The Future Of The Manual Transmission

shipo

"assume the slope of the hill is such that the vehicle will not slow-down if left in-gear, and the simplicity of the comparison becomes clear. in that case the vehicle in neutral will speed up but will continue to use nonzero fuel."

Well, using your very limited scenario, you've still missed one extremely important fact, at the bottom of the hill the car that was coasting in neutral will have more kinetic energy stored in the vehicle than the one that went down in gear. Assuming no stop sign (or other reason to use the brake) at the bottom, then the car that went down in neutral will cover the next given distance beyond the bottom using measurably less fuel, more than enough to offset what was used during the descent.

So, assuming that we take the measured roadway distance from top to bottom and then allow the car to continue traveling that same distance again beyond the bottom of the hill, the car that coasted will consume less fuel for the whole distance than the one that went down in gear.

Best Regards,
Shipo

boaz47

elias,
You solution is pretty much what many here have come up with. It addresses the future of the manual for the minority or even the niche. But my question has always been if or when manuals fall below five percent of so will the major manufacturers see a reason to continue to offer them to north american buyers? At what point does the effort become more than the return. No matter what some may think auto manufacturers are not "car" people they are business people. When record players fell below a point they simply stopped making them.

nippononly

You have hit the nail on the head as to why I do not have a hybrid - no manuals available. Although I must add that I am one for promoting simplicity of design - give it a small efficient engine, rip out 800 pounds of excess weight, and its fuel economy will be just fine thank you.

I do think that one day I may ante up for a BMW or Porsche, but it's not likely while the BMWs are overweight and overpowered (as they all are now) and Porsches cost $1000 for a tune-up.

jeffyscott: As a matter of fact, I attend very closely to the speed limit most of the time and do not exceed it in routine driving except occasionally to pass on the highway. But that is not out of principle or some great and reverent respect for the law, it is out of a quest for better fuel economy and less speeding tickets...where I have my fun is in the canyons...just how fast can I take those turns?....

:-P

boaz47

I can't say much about BMW because I have never had to work on one but I was on a pit crew for a friend in a Southern California Porsche racing club that raced out of Carlsbad. I wouldn't count on any long term relationship with a Porsche if you are used to Toyota. If you are a German car fan or could see yourself in a VW, Porsche may seem like a step up in dependability. But if you drive Toyotas or Hondas for dependability it isn't likely Porsche or BMW will hold up to the standards you are used to.

But if you are interested in driving a bit more spirited Porsche and BMW might be just the ticket.

ny540i6

Not trying to have the dimness of my bulb show too much, but when we make the statement "coasting, (or any other thing) uses zero fuel" am I correct in assuming that we are saying, "uses no more fuel than running the engine does?" If not, please help me understand....

habitat1

Before you scare nippononly away from a Porsche, consider that my first scheduled maintenance on my 911 was at 2 years or 20k miles, and every 2/20 thereafter. I couldn't wait that long out of paranoia, so I had an oil change and check up that cost me $230 at 1 year and 9,000 miles (9.5 quarts of Mobil 1 and a $50+ mega filter). That's it, so far. Except for new rear tires at 13,000 miles.

But, point taken that its still not a Honda or Toyota. My S2000 cost me a grand total of only $300 in maintenance over 2.5 years and 19,000 miles and that included Mobil One oil (5 quart) and filter changes every 4,000 miles.

stever

Here's some links:

steve_, "2007 Honda CR-V Rolling Resistance and Grade Logic" #14, 19 Sep 2007 8:56 am

boaz47

Maybe true, except Nippon is fond of dependable cars and frugal vehicles. Porsche hasn't scored well in any JD powers dependability study in some time. In the latest one Porsche is rated below Chrysler, Mini, Hummer and Dodge and even Hyundai. That would be a big leap of faith for Nippon to take. Being a California resident I also think 20K miles in two years is a bit light. I can also see our driving styles are very different. In three years I put 80K miles on my PT. I didn't have to use it but I was glad it had a 100k mile warrentee. But he can decide for himself and I was only making an observation based on the vehicles he has bought during the time we have been conversing.

