I think you're way off in your numbers...You can't just compare pure gear ratios between ATs and MTs, and then toss in pure drivetrain loss...remember the torque convertor also is multiplying torque, not just the gears themselves. Ever wonder why the gearing of the ATs are lower (numerically) than an MT? It isn't to handicap them, thats for sure...otherwise designers could easily make them use the same ratios. The reason is the torque convertor is doing quite a bit of work in addition to the gears. So you don't need the steeper ratios mechanically as you do w/ the manual. And reports are that the AT Fits are just as quick off the line as an MT.

Everything else you've said about the AT's greater weight and overall drivetrain loss is correct. But not about torque multiplication.

I'll add this link for those who want to read up on AT basics: http://auto.howstuffworks.com/automa...ansmission.htm

Also this one for the torque convertor: http://auto.howstuffworks.com/torque-converter.htm


An AT is an entirely different animal than the MT.

 

That looks suspiciously to me like you are thinking of torque convertors and conventional automatics.

I am talking about CVT and the CVT in my Jazz doesn't have a torque convertor. It has a clutch. The same article that tells us that (which I linked to earlier in this thread) also states that the CVT transmission is at most 2% less efficient than a manual (in terms of power loss). It seems possible to me that you can mak up that 2% simply by always being in the 100% correct gear.

As regards wheight the CVT gearbox is simpler and lighter than a manual gear box (it's only two pulleys and a belt after all).

I don't doubt for a minute that a conventional auto is poor compared to a manual. I wouldn't touch a conventional auto with a bargepole because they are so wasteful. But CVT is different.

 

You obviously aren't very up to date with the technology here. You can get CVTs on a 2.5l sports car now and as I have mentioned several times a CVT was put in a Williams F1 in 1993 and performed flawlessly. In any case I didn't say that a CVT in any car was better than a manual gear box in any car. That would be stupid. A manual Ferrari is always going to perform better than a CVT in a mini, ffs.

What I am arguing is that if you take the same car and swap it's manual box for an equivalent CVT (as you would if you were donig it for sporting reasons) the CVT equipped model will perform better. It might not be ideal for all sports but in a pure racing sport with plenty of acceleration/deceleration like F1 everything I've read on the web tells me it would be better.

don't be silly. The FIA doesn't decide to ban something for the hell of it. As you actually wrote earlier they have good reasons for doing it. They also make a big, big thing about innovation (or used to until the costs began to spiral). That's why F1 teams generally build their own vehicles. There's no standard chassis, or standard engine that everyone gets given unlike Indy cars.

The inner details of engines are not that closely specified. The number of cylinders and capacity are along with the wheight but that's about it. If you think that a Honda F1 engine is anything like a Ferrari F1 engine then you know nothing about F1.

Yes..or they could be. David Coulthard drove one back in 1993. That was 13 years ago. Given how incredibly simple they are internally the development costs are low.

Huh? What are you on about here? I really don't fathom that argument at all.

Are you saying that CVT would be so powerful they couldn't handle it?
Or that having a car accelerate in a predictable, linear way with no loss of traction/power/stability during a gear change makes life harder?

 

I was'nt talking about the CVT in a Jazz, I was talking about the 5speed auto that the USA Fits get stuck with.

When the torque converter is slipping its hard to compair to a manual. When the torque converter is slipping it multiplys torque, sure, but when it's locked up it doesnt.
Gearing can do two things, it can sacrifice speed for more torque, or sacrifice torque for more speed. With a car transmission, it sacrifices speed for more torque. The automatic is geared higher then the manual, therefor it multiplys torque less. This is why your reving higher in fifth gear in the manual then you are in the automatic when going the same speed. You cant multiply torque as much with the auto as the manual and be reving lower, it doesnt work that way.

As long as the torque converter isnt locked up, it plays tricks on you, so its hard to compair gear ratios.

As for an automatic launching as quick as a manual, I think traction has more to do with launching then anything.

The automatic Fit takes two and a half seconds longer to go 0-60mph then a manual Fit. This is because of the added wieght, drivetrain loss, and the higher gearing.
If the automatic were to use the same gear ratios as the manual, then the automatic wouldnt be as slow.

whatever, you dont buy an automatic Fit if your concered about performance anyway.

