"The CVT: Learn it and Love it"

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I drove a 2014 Forester with the CVT and it wasn't bad. It's definitely different. The quote below is from the Forester forum. The CVT vs MT issue is very popular now that Subaru has a good CVT. It's also available in the 2015 WRX. This guy leaves out the fact that some drivers want to be more engaged when driving. Having a computer do all the work is no fun, although that's the way we are continually heading and there is no stopping it.
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The CVT and acceleration expectations. Before the CVT there was the manual transmission and the automatic transmission. While the automatic transmission masked a lot of driver inexperience through their electronic/hydraulic controls, the manuals required the driver to provide the control between the engine and the wheels. Anyone with experience knows when a MT is driven poorly... stalling, jerking, and the rest. But there are more serious consequences for driving a MT incorrectly, and some require engine rebuilds. Some are for spun bearings, some are for pistons with broken ringlands, and some are both. All because the driver didn't know how to manage the vehicle's torque with gearing vs RPM. But regardless of whether these mechanical failures occur, there is a certainty that at the least poor gas mileage occurres. Add in clutches, gears, and synchronizers to the mix and it's clear the Manual Transmission requires an intelligent and skilled operator... or else. Automatic transmissions, on the other hand, are easy. Modern automatics "think" for us. They have a Transmission Control Unit, or TCU, similar to the ECU, that does the thinking for the driver... even if they are inexperienced. Once CAN Bus OBDII became standard (CAN bus - Wikipedia, the free encyclopedia) vechicles became even smarter, and the engine and transmissions along with other systems, all cooperate behind the scenes. Paddle shifters, rev-matching downshifts and upshifts, and simply smashing the go pedal all get interpreted by the control systems that then provide what the driver wants without fanfare. Pretty nice. How does a driver of a manual transmission break a ringland or spin a bearing... and that those events are less likely in an automatic-equipped car? One scenario is when the MT driver is driving along in high gear and decides to go WOT, for whatever reason. Another is going at a slower speed in third or fourth gear at lower RPMs... and puts the pedal to the metal. In both cases the gearing is too high to permit the engine to move the vehicle very fast. This is where the trouble begins... going WOT tells the ECU to go to a set of circumstances governed by tables, called Open Loop. In OL there is a fixed value per RPM and Requested Torque for fuel, timing, AVCS, Boost etc. If the car cannot accelerate fast enough due to too high a gear, the airflow cannot sustain those requests and the engine works poorly at best. At worst it causes huge loads on the bearings and operating conditions that cause detonation. Not good. Where the AT would downshift or decouple the TC, the MT in the wrong gear labors. There is simply not enough room in a single post to present the total picture that supports these facts. Reader research, however, will provide corellation. Simply put, the issue is Ramp Rate. Require a vehicle to accelerate faster than it can physically respond to... and it will work poorly, mostly because of tuning parameters and airflow. Open the throttle to maximum without the gearing that allows the vehicle to fulfill that torque request (move forward) and it balks... pounding the bearings and pistons, falling on its face, and wasting gasoline. The new CVT is a next-generation transmission, controled by the synergy of a combined ECU/TCU/BCU CANBUS "mind" that prevents the unitiated from ruining Subaru's intentions. Subaru wants their vehicles to be pleasant and easy to drive, to get good gas mileage, and be reliable... despite drivers who don't care about such things. Therefore, vehicles equipped with Subaru's latest CVTs accelerate fastest at "partial throttle" as so many have discovered, because, to Subaru, the reliability of the machinery is more important than 0-60. To Subaru, the prevention of destructive ramp rates' effects on the transmission and driveline, and the maximizing of gas mileage are priorities. You can work with it, but you are prevented from damaging it with injudicious use of controls. Find the throttle angle that matches the optimum Ramp Rate and you'll find extraordinary response. Smash the pedal to the metal and you will get the "safe" version to your request. Skilled MT drivers, whether of automobiles or motorcyles, already know these things. Their numbers grow smaller and the people who treat automobiles as appliances grow greater. Technology is simply responding. The transition to CVTs from previous generation transmissions, both MT and AT, came well after another transition that occurred long enough ago that many won't remember it... when fuel injection replaced carburetors. While that transition seems an unrelated event, it was also made in the interests of fuel economy and emissions, just like the CVT. But that long-departed change, while bringing far better driveability, fuel economy, and lower emissions, also created a driveability problem. This problem came not as a result of what fuel injection brought, but what was eliminated... that carburetor itself. The carburetor of old had also transitioned during its use... mainly to accommodate the same issue at work here. With the carburetor gone it seemed that automotive engineers forgot that, or thought that fuel injection was