boaz47

When you coast in neutral with most modern fuel injected vehicles the engine has to have enough fuel to idle fast enough to power the stearing, generator, brake booster, and so forth. When you leave it in gear the fuel can be all but shut off because the car itself will cause the engine to turn over and power those devices with nothing more than slight fuel input. So in effect you use less fuel because the computer doesn't have to keep the engine at 800 RPM without help. That is the readers digest version.

elias

shipo, in my scenario there is no bottom of the hill.
in the case of a real-world scenario with a real hill-bottom, if you want to use the hill's potential energy to increase your vehicle's kinetic way beyond the speed limit, instead of to use zero fuel on the way down, then good luck with johnny law. now *that's* real-world...

lilengineerboy

On the Subie, there is an instantaneous MPG meter which I believe is based on the fuel injector duty cycle. Living in a relatively flat area, I typically don't get to do a lot with hills, nor am I saying the meter is a calibrated scientific measuring instrument but:
1. Coasting on a flat from speed (like 50s) to 0 mph
a. Coasting in gear (5th) which would make the revs as low as possible, the MPG gauge reads 53 mpg
b. Coasting in neutral which drops the revs to the minimum level to keep the engine and accessories running, the MPG gauge reads 99 mpg.
c. Without engine braking, the car coasts for much longer in neutral (over 1/4 mile if need be)

2. Coasting on hills to maintain speed (like 50s)
a. Coasting in gear (5th) mpg gauge reads either 53 or 60-something
b. Coasting in neutral, the gauge reads 99 mpg
c. Coasting up the other side of the hill, the engine braking works against the car making it up the other side, coasting I can crest the top of the hill.

spiritinthesky

Excuse me, but just where are you getting this concept of "zero fuel" use by coasting "in gear"?

In all modern automatic transmisisons I am aware of, coasting in gear (i.e. taking your foot off the gas whether pointed downhill, level or uphill) does NOT shut down fuel to the engine, it merely reduces the amount of gas, since there is no load on the engine. I would expect the gas consumption to be similar to idle in neutral. As I am sure you are aware, when you actually shut down an engine or stall, even in gear, the power steering, power brakes, air conditioning and other accessories are lost. Hardly a situation that you would want happening every time you decide to coast.

And, as any of us with a manual transmission who have ever clutch started the engine, the cylinder movement when the transmission is placed in gear activates fuel injection and starts the engine. You certainly cannot have "zero fuel consumption" in a manual transmission when it is in gear or it would be constantly trying to restart itself.

I don't know where this concept of zero fuel consumption during coasting came from, but it certainly doesn't apply to any cars I've ever owned or am familiar with. The closest might be hybrids that shut down the gas engine when the battery takes over at low speeds and GM's "Displacement on Demand" which shuts down two or more cylinders, but other than that, I am quite certain that your whole predication of zero fuel use in a coasting situation is, simply, a farce.

Please take the time to cite sources for your claim.

elias

spirited one, my initial source was the owners manual for my 1989 IROC-Z (manual-transmission) - it was my first fuel-injected vehicle. that car had a high-compression LB9 305 engine, and when the fuel was entirely cut-off about a second after "lift-throttle", then the engine-braking from the zero-fuel-decel-mode was dramatic/obvious. exactly as described in the owners manual...
maybe ask a mechanical-engineer you respect about this?
it is indeed factual that any modern vehicle will continue running forever with zero fuel use, as long the rpms remain in excess of some minimal value, such as when going downhill or decelerating to a stop this is true for vehicles with manual-transmissions too, as long as you don't shift and as long as the rpms remain above about 1000 rpm.
as for where the concept came from, i think it derives from the work of Isaac Newton. It apparently was familiar to automotive engineers as early as the 1980s - or whenever the first fuel-injected vehicle was produced. the technology has definitely not been lost since then. google if you like, too, fwiw. cheers!