 

I don't think you buy a Fit at all if you're all that concerned with performance.

 

When it locks up, the need for torque multiplication disappears...because you most likely have completed your acceleration run, and are now cruising...at which point, most often, the AT is using 4th or 5th gear, which mathematically reduces torque, as they are overdriven.


Agree w/ everything except the gearing. If we leveled the playing field (reduced AT car's weight, & increase HP by about 10) and let the gear ratios be the only difference, I think you'd see they would be very close. I'm betting that the AT's total torque multiplication, factoring in the converter, is close or more than the MT...but the MT car has the weight and power advantage so we'll never know. Also, the converter torque multiplication is likely not linear. There are several variables involved, but w/o the lockup clutch, a converter usually will always be slipping at least a small amount.

I think we both agree that gearing needs to be sized effectively to take advantage of available engine torque and also desired driving characteristics. In my old Mustang (3 spd auto) I used to laugh at 'ricers' who would be shifting 1-2 and 2-3 all while my car finally reached the end of 1st. I could keep up and out accelerate most of them because my engine had so much torque to begin with...it didn't necessarily need (though it could have benefited from) taller gears...when you increase the gearing ratios (numerically) it is always advantageous to have more gears to use (close up the ratios), especially with a narrow power band. That is why I was OK with buying an AT Fit, because it has 5 gears. With such a small engine, I need at least 5 or 6 gears to take advantage of the torque curve.

 

OK, Im not going to argue with you. I'll admit I dont know as much about automatic transmissions as you do. I learned something from you. OK, Now I agree, a manual is quicker then auto because thier lighter and has less drivetrain loss not because of gearing.

Hopefully soon, none of this would matter because all the regular automatic transmissions will be replaced by CVT transmissions. But I really dont care, because I will never buy another auto again, aslong as manual transmissions are around.

 

Unless I am wrong,(that's possible)Ryotto's response was by way of an explaination for why the usa fit seems to drive so drastically different than the manual.(which makes sense to me).AS a new member and new owner I came to the forum and to fit talk and behold I saw a post that began with one mans long reveiw and preference for the usa auto fit.little did I realize that 200 posts later the conversation had turned to cvts.Of which I have only test driven in the nissan versa,I must as an aside say I never drove Any automatic that has driven like that car,it was an epiphany of sorts.If it had been offered here in a fit I would probably have chosen it.It is not offered here and the choice here in the usa for now is automatic/manual/auto with paddle shifters.I think its a shame that due to the popularity of the car ,and the capital incentive of making a sale,allotments don't hang on the lot long enough for people to test drive and compare.compelling some to preorder undriven a car,they may be incompatable with.When the thread began the long review may well have influenced a buyer who came to the forum for information assisting an educated guess as to which fit to order(in the US)All the numbers and calculations of gear ratios and torque,illuminate the test drive experience,but do not I think eliminate its need.As the differences of opinion on this thread testify there are people who are drawn distinctly to one or other.

 

Ryotto, not trying to argue, just so you know. Some folks just like the mechanics of shifting, and I personally enjoy driving a stick...so don't anyone think I'm an AT nut. But the AT normally gets a bad rap from a lot of ppl who don't realize that an AT can be made to perform every bit as good as an MT, if not better. But of course this comes at a cost. THere are lots of muscle & sports cars w/ ATs, and many times drag racers use ATs exclusively. They can be built to handle gobs of power too (thinking here of american ATs like the C4, powerglide, etc).

The Fit's AT is a very peppy transmission, with crisp shifting and good response. How long it lasts, who knows. How much power can it handle? Who knows. But do realize the technology has greatly improved and will continue to evolve...I've not yet driven a CVT. Sounds interesting though.

 

GO for AUTO fit.. the original FIT that out in japan is AUTOMATIC..

and HKS and TOPFUEL only make TURBO charger for AUTO fit only

 

im glad they didnt bring the cvt here ... my cousin in Hong kong said they were so many problems with the CVT... glad i got the 5at

 

Funny, flawless isn't exactly how your article puts it. Maybe you should your sources more carefully.