a panacea that cured all. It didn't, it doesn't today, and that missing element the hidden little carburetor embodied was never incorporated into fuel injection systems. That missing element is the separate primary and secondary throttle bores that the engine breathed through... a design augmented by a progressive opening of the far larger secondary bores, compared to the small primaries. The reason carburetors, on small and large displacement engines, were designed this way was to manage airflow during the transition from idle to maximum engine output. No airflow, no power. Wrong airflow, poor power. Et cetera. Again, Ramp Rates due to a varying RPM band managed by transmission capabilities, and driver abilities. This is not too different from what the CVT does today. But instead of bogging down if the throttle was opened too far in the wrong gear on a carbureted engine, the CVT-equipped vehicle's electronics deliver a seamless product that is the best, albeit interpreted, answer. Cars without CVTs, including present generation WRX and STi, for example, still suffer the driver to provide the torque management function despite their state-of-the-art fuel injection systems. There is only one throttle body bore and it's rather huge. Going WOT opens that TB butterfly fully... without the aid of a little primary and progressive secondary like the carburetor has, nor a quick drop in gearing and loosening the engine-transmission coupling that the AT does. Big hole in the intake, wrong rev range selected by the gearbox, heavy vehicle, and the WRX or STi or whatever struggles. During that struggle, incorrect fueling and timing are delivered at crankshaft angles where mechanical leverage fights the oil barrier interface. In worst-case scenarios metal on metal contact will occur, and the driver will have no indication or feedback that their choices were wrong... until they hear that dreaded sound from inside the engine, rod knock. Damage to pistons' ringlands has more subtle telltales, but it is just as expensive a lesson. The CVT and its electronic controls, along with a far better handshaking relationship with the engine's controls, prevents such destructive events. That is a very good thing, and more than a fair tradeoff for the consequential aberrances some experience as undesirable in its actions that do not fulfill their unrealistic expectations, in my opinion as well as, apparently, in Subaru's opinion. Some propose to change the equation with "tuning." They want to bypass the nannying and get their 0-60 fix. It may even happen... but it is guaranteed that such change will show the "why" of the way it is now, with broken drivelines. That is why I'm learning how to get the most from this great transmission, not fault or fight it. Like a growing realization of many, I feel this is the very best transmission not only Subaru has ever made, but a game changer for the future. The CVT will undergo evolutionary changes that will refine it and make it even better, but the revolutionary event itself has already happened.
Here is a rebuttal:
Quote:
There's no can bus obd2 protocol. There are can bus connections you can use via the diagnostic port, but it's not an obd2 can bus. It uses a serial bus signal. That's why any elm323 processor based OBD2 scanner using a T2t connect to any OBD2 port. The same reason why you can't plug an obd2 port to an obd1 port. Or even obd 0. - A lot of cars don't have rev matching on down shifts (most high end cars do) - Busted ring lands and spun bearings? If you over rev, your valves float. You break pistons, sometimes rods. You don't bust ring lands from spinning a motor too fast, you bust them from detonation or no oil and a piston ring catches. Thrust bearings will wear from poor downshifts if you let the clutch out fully and quickly in a low gear and the engine is at idle. And they'll WEAR, not spin. Unless you have a poorly built motor or you run out of oil/beat on your car when the oil is cold, you're not spinning bearings. Regardless, I have yet to see either. I love how he explains about the bearings, but not the ring lands blowing off. - Requested torque is mainly used in bosch and delphi ecu feature. A lot of ecu's don't do this. They use different algorithms to adjust the throttle. Some cars don't even have throttles (I believe s54 motors) bouncing off the rev limiter??? Downshifting over the redline? Bogging the motor? I don't know. Simple solution, know when to downshift, or don't do it, and don't bog the motor or leave it in a low gear. - Ramp rate? Electronic throttles (drive by wire) smooth things out to make everything nice for the driver. Manual or automatic. Cable throttles are obviously a different animal. Once again, I have yet to see someone spin a bearing because they shift retardedly. -"pounding the pistons" ??? Every piston gets pounded. That's why they call them 4-bangers. An explosion is pushing the piston down. The only part of the piston that's contacting anything are the wrist pins and where the piston rings contact the piston in the ring lands. -partial throttle? Data log, the actual throttle position and throttle position requested. I'd love to see the results. -I don't know what this has to do with anything, transmissions and throttles are two different things. The MS3 has a safety where it'll cut the throttle if it thinks the motor is going to blow. My R does the same. -Automatics do the same thing, but they don't have wearable bands like the CVT's. Also most cvt's are still slower 1/4 and 0-60. I remember when nissan switched to one in the altima, the cvt was much slower. Does it work, yep? Will people buy it, yep? But it's not to save the world from manuals and people blowing up their motors.
 