boaz47

a debate on coasting will have much influence on the future of manuals. It is not a question for me because I hardly ever coast. More out of fear than anything else. Once years ago I drove a Tractor trailer from LA to South San Francisco three days a week. Coming off of the back side of the Grapevine I would have to gear down to about third gear may forth and use the Jake brake. Even then you had to apply the brakes to stay slow enough for the down hill speed limit. I had driven the road so many times I felt I knew it by heart. One day I decided that I would pop the truck out of gear after the last turn and see if I could coast all the way to Button Willow. I made one mistake, I popped it out gear one turn too soon. While I managed to make the next turn by taking the whole road I was way over the speed limit by the time I hit the bottom pf the hill. My only thought was how in the world would i stop if someone pulled in front of me going as fast as I was. I then thought about what would happen if I had a blow out. At 80,000 pounds I could have made quite a mess. Obviously I made it and at 3 in the morning there was no one on the road for me to run over but i was lucky. I realize I no longer drive with that kind of weight but it still has an effect on me to this day.

spiritinthesky

Are you sure that somewhere between learning about Newton's laws and buying that 1989 IROC an apple or three didn't fall on your head?

For the record, fuel injection was common in diesel engines in the early 1900's. I believe Mercedes first introduced it in production gas engines with the 1955 SL300 Gullwing. Not only is that roughly 200+ years after Mr. Newton left the good earth, it's about 30-35 before GM engineers put it in your classic IROC. My 1979 BMW M1 had one of the earlier (but not first) advanced multiport electronic fuel injection systems.

As for thinking that the injectors turn off and zero fuel is consumed about a second after you "lift throttle", I think your memory of the owners manual is a little clouded. That simply doesn't happen. Perhaps another apple to the noodle?? Most manual (and automatic) transmissions exhibit a slight delay in engine braking when you lift off the throttle. They do that by gradually reducing the fuel flow, rather than immediately dropping it to idle levels - so as not to put your head through the windshield. But they clearly do not stop injecting fuel into the cylinders altogether. Reduced amounts of fuel continue to be injected, the plugs continue to fire and the engine continues to run. I certainly hope you aren't going to contend that you had to turn the ignition key every time you coasted in your IROC to restart it. I know of a few GM's that displayed such a characteristic, but it wasn't called "zero-fuel-decel-mode". Rather it was known by the more common name of "stalling".

You are welcome to google or yahoo away yourself if you need help. But I think you have managed to so confuse yourself as to the basic mechanics of an internal combustion engine that you should just take a break.

P.S. I have a dozen or two ME's that work in my company. If you want to have your ME call my ME, I am sure we can get this straightened out. And, just for kicks, I hope you don't mind me using the "zero-fuel-decel-mode" in our next meeting with one of our microjet clients. It sounds so much nicer than "crash".

stever

That's the thing - there are all kinds of hits on Google and Yahoo that say if you are coasting in gear there's no need for any fuel to be delivered to the engine in a fuel injected engine. The ECU turns off the injectors. The engine won't stall because the wheels keep the engine turning.

The links I keep finding aren't from the SAE; they're more like this one.

I'd love to see something more definitive one way or another.

ny540i6

OK, I'm lost again.... last I knew, an engine needs fuel to run, so the statement "if in gear, no need for fuel" does not make sense to me.

I just did a supermarket run, which included a hill... rolling down I shifted to 6th, to reduce/eliminate the effect of being in the wrong gear for the speed. At about 30 miles an hour, "coasting", the tach showed around 1500 rpm. I depressed the clutch, RPMs dropped to around 800.

Maybe I am missing something, since I thought that a "turning" engine meant a "firing" engine, and a firing engine meant combustion, and combustion required both air AND fuel, and combustion means.... anyway, you get the idea.

So if I run out of gas on a hill, bottom line is that the engine will starve, no matter that the wheels are turning. And trust me... I've done this one lolol.

boaz47

True, but you do not need to produce HP to run the engine downhill. It is also true that while in neutral you don't need the engine to produce forward motion, gravity will do that. But even if you stalled the engine going down hill in 6th gear it would produce whatever RPM the speed dictated. So you could turn 1500 RPM with no fuel or with just enough fuel to produce combustion. However in neural you need to produce enough HP to keep the engine running however little that might be.

