The EPA rating for the Mustang GT V8 convertible is one less than the V6
convertible, both city and highway. As to the V6 and V8 coupes they are one
less than the convertibles.

My one son has two '08 coupes, a V6 and a V8. In the real world, if you
live in a mountainous area like we do, his V6 coupe averages TWO miles LESS
than the his V8 coupe. Like it says on the label "Your mileage may vary."


"C. E. White" <cewhite3@removemindspring.com> wrote in message
news:48ea419a$1@kcnews01...
>
> "I M" <nowizer@webtv.net> wrote in message
> news:18670-48E7E564-1044@storefull-3253.bay.webtv.net...
>>
>>
>> does the EPA actually road drive cars to establish mileage
>> estimates....or is it it done in the lab on a dyno?
>
> It is done in the lab on a dyno. I doubt they are not making any allowance
> for top up / top down. I assume they do the testing using the CD for top
> up. See http://www.fueleconomy.gov/feg/how_tested.shtml . For the Mustang
> there are not separate listings for convertibles and coupes. Toyota does
> list the Solara convertible separately from the coupe, and the convertible
> gets 1 mpg lower highway mileage. I assume this is a result of the
> convertibles heavier weight and higher CD. Another example would be BMW,
> they list convertible and sedan models separately. The 135i sedan gets 1
> mpg better city mileage. This is almost certainly because it is lighter.
>
> Ed
>