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My motto is CVT: Loathe it and avoid it. It is the primary reason I bought a '12 Accord instead of a '13 and future vehicle decisions will be driven by CVT avoidance for as long as humanly possible.
 
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Originally Posted By: buster
This guy leaves out the fact that some drivers want to be more engaged when driving. Having a computer do all the work is no fun, although that's the way we are continually heading and there is no stopping it.
Don't you just hate the thought of having the computer eventually controlling everything? It's funny how people like myself and others are trying to avoid these technologies and a few others.
 
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Originally Posted By: Tdbo
My motto is CVT: Loathe it and avoid it. It is the primary reason I bought a '12 Accord instead of a '13 and future vehicle decisions will be driven by CVT avoidance for as long as humanly possible.
The CVT is also what put me in a '12, along with wanting to avoid DI. A '13 would have only been a couple of grand more IIRC.
 
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Originally Posted By: hattaresguy
I hold CVT at about the same level as FWD. I'll never buy a vehicle with one.
Problem being that unless you'll settle for a pickup or are willing to spend some pretty long dollars, FWD is hard to avoid and CVTs may soon be as well.
 
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Originally Posted By: fdcg27
Originally Posted By: Tdbo
My motto is CVT: Loathe it and avoid it. It is the primary reason I bought a '12 Accord instead of a '13 and future vehicle decisions will be driven by CVT avoidance for as long as humanly possible.
The CVT is also what put me in a '12, along with wanting to avoid DI.
DI avoidance as well. Although the CVT really put it over the top.
 
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We got my wife a 2010 Sentra with a CVT last year. It's just what she needs. A car that you switch on and drive, and then switch off. I never have to hear that the car is "shifting funny" or anything like that. While many bemoan the fact that cars are becoming more like a "transportation appliance," it's perfect for her.
 

buster

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I find the love/hate for it interesting. Some people absolutely love the new Subaru CVT. Many are folks that drove nothing but MT's for years. Do you think the negative push back is mostly due to it being "new" and "different" in terms of engine response/feel? CVT's are not going away anytime soon.
 