It's really easy to act like you've got a point when you're making up my side of the argument. Unfortunately for you I'm one of those annoying people that's going to point out the fact that I never said what you want to argue against.


It seems that plenty of others disagree with you. Why doesn't Ferrari offer a single CVT vehicle? They strike me as a company that is very much interested in selling cars with better performance than the competition.


Why were turbos banned then? More importantly why are they talking about bringing them back?

The fact is that F1 does whatever it wants to do at any point in time for whatever reason they want.

Actually you've already conceded the point you were trying to make about knowing why they banned CVTs so I have no idea where you're trying to go with this now.


Again, making up my side of the argument isn't going to get you anywhere. I'm not saying what is the same or different between Honda and Ferrari F1 engines at all.

The point is that F1 is one of the most tightly regulated motorsports, and excluding ones where the parts are supplied from the same entity, probably the most tightly regulated of them all.


There's nothing at your local shop that handles 800hp at 19kRPM all day, let alone a transmission. Every single aspect of these vehicles is prohibitively expensive.

Developing such a CVT from scratch may or may not be more expensive than developing a traditional F1 transmission, but that's not what you're up against. It will certainly be more expensive than adopting last year's transmission to this year's requirements and improvements, and that's the real delta that teams would be facing.


No. Pretty simple claim here, not sure how you're not getting it. Driving an F1 car is going to be hard no matter what. You're theorizing that a CVT will make it too easy for the sport to remain a spectacle. I disagree.

 

lol.. Honda jazz in HK.. is most of them is NON vtec.. which is using Steel Belt CVT..

the VTEC CVT using Chain (what they use on NISSAN MURANO n MINI COPPER S) they very hard to snap/broke.. ...

 

There must be a lot of forums, which are full with articles about broken CVT,s in HongKong!
But, searching for a quite some time, I actually couldn’t find any?!
Maybe you or your friend there can help me to find them!

 

i think more ppl in HK use newsgroup u may have better luck finding them there ..... if u read chinese

 

All around the world, (except in northern America) Honda sells the Fit/Jazz automatics whit the CVT.
If I consider all the Asian countries, where the percentage of automatics is much higher then in Europe or USA, there should be some 100’000 of these gears in action.

It sounds amazing that there should be only in Chinese speaking countries problems with this gear.
If you really search the net you will find problems with CVT gears, but they are usually from other brands like Ford, Subaru, Fiat and even AUDI!
Most of them are quite old threads.

And yes, I did also find one Honda with a broken CVT after 309’000 miles!!!

Well, there could also be the possibility, that Honda did really pack all the trouble CVT into the Chinese cars, ore it really happens only to Chinese speaking Hong Kong peoples!

 

i never said every fit cvt had problems there, but from what i heard for its problems and for myself even if the cvt was perfect i still prefer conventional at... never liked cvt never will

 

In fact, that is what I always hear about the CVT, … so many problems, … so many problems, … bla, bla, bla.
They must be so extremely genius hidden in the Jazz/Fit that everyone can hear them, but it seams, nobody can find them.

I don’t care whether you like CVT’s or not, for what reasons ever, but if you put a statement like the first one, the bla, bla, bla about the CVT will never stop!

 

It is just about 5000 miles (7977km) now and I can’t complain about the mileage.

Average for the 5000 miles = 6.015 l/100km (it’s the way we count in Switzerland)
= 16.624 km/l = 39.101 mpg (US) = 46.960 mpg (Imp.)

Best tank filling = 5.63 l/100km
= 17.761 km/l = 41.774 mpg (US) = 50.171 mpg (Imp.)

Worst tank filling = 6.657 l/100km
= 15.022 km/l = 35.334 mpg (US) = 42.436 mpg (Imp.)

The worst tank was during wintertime, with AC 100% switched on.

I can’t complain about AT either :-)

 

In response to your mileage claim for the Fit in Europe, it should be noted that the numbers you state are for imperial gallons. Converted to U.S. gallons your average mileage is not 45 MPG it is really on 38 MPG (per U.S. Gallon). Still njot bad for an auto tranny.