That is the explanation I have read and I cannot verify that it is the truth based on personal knowledge. Without fuel the engine simply acts as a compressor. But it simply could exhaust air rather than discharged exhaust gases. But I will assure you my little brother once got my dads car to go at least 1/4 mile down the hill from our house by simply releasing the Emergency brake. He got at least 1500 RPM without a key. He also got a wooden spoon on his differential for the effort.

texases

Odd little thread here - no real meaning re: future of manual. But here's something to consider re: supposed shutoff of injectors. Could not happen, because it would shut down the catalytic converter. Rapid lightoff and continued operation of the cat is critical for effective pollution control. Shut off injectors, no combustion, no activity in the cat, air flow cools it off, big pollution spike on resumption of fuel injection. That just won't happen.

boaz47

I don't think I said the fuel was totally shut off. But it could be. But I agree this has little to do with manuals verses automatics. However here is an article that might shed some light on the subject.

http://www.boston.com/cars/news/articles/2007/09/02/drive_it_forever/?rss_id=Bos- - ton+Globe+--+Today's+paper+A+to+Z

texases

He could be right, but I wish we could hear it from someone who actually knows. I've seen a number of technical errors in the 'Click and Clack' type of newspaper columns. This 'shuts of the injectors' piece of information really needs to be substantiated by some hard technical information. Anyway, I can't see where it would save much gas, it takes very little gas to keep an engine running when it's not under load.

jeffyscott

http://carsguide.news.com.au/story/0,20384,21210480-5001701,00.html

Doughty says idling in neutral or lifting off the throttle in high gears where the revs fall below 1600rpm is not going to aid fuel consumption significantly.

"Fuel is still being fed to the engine to keep it running. But if you throttle off and use the gears to keep the engine revs between 1600rpm and 2100rpm, the ECU cuts fuel to the engine, allowing the engine to be turned over by the drive wheels rather than fuel ignition in the cylinder chambers," he adds.

The ECU re-opens the fuel feed when engine revolutions are moving out of the nominated range or the throttle is depressed.

texases

Great article. So there is a very narrow (1600-2100 rpm) window where the injectors are shut off on their particular (GM/Holden) cars. Hard to see where that could be effectively used in day-to-day traffic.

elias

spirted sky pilot, your ad hominem attacks are obnoxious. too bad there's no way to selectively avoid your posts due to your rudeness. oh well, edmunds forums remain great despite the absence of that one feature. i have no investment in whether you or your dream-team of mechanical engineers believe or disbelieve the truth here. indeed it is mostly an academic/nitpicky argument with little real-world-usefulness. engineers tend to love that sort of argument, so you might want to float it past your gaggle of MEs so they can enjoy slapping you.
an engine does not need fuel to run, ny540i6 - it can run as long as the hill lasts, via potential/kinetic energy provided by the planet's-gravity/friction/tires/drivetrain.
T-for-Texases makes a great point about the catalytic converter, but it would only be relevant if EPA/NHTSA/whoever actually does a zero-fuel-downhill test in order to test whether catalytic-converter remains up-to-temp. i heard once that some vehicles were going to have electric-preheaters for the catalytic-converter in order to satisfy EPA cold-start tests. if those made it to production, they might mitigate the effect you describe, with zero fuel cost because the alternator is able to run just fine with zero-fuel-use, similarly via potential/kinetic/friction/blahblahblah.
bo-arizona-47, i think i like your reply/experience the best. it reminds me of one of my favorite songs: Harry Chapin's _30,000 pounds of bananas_. i've found a live/mp3 of it. maybe google/play it, or read the lyrics to see their relevance to your experience. sincere thanks for the memories from this GM/Holden driver.

nippononly

of whether or not you can save gas by shifting to neutral and coasting, I think manuals are GOING TO MAKE IT! ;-)

ny540i6

"Ad hominem?" LOLOL. Is this the long haired intellectual chat?

I will differ with you on one thing.... engines don't run on air.

Engines run on air/fuel/spark. So, for instance, if I am at the top of a hill, get car rolling, and shut the engine off, depress clutch, car will roll, engine will not run. If I let clutch out, without turning key to "run", engine will not fire. It will turn over, since the weight of the car turning the driveshaft will turn the crank, will move the pistons, but it is not a running engine - until I add spark, which causes combustion.