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For me at least, the CVT isn't as much an alternative to a manual, as it is to a traditional automatic. While I have enjoyed many a stick shift in my life, I must admit that they get a little tiresome in daily city driving. For this reason I have went to automatics in my current cars. And my Outback has a CVT. While I have read many negative comments on the Outback discussion board that I visit, except for one particular quirk, I personally enjoy the CVT. Most the negative comments about the CVT that people make on the Outback discussion board are very general. Without ever stating why, the critics simply do not like them. Let me get the negative out of the way first. When cold, the CVT has some hesitation in it. I see this most common when I am accelerating from a dead stop. When my Outback was new to me, I found this very annoying. Since then, I have learned to overcome it by giving the car additional accelerator when pulling away from a stop. I can still feel the hesitation, but it is mostly overcome by this technique. Once the CVT warms up, the hesitation goes away. I have mentioned this to my manager at work, who drives a Murano that also has a CVT. He tells me that his CVT has the very same hesitation. The Pluses. When accelerating, I absolutely love the sensation of constant acceleration without ever feeling a shift point. This it totally cool to me. While modern automatic transmissions have made great improvements in this area, the shift is still very noticeable. Some may say it isn't in their car, I personally feel it is because we become so accustomed to the shifts that we tune them out. The other advantage to the CVT is fuel efficiency. It is an improvement over an AT, and in all but the most experienced driver, the CVT also gives an improvement in efficiency over a MT. I'm hoping that by the time I buy my next car the hesitation has been fixed in the CVT. But, I will definitely consider a CVT again.
 
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Originally Posted By: Tdbo
Originally Posted By: fdcg27
Originally Posted By: Tdbo
My motto is CVT: Loathe it and avoid it. It is the primary reason I bought a '12 Accord instead of a '13 and future vehicle decisions will be driven by CVT avoidance for as long as humanly possible.
The CVT is also what put me in a '12, along with wanting to avoid DI.
DI avoidance as well. Although the CVT really put it over the top.
Add me to the DI and CVT avoidance list. hide I don't mind the slight hit in FE or HP, I'll live happily without it.
 
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Originally Posted By: fdcg27
Originally Posted By: hattaresguy
I hold CVT at about the same level as FWD. I'll never buy a vehicle with one.
Problem being that unless you'll settle for a pickup or are willing to spend some pretty long dollars, FWD is hard to avoid and CVTs may soon be as well.
You are spot on here. Sports cars, which have traditionally had a MT, are now going to dual clutch automatics, which are heavily computer controlled. Even BMW, who 20 years ago was known as being the holdout in stick shifts, with almost 70% of BMW's being built with a MT, now sells very few cars with a traditional MT. Really, fewer pickups are being offered with a MT. Most people that buy a truck want it to be capable of towing. And the MT just isn't suited for towing. Give it another 5 years, and I doubt you will be able to find a MT. It will all be CVT, dual clutch AT, or whatever is going in hybrids.
 
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Why does the CVT have to be so complex? Anybody who has ever ridden a Honda CH80 (and there are a lot of them, they made them for nearly a quarter of a century)knows how a CVT should work. Crank the throttle to the stop and it holds the engine at peak torque for as long as it can. (depending on whether or not the owner has messed with the roller weights)It's weird to look at the speedo climbing but to hear the same engine note. It works and does so with 0 electronic management. You want maximum acceleration? You twist the right grip until it won't twist anymore. The only people that are breaking things on Elite 80 motors are people that neglected to drain and add a 1/2 qt of decent motor oil every 1000 miles or so. (which does seem like a short OCI but it takes awhile to go 1000 miles when you can only go about 45mph.)
 
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Twenty years ago, stick Hondas were common on dealer lots. They're now a rarity. If very few buyers want sticks anymore, then very few will be built and they'll gradually fade away entirely, certainly within a decade. I used to consider a stick to be a real car with the automatic a lesser version. Few seem to think that way any longer. CVTs do have the potential of greater reliability and lifespans than conventional auotmatics. They should also be fairly cheap to produce as compared to conventional automatics.
 
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Originally Posted By: buster
I drove a 2014 Forester with the CVT and it wasn't bad.
"The problem is twofold but starts with the transmission, a CVT that displays all the worst qualities of these units. We’d take the four-speed from the old RAV4 over this thing. Heck, we’d even take a two-speed Powerglide. The Subaru CVT tricks your ears into believing the Forester has good throttle response, but the accelerator pedal is about as nuanced as a light switch. Stomping on the gas yields no surge of power, just a rush of revs and noise from the engine. Without steps in the gearing, like those in the CVT that Subaru uses with its more powerful engine, the Forester drones away even as it makes sluggish progress. It finished dead last in acceleration testing, doing zero to 60 mph in 8.6 seconds and turning in a 16.7-second quarter-mile." http://www.caranddriver.com/comparisons/2014-subaru-forester-25i-touring-page-2
 
