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Old April 12th 11, 01:05 PM posted to rec.autos.tech
C. E. White[_2_]
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Posts: 617
Default Automatic vs. Manual transmission

According to www.fueleconomy.gov, 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
http://en.wikipedia.org/wiki/Dual_clutch_transmission.

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




"SBH" > wrote in message
...
> 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?
>



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