'84 CFI 5.0 gets 30 MPG?!? WTF?

[Darkwriter77]

I wonder where the hell these people are getting their MPG statistics. Since the EPA's website for MPG numbers only goes back to like '86, I dug around until I found a site that lists mileage stats for an '84 Mustang. Lo and behold, I came up with this...

http://www.mpgomatic.com/2008/06/24/ford-mustang-gas-mileage/

While the more recent listings sound a lot more believable in the mid- to low-20's, and I can almost believe that the four-banger Foxes in the late 80's got close to 30 ... HOW the HELL do they figure an '84 CFI 5.0 (transmission listed as "A4," the CFI 5.0 was the only Mustang to get an AOD in '84) will get 30 MPG on the highway? The city rating of 18 MPG sounds a bit optimistic, but ... 30 for the highway? HOW? ... especially since the CFI-AOD cars came with 3.27 gears!

I don't get it. Maybe I should reconsider doing that carb swap, after all...?

 

[GTOreturns]

Before I modded my 93 5.0 I was getting 25.

 

[Darkwriter77]

Mid-20's I can believe. I got 23 MPG in my '86 GT 'vert with an AOD. But 30 MPG? Especially considering the '84 CFI has to breathe through a Y-pipe that cuts down into a single 2.25" cat? That just seems nuts. If anything, I would've expected it to get more like 18 MPG highway, and like 14 MPG city...

 

[QUICK91LX]

The "A4" just means Automatic 4-Speed. If it was a T5, it would read "M5" for Manual 5-Speed and I would double check that all CFI/AOD cars had 3.27's, I could see one with 2.73's on a long trip on flat roads in good weather could get near 30, but I wouldnt hold my breath waiting for someone to achieve it

 

[Mustang5L5]

They measured MPG differently back then.


Today's standards are even tighter, so fuel economy today is more realistic of what the vehicle would do. But 20-25 years ago, it was looser.

 

[Darkwriter77]

They measured MPG differently back then.


Today's standards are even tighter, so fuel economy today is more realistic of what the vehicle would do. But 20-25 years ago, it was looser.

So basically ... it's more like, 30 MPG is theoretically possible ... if you're going down a really, really long hill ... with a tailwind.

 

[Black1987Stang]

They measured MPG differently back then.


Today's standards are even tighter, so fuel economy today is more realistic of what the vehicle would do. But 20-25 years ago, it was looser.

and I seen on a show somewhere they get the mpg from running the car on a dyno WTF they couldn't even go out in the real world and get real world times? especially on the highway .....which won't take in effect the wind speed, aerodynamics, tire pressure, etc.

Since they call it the "Estimated MPG" that must be how they can get away with the higher than actual mpg's

 

[RsStanG1987]

Ive had close to 30mpg on the highway in my stang.

 

[5.0Torx]

i did high 20s with a best of 31 in my 5.0 this past summer on a 2000 mile roadtrip.

 

[aaros]

i get high twentys, sometimes better, with my vert with 2.73's.

 

[QUICK91LX]

The new way that they rate mpg is supposedly more realistic, but has shown to come out lower than many average driving situations, at least around here. my old zx2 was rated at like 22/28 or something under the new system and I got 28 in mixed driving and up to 36 when i ran mostly highway...so how "real world" are the new methods? i think they are very flawed. where i work at toyota, under the new system the prius was rated at 61mpg city. i live in the country, lots of 2-lane 45-50 mph roads with some towns and lights. people came to us complaining they were only getting 45-50. they didnt realize that the 61 number is possible, but in very city-type stop and go driving where the electric motor does most of the work, not where we live or on the highway. now they have revamped the ratings, though im not sure how accurate they are

 

[Darkwriter77]

The new way that they rate mpg is supposedly more realistic, but has shown to come out lower than many average driving situations, at least around here. my old zx2 was rated at like 22/28 or something under the new system and I got 28 in mixed driving and up to 36 when i ran mostly highway...so how "real world" are the new methods? i think they are very flawed. where i work at toyota, under the new system the prius was rated at 61mpg city. i live in the country, lots of 2-lane 45-50 mph roads with some towns and lights. people came to us complaining they were only getting 45-50. they didnt realize that the 61 number is possible, but in very city-type stop and go driving where the electric motor does most of the work, not where we live or on the highway. now they have revamped the ratings, though im not sure how accurate they are

How does this "new rating" on MPG work, exactly?

I was reading the other day that they say a more "accurate" way to measure fuel economy is to actually in gallons per mile, X 1,000 or something like that. That is, for every 1,000 miles, you figure up that your car used X amount of gallons. I dunno, I don't see the point in it. Sounds kinda like some math guru trying to unnecessarily complicate things, to me. I think what they were getting at was to try to convince people to use their less fuel-efficient vehicles for the long hauls on the highway, and their econo-box cars for in-town driving as a means of OVERALL conserving more fuel. Or something. And stuff. Um, yeah.

 

[QUICK91LX]

www.fueleconomy.gov there is a video i just watched that sorta explains it...

 

[Mustang5L5]

So those 91-93 dual plug 4-bangers get 30MPG??

Hmm, maybe i should look into one for a beater since i'm doing 55 highway miles/day.

 

[Darkwriter77]

I would consider one, myself, but I'm doing pretty damned good DD'ing Stinky, already, and I've been using the hell outta that truck bed over the past month.

 

[trbkrb]

Plus you have to consider the max speed limit was 55 back then. The good ole days! LOL!

I got right about 30 MPG in my 87 LX a couple of times on trips from Houston to New Orleans in the late 80s. 360+ miles and I used right over 12 gals. 55-60 MPH with 2.73s and little or no AC.

 

[Darkwriter77]

Not doubting that others have attained 30 MPG with THEIR 5.0's, as I know it can be done with the right setups and driving habits. But given the particular stock arrangement of my '84 with 3.27's, an AOD, crappy-designed CFI, and a seriously choked-up exhaust system, getting 30 MPG (or even 25 MPG) seems unrealistic as hell.