I know this to be true, since I am writing this from the scrapyard... seems when I went out to verify my thoughts I forgot that little ignition/steering column interlock, and there was a curve at the end of the hill... but another day for that.

Maybe the term "zero fuel use" is a bit too extreme for simple minds like mine.... maybe "minimal?"

stever

engines don't run on air

Don't tell that to Guy Nègre (link and link)

He's only a few years past his originally announced release date too. Maybe because the prototype only came as an automatic CVT.

ny540i6

LOLOL

Geeeze Steve! Should I post "cars don't run on chocolate milk?"

Man, you dig some good ones up!

Thanks. Now I might just harness my two kids and dog up for their production of "compressed air!" LOLOL

redsoxgirl

After my brother called me last night to express sympathy for the Red Sox loss (actually, gloat, since he's an Indian's fan), I asked him about this "zero fuel" discussion.

He made no claim for what creative engineering GM has employed in the past or present, but assured me that as far as Porsche goes, if you are in gear, or not, with a manual or Tiptronic, "coasting" will not result in the fuel injectors shutting down. The engine continues to "run" with ingnition and fuel injection.

I'm not going to elaborate on the explanation, or why repeated complete shut down of fuel injection and ignition would have adverse performance consequences. It appears that certain advocates of this zero fuel theory are convinced of its accuracy. But my brother suggested calling your local Porsche dealer to find out if and when they are having an " open house" with the factory reps. Usually about 1-2 times a year and a great opportunity to ask the experts. Or you can trust good old Joe Goodwrench. I really could care less, as long as Boston wins tonight.

irismg

If I decide to buy a manual transmission car for my next car, would it be a collector's item in future? The value would go up instead of depreciate like usual, shouldn't it? :shades:

qbrozen

did i miss something? Where the heck did THAT comment come from? And where does it fit in here?

ny540i6

Fit in? We worry about that now?

I'm trying here....I guess the point is that if manuals become extinct, then your newly purchased, low mileage Xmobile would have a greater chance of being collectable.

irismg

Collector's item - the future of the manual transmission. Duh.

irismg

Exactly right.

boaz47

Don't know how that might play out. The old three or the tree didn't add value to a car even after they stopped making them. I once seem to remember driving an old MB with a 4 on the tree. But that sure wouldn't interest the sporting enthusiast.

qbrozen

I guess it struck me wrong. I thought it was a bash on manuals ... yet I couldn't see the point since obviously automatics don't appreciate in value either. Guess I misunderstood.

qbrozen

Duh

You make my 7-year-old nephew proud.

nippononly

I think that might be the wrong analogy, because those were still manuals. What about cars with hand-cranked engines? Did they gain value when the electric starter came in?

Alas, boaz old chum, I fear many collectors 50 years from now will take the view you seem to take now: the automatic transmission was just self-evidently an improvement of an existing technology (the stick shift), much as the electric starter was an improvement from the hand crank, and thus the "outdated" technology gains no value by being eliminated.

They will never know what they are missing of course, but what the heck. By then we won't be driving at all, merely telling the computer where we need to go, how fast we need to get there, and how many credits we are willing to spend on toll lanes and expressways to save time in transit....

boaz47

Sounds like you saw the Tom Cruise movie as well.

cdnpinhead

whether you prefer to ride or drive. Those with automatics appear to wish that they could ride all the way to work (or wherever) with no thought or effort, preferably with someone else doing the driving.

Those of us with manual transmissions prefer to do the driving ourselves.

texases

Sorry, but no. I enjoy just about all of my driving (save some rush hour minutes), nothing to do with getting wrist/foot exercise.

ps - drove clutched cars for 24 years.

ny540i6

Thought process changes with.... age maybe?

I dunno, but i look at the arguments talking about how stressful and tough it is shifting in rush hour traffic, and I don't get it...

texases

You may have a point on the age, but I do question the 'anyone who doesn't use a clutch is a car-clueless zombie' way of thinking. I enjoy acceleration - starting, stopping, and turning, none of which have anything much to do with transmission type.

iluvmysephia1

because I can accelerate with gusto in my '08 Mitsubishi Lancer GTS with automatic CVT just as fiercely as I could if my Lancer GTS came with a 5-speed tranmission. And I do!

