78CobraII said:
Vicki,
The "MPG" option would be a good one to research. I've never understood what the difference was between regular 2.3L cars and those with the "MPG" option.
For example, I have a '76 hatchback with a 2.3L, 4-speed, and a 2.79 rear axle gear. Mustang II's don't get much more economical than that, but it wasn't an "MPG" model!
I found some ads on the .NET site that show 34 miles per gallon for the "MPG" option. It shows a 2.3L engine, 4-speed, and 3.18 rear gear with the "MPG" option (3.40 for California!?). This implies that the "MPG" option is using the smaller 6 3/4" rear axle rather than the 8" rear in mine. Of course mine NEVER got more than 20 miles per gallon either!
The Ford options sales book for 1976 would probably answer this question.
It's not so much what your Mustang had in common with the MPG models that made it similarily economical, but what it didn't that kept it from being an MPG model. While all three Pinto body styles were available with the MPG package, few actually got it due to the options that were not available, including the following: 2.8 V-6 engine, A/C, PS, AT, optional axle ratio, rear window defroster.
In other words, the MPG models were literally stripped to the bone, and basically made available as a marketing tool for Ford to market againt the Chevy Chevette. Placing these restrictions on the car allowed Ford to market it at $2895, which made it the lowest priced car in the US at the time.
There were some cosmetic differences as well for CA models, which included some chrome mouldings and bezels that were seemingly not available on (later) 49 state models.
As for the Mustang MPG's, (as Sal stated), there isnt nearly as much info about them, by comparison. It's my guess, that since Mustang was marketed differently than Pinto, there would have been fewer of them ordered as MPG models. Whether the Mustangs had all of the same (or other) ordering restrictions on them, I can't tell based upon the information I have. I do know however, that the auto trans was an option on the MPG Mustangs but not Pintos, (ex wagon), and (hard to believe) the MPG option WAS available on the Ghia models as well....(this could explain why).
I believe your comments about the use of the 6 3/4 rear axles are right on target. For what I can tell and recall, the 3:40 ratio was a CA only option in both the 6 3/4 and the 8" rear. However, manual equipped cars with this ratio were not available in conjunction with 2.8 6cyl engines...at least on Pinto's. But strangely, they seem to be on similarily equipted Mustangs as (optional).
As such, it would seem that the majority of cars that got the 8" rear and the 3:40 gearset would have been 6cyl cars with auto trans...probably why most of them are found in Pinto wagons...the exception being the few V6 Mustangs stared above. Most regular Pintos (including 4cyl equipted wagons) got the smaller rear, as did most of the 4cyl Mustangs with either the 3:00, 3:18 or 3:40's.
Nowhere have I been able to find conclusive evidence that states or indicates V-6 cars were only available with 8" rears, but it seems likely (as with all V8's)... with type of transmission (or CA models) being the only possible factor(s) that might determine otherwise in some cases.
