it was an old car with a wornout gearbox therefore the first gear had to be forced somehow. I mistook the third for the first sometimes as it is right the first. I agree, acceleration was pretty poor but it worked anyway.
My car is a 5 speed manual and my changing points are at 20/30/40/55 kph at about 3200 rpm. As I change up it drops to about 2300 rpm and will pull smoothly from there in any gear.
Generally in city traffic I work my way through all the gears but say I pull away from a set of lights on the Great Western Highway with 2 kilometres to the next set of lights and I’m running downhill, at 3200 rpm in 3rd I’ll be doing better than 55 so I simply skip 4th. It would be perverse under the circumstances to use it.
Aside from what you are saying, it is obvious that inside your head right now, the origin of your thoughts and motivations in this post are… <can’t say>.
How do you know what cars I have, or have owned. How do you know I am a kid?
Why are you bragging about torque here? Besides, 340 lbs. of torque isn’t that much… although I must say at 2 grand it is nice. But, how is that relevant? Surely the OP does not have a light vehicle with that much torque like you do… don’t you see your example is the exception? :o
Fact: If you have a stocker gearbox, on 90% of cars, if you take 3rd up so far that 5th will not lug when you try to accelerate up to the speed limit, you revved too high. I bring this up not because I am not anal about RPM’s, but because it is advice on how to prolong the OP’s car, which is what they asked. Simple. I never said you have to rev high to make power, where did you pull that out of? ASSumptions, ASSumptions… (A little advice: most of the people on this board are smart, so don’t go around assuming that since someone didn’t say something you agree with, that they are stupid kids. Maybe, just maybe, there is a communication barrier you are dealing with instead of a stupid kid? Hmmmm…)
Like I said, never mind whether your post is correct or not, even if there is a correct statement to be made here, get a life. This is friggin’ cars we are talking about here, not the holocaust. Give your fellow members the benefit of the doubt before you start trying them in a post about gears.
Geez, why don’t you at least try living up to your name?
TWO THOUSAND= 2,000. Ok, I think I got it. :rolleyes:
I should probably publish it and wait inpatiently for the Nobel Prize.