It's been well known a manual transmission obtains better fuel mileage than
an automatic. My sister is preparing to purchase a Ford Fiesta and wants a
manual, mainly for the fuel savings. The sales guy indicated the new
transmissions (more so the 6 speed auto in the Fiesta) are better and more
fuel efficient than manuals. Anyone know if this is true?
Yep, The computer know how to shift the trans for economy better than
you do. The only reason that older autos were worse than a stick was due
to the slippage of the converter and the lack of close gearing. New
trans have lock up, better gearing, better overall gear ratios and the
computer controls make them work much better than a stick.
lots of people know the answer to this. you could too if you could be
bothered to look up the numbers on the manufacturer's website.
you'd be better off asking the question "why" - if you don't want a
"rtfm" answer.
In many cases, the automatic is at least as economical as, or sometimes
better than, the manual. The difference is not worth the worry. And
dats the truff, babe ruff.
Silly me, why didn't I think of that....? Oh wait, I did, but that doesn't
erase my skepticism about manufacture mileage posting. It's similar to the
little guy enhancing the size of his johnson because it really isn't.
Therefore, I thought I'd bother myself twice and ask in here as well. You
know what they say about assumptions.
The new Ford 6 speed auto has no torque converter. It uses a computer
applied clutch to start and shifts between two clutch driven gear
trains that change the ratios- one for odd, one for even gears.
I wonder how the clutch life will be.
, the "regular" automatic Fiesta is rated 29
city / 38 highway. The "regular" manual Fiesta is rated 28 city, 37 highway.
The SFE Fiesta, which has the automatic, is rated 29 city, 40 highway.
Interestingly, both the regular Fiesta automatic and the SFE Fiesta
automatic have a combined rating of 33. The regular manual Fiesta has a
combined rating of 32.
So, at leat in the government mandated tests, the automatic does get better
fuel economy than the manual. The fueleconomy.gov website allows individuals
to post fuel economy estimates. The individual estimates for the manual
transmission model Fiestas are higher that for the regualr or SFE automatic
versions (36.7 for the manual, 34.7 for the regualr automatic, 32.5 for the
SFE automatic). These are "personal" estimates, so take them with a grain of
salt.
Consumer reports tested both manual and an automatic versions of the Fiesta.
In the CR testing the overall mileage for the manual was 32 vs 33 for the
automatic. The manual got 39 mpg on the CR 150 mile trip. The automatic got
41 on the 150 mile trip. For CR the manual averaged 23 city, 42 highway. The
automatic averaged 22 city and 45 highway.
Be aware that the Fiesta automatic is not a traditional automatic. It is a
sort of computer shifted manual transmission. It is a dual clutch
transmission and unlike traditional automatic transmissions, it does not
have a torque converter. See
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I have a 2011 Fiesta with an automatic. So far in my normal sort of driving
I am averaging just short of 36 mpg. I don't get a lot better on a long trip
(maybe 38 or so) but then I don't get much worse around town. I bought a
regular automatic Fiesta (not the SFE). The SFE model costs about $600 more
and although it has a higher highway rating (40 vs 38), the in town and
combined ratings are the same as the regular Fiesta. According to the Ford
salesman (not exactly an expert in my opinion) the SFE has additional
areodynamic features that allow it to achieve the higher highway ratings. I
doubt this (I didn't see any dramatic differences). I think it had more to
do with the tires (the SFE has different tires) and possibly the
transmission shift programming. I drove both and didn't really see much
different in performance between the two.
Ed
I imagine it will be very good. It doesn't use the sort of clutches used by
a manual. It uses stacked clutch packs that are hydraulically activated. I
have a farm tractor with this sort of transmission. After 20 years of hard
use it is still just fine. And remember "traditional" automatics also
include clutches that are activated hydraulically. No reason to think the
clutches in the Fiesta "automatic" will be more failure prone than those.
Ed
In Europe, Ford currently offers a PowerShift transmission in the Ford
Focus. This PowerShift uses a twin wet-clutch system to handle the
higher torque levels of the 2.0-liter TDCI engine available in the
Focus.
In North America, a dry-clutch derivative of Ford?s PowerShift
transmission will be used for added efficiency and durability. A dry
clutch transmits power and torque through manual transmission clutch
facings, while most automatic transmissions utilize wet clutch plates
submerged in oil. As a result, the dry-clutch PowerShift transmission
does not require an oil pump or torque converter, providing superior
mechanical efficiency.
?A dry clutch is a real sweet spot for lighter vehicle applications,?
said Piero Aversa, manager, Ford Automatic Transmission Engineering.
?PowerShift is more efficient, it saves weight, is more durable, more
efficient and the unit is sealed for life, requiring no regular
maintenance.?
PowerShift, unlike conventional automatic transmissions, does not need
the heavier torque converter or planetary gears. In addition, the
dry-clutch derivative eliminates the need for the weighty pumps,
hydraulic fluids, cooling lines and external coolers that wet clutch
transmissions require. As a result, the dry-clutch PowerShift
transmission can weigh nearly 30 pounds less than, for example, the
four-speed automatic transmission featured on today?s Ford Focus.
Well so far my experiences with the Fiesta automatic have been positive. It
is not quite as smooth as the AW 6 speed in my old Fusion, but better than
the AW automatic in my SO's RAV4. The only oddity I've noticed is the hill
holder "feature." Works OK, but feels "different" than a traditional
automatic. But it is much better than starting up a steep hill with a
traditional manual.
Ed
It depends entirely on who is driving. Some of the computer controlled
automatic systems are very, very good and probably better than the average
driver.
However, when those systems break, nobody really knows how to repair them,
whereas rebuilding a manual (even a transaxle) is something you can do in
the backyard.
--scott
Who knows if the manufacturers are telling the truth about the fuel
savings. I haven't met one person that gets the mileage that was
posted on the sticker from the factory. Believe them if you want.
anyone saying this stuff is hard to repair is the same kind of luddite
that said that about fuel injection 30 years ago. now we laugh at
injection luddites, not only because injection systems are simpler to
repair, but because they're much more reliable.
that's not true. look at one of these 6-speed dual clutch systems -
apart from the electronic control module [which i hope you don't think
is any less reliable than an injection computer], it's no more
complicated than a traditional stick. /way/ simpler than a traditional
auto with its hydraulic analog computer, pumps on input and output,
multiple actuators and multiple clutches. if you can't handle just two
clutches and a few electronic solenoids, you've got other problems.
I did a short review of those just now. I don,t know what the fuss is
about. In my 2001 cavalier I have got 34 mpg doing average of 65 mph
up and down hills. On the flat I should get minimum of 36 mpg doing
55mph, Mabe more. My chevy has a 4 speed, but hear a 5th noise, maybe
lockup.
Greg
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