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Originally Posted By: BHopkins
Originally Posted By: fdcg27
Originally Posted By: hattaresguy
I hold CVT at about the same level as FWD. I'll never buy a vehicle with one.
Problem being that unless you'll settle for a pickup or are willing to spend some pretty long dollars, FWD is hard to avoid and CVTs may soon be as well.
You are spot on here. Sports cars, which have traditionally had a MT, are now going to dual clutch automatics, which are heavily computer controlled. Even BMW, who 20 years ago was known as being the holdout in stick shifts, with almost 70% of BMW's being built with a MT, now sells very few cars with a traditional MT. Really, fewer pickups are being offered with a MT. Most people that buy a truck want it to be capable of towing. And the MT just isn't suited for towing. Give it another 5 years, and I doubt you will be able to find a MT. It will all be CVT, dual clutch AT, or whatever is going in hybrids.
Yeah, virtually all the Porsches coming in to my shop are PDKs. Porsches used to be so simple electronically. I could install a Porsche in 15 minutes. Not so much anymore. They may have actually surpassed Audi in inaccessibility and redundancy. The Porsche Cayenne Hybrid is the first and only vehicle that I have not been able to install on. I went over the schematic with a Porsche tech and it looked to us like you would have to go into the 288 volt system. I am not messing around with 288 volts DC.
 
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Saying that a MT is not suitable for towing is ridiculous. You either have never done it or didn't do it right. The old Cummins Ram and Power Stroke Super Duty with the MT were awesome tow rigs. I had both and I miss them. I won't even bring up the big rigs with their transmissions...
Originally Posted By: BHopkins
Originally Posted By: fdcg27
Originally Posted By: hattaresguy
I hold CVT at about the same level as FWD. I'll never buy a vehicle with one.
Problem being that unless you'll settle for a pickup or are willing to spend some pretty long dollars, FWD is hard to avoid and CVTs may soon be as well.
You are spot on here. Sports cars, which have traditionally had a MT, are now going to dual clutch automatics, which are heavily computer controlled. Even BMW, who 20 years ago was known as being the holdout in stick shifts, with almost 70% of BMW's being built with a MT, now sells very few cars with a traditional MT. Really, fewer pickups are being offered with a MT. Most people that buy a truck want it to be capable of towing. And the MT just isn't suited for towing. Give it another 5 years, and I doubt you will be able to find a MT. It will all be CVT, dual clutch AT, or whatever is going in hybrids.
 
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Originally Posted By: demarpaint
Don't you just hate the thought of having the computer eventually controlling everything? It's funny how people like myself and others are trying to avoid these technologies and a few others.
Nope, I quite like it. The computer will shift faster and perfectly every time whereas I cannot. The computer will make sure the shift points are at maximum power (where torque/hp cross) for maximum acceleration, I will not. The computer will make sure the tires don't spin so I accelerate faster, I cannot. One of the things I love about the SHO is that rain or shine plant the gas and point her in a direction and she goes like stink. For the times I want to "Row my own", I can pop it into Manual mode and come close enough. I do like driving stick though but there is something to be said about a modern automatc, be it a CVT, DCT, or a regular old unit. And I sure don't miss adjusting a choke 2x a year or any of that nonsense.
 
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Originally Posted By: fdcg27
Twenty years ago, stick Hondas were common on dealer lots. They're now a rarity. If very few buyers want sticks anymore, then very few will be built and they'll gradually fade away entirely, certainly within a decade. I used to consider a stick to be a real car with the automatic a lesser version. Few seem to think that way any longer. CVTs do have the potential of greater reliability and lifespans than conventional auotmatics. They should also be fairly cheap to produce as compared to conventional automatics.
Being a Honda guy myself, I agree with you 100%. A manual can also outlast everything else on the car as long as it's shifted properly.
 
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Call me old fashioned but I still like the 4L60E coupled with a 3.73 rearend. I loath the GM 6-speed truck tranny.
 
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