Clinging in to a turn and handling like a champ is just as possible with my Lancer's CVT tranny as it is in a Lancer GTS with a 5-speed tranny, too.

boaz47

It is easy. Simply describe with words what you have to do in heavy bumper to bumper traffic that starts, stops for three minutes. Starts and stops for two minutes. And does that over and over for an hour. Having done that for several years in LA traffic I could. But I can still tell you how it is done in an automatic. The car in front moves 25 feet. You take your foot off of the break, allow the car to roll forward 25 feet and put your foot back on the brake. Have some coffee and listen to the sound system. In most cases you don't even have to put your coffee down. No one that can drive a manual believes it is hard, it is just more trouble than it is worth, in heavy traffic.

habitat1

Thought process changes with.... age maybe? ....
I dunno, but i look at the arguments talking about how stressful and tough it is shifting in rush hour traffic, and I don't get it...

Me neither, been doing it for 34 years and if I get that "old", my wife has instructions to shoot me.

Of course, I have a solution for the rush hour that works far better than an automatic. It's called "start your own company". Previously it was called, "move closer to where you work".

ny540i6

Boaz....

I live in NYC. If I commute in to Manhattan at the wrong time I travel at an average speed of 10-12 MPH, taking 1.5 or so hours to go 15 miles.

As for "more trouble than it's worth", well, that is obviously an individual decision, however I like the level of involvement that I have in my driving. (And of course, I like the way it sounds)

boaz47

And that is fine. However just write down what you have to do in such traffic and it is easy to see why more than 90 percent of our population drives Automatics. And if you live where it is relitively flat manuals are a bit easier to drive in that kind of Traffic. Try the same trick north bound heading for Bakersfield out of LA on the Grapevine and see how your clutch and legs like it. It is just that kind of traffic that has made the manual a niche transmission for many commuters. Do you realize how many drivers in the US today don't even know how to drive a manual? When my son got his drivers license the tester had to go back in and get another tester because she couldn't drive a stick and didn't feel she could grade him. I took my car to the car wash three weeks ago and the girl that was driving the cars off of the line had to go get one of the other men because she couldn't drive a stick.

Yes I know some will say it is a shame and we as a nation are lazy but that will not change the fact that manuals are not likely to make a comeback in the US. And I have a feeling if Hybrids do succeed the number of manuals will go down even more. Nippon better be pulling for small diesels and they better get here soon.

Even in this forum in the house holds of the loyal and faithful manual drivers there lurks a automatic in most cases.

elias

ny540i6, i hope that was a joke about the scrapyard! please be joking, you latin-knowing habeas corpus ipso facto QED dude.
as for long-haired, yeah that would be nice. bald is beautiful?
engines don't run on air, but they are fantastic air pumps..
i love my standard transmissions but i could never deal with one in LA traffic. one weekend i drove my 89 IRAQ-Z 5-spd from the SJ bay area to/around LA after weeks of bad ergonomic telecommuting and got brutally acute tendonitis - totally disabled one forearm for 3 months - then it took 10 months to fully recover. i had to drive automatic cars with overboosted power steering for the next couple years! now i'm a lot more careful about ergonomics of both typing and driving.
don't let it happen to you , manual-transmission typist freaks !

coolmazda5

After 3512 messages in this thread I'm pretty sure this is a repeat of some old post in here, but for what is worth.

Wife and I will buy Manual Transmission cars until they completely die.

We don't care about resale value, weird looks or even traffic jams. My 2 cars, including a Mazda5, have such an effortless/soft MT (gear and clutch) that ergonomics is not a big thing. MT is just a lot of fun to drive, above any other transmission equipped car.

We learned to drive in different Countries, still both learned to drive in MT. MT means complete vehicle control in my non-car-expert but 19+ yrs MT driving experience. Although difficult, we are happy to still find MT, which fortunately in the US is usually matched with a low trim car, meaning a great price .

As for what may substitute MT? DSG, not CVT nor AT. Yes, it is not cheap now, but as soon as it matches the economics of an affordable car make, see you MT

I think this video says it all:
http://youtube.com/watch?v=gmMNRQ1GJ3o