MPG on bullet birds?

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jonecin

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Joined
Sep 30, 2009
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What kind of gas mileage are you all getting on your bullet birds? I'm running a freshly rebuilt 390 with edlebrock 4 barrel and Im only getting about 6-8mpg city and 8-10 hwy. It's real real bad. I've always had classic cars (my third) so I understand they come with a price at the pump but I was expecting 12-14.
I love this car and just want to drive it as much as possible without going broke...

The cars I had in the past:
67 mustang with 289 was getting 16mpg
73 Lemans GM350 14-16mpg
 
If you want better gas mileage yank the 4 barrel and run it with a 2 barrel...... You should see at least 10 - 11 mpg with a 2 barrel.

I've found that the best way to get good gas mileage is to keep my foot out of it. Unfortunately I've never gotten good gas mileage! ;)

John
 
The 390fe forums say headers improve gas mileage. I am going to try that and see if that helps. I get 9 to 11 with a autolight 4 barrel (stock) carb. Good luck.
 
Rooky

jonecin said:
What kind of gas mileage are you all getting on your bullet birds? I'm running a freshly rebuilt 390 with edlebrock 4 barrel and Im only getting about 6-8mpg city and 8-10 hwy. It's real real bad. I've always had classic cars (my third) so I understand they come with a price at the pump but I was expecting 12-14.
I love this car and just want to drive it as much as possible without going broke...

The cars I had in the past:
67 mustang with 289 was getting 16mpg
73 Lemans GM350 14-16mpg
Click to expand...

I run a '56 and a '61 here in the UK, the '61 which is my second convertible owned returns between 8 - 16mpg depending on driving habits (heavey right foot) my first '61 which had a blue printed engine with two four barrels didn't achieve any better than 10mpg, as to the the '56 which is the 312 variant it does pretty good between 15 - 22mpg.
Headers do make a small difference but the cost at $1400+ doesn't make economic sense the two barrel route has the same constraints the costs of the manifold and the carb, so some what the same as headers.
My thoughts on the subject is 'if you buy these cars don't expect motoring to be cheap'.

I pay £4.95 per gallon here, at $1.61 to the £1 just less than $8 per gallon.
 
hi, new to the forum. $850 for a transmission adapter and you can have overdrive. Surely that will be a big difference. I figure the adaptor/AOD tranny will pay for itself in the long run with the current gas prices. I'm about to do the same to my bird. Good luck.
 
verdejor said:
hi, new to the forum. $850 for a transmission adapter and you can have overdrive. Surely that will be a big difference. I figure the adaptor/AOD tranny will pay for itself in the long run with the current gas prices. I'm about to do the same to my bird. Good luck.
Click to expand...

Can you provide a link to the company that is doing AOD's to our cruis-o-matics?

John
 
I don't know about "modifications" to the cruise-o-matics BUT I do know for certain that the C6 can be replaced with an AOD tranny by using an adapter plate. The kit comes with starter, flywheel, flywheel spacer, all bolts and the adapter plate. all you have to do is cut the "inner" ear off that is on the way for the starter gear to engage. PATC transmissions sell full modified C4's with overdrive also.

look up PATC transmissions for a C4 with overdrive.
If you want to swap a c6 for a AOD, here's the link : Ford FE Transmission Adapters

these guys sell full trannies also, pricey I think... FB Performance Racing Transmissions - Chevrolet, Chevy, Buick, Olds

lentech does also, but no prices posted...I guess they price whatever whenever...

good luck.
 
Fuel economy

Not knowing works best for me.

Headers made a big change for me in freed up power.

Also got Redline oil in Engine, Trans, and Diff.

I am planning on changing the intake and running fuel injection. I have also been thinking about putting a T-5 trans in it as well.

A side note I have been getting gas from Arco AM/PM & Flyers for years . Mostly because they are cheaper, but also cuz there more conveniently located to me. Now my newer car has 2 fuel consumption programs.
Consumption 1 I reset every fill-up.
Consumption 2 Is ongoing I reset it when I 1st got the car. It is my base line currently at 22.3 mpg.
So a few weeks ago I got gas at Chevron and I noticed when it was empty my consumption 1 was @ 23.6 mpg. So I filled back up at Chevron but I did not reset. At this point I think it dropped to 23.4 mpg still an improvement. So I went back to Arco am/pm this time I filled it with premium. (my car calls for mid grade) Can you believe it dropped to 19.8 mpg ! So I went back to Chevron And again 23._mpg back to Arco am/pm this time mid grade again 19._ So next time I am going to see what happens if I get premium @ Chevron
 
what type of fuel injection you're planning? my next FUTURE step is that. Was looking a the proflo kit since what I really wanted was the inglese system that I can't begin to afford lol.

I wan't something that won't really depend on a computer. (not too sophisticated... did I spell that right?...)
 
verdejor said:
what type of fuel injection you're planning? my next FUTURE step is that. Was looking a the proflo kit since what I really wanted was the inglese system that I can't begin to afford lol.

I wan't something that won't really depend on a computer. (not too sophisticated... did I spell that right?...)
Click to expand...

Let me know how it works out for you as I've also been thinking about converting the old 390 to a ProFlow EFI system.

John
 
I am planning to custom building my intake & muli-port fuel injection system.
I'd love to do a propane injection system. BIG $$$$ so I'll be running gas or alcohol . I also want to build a still so I can make my own fuel.
 
I am ignorant to the schematics for making a fuel still, but after reading a bit...I think I'd end up just drinking the beers and buy the efi if $$ is left over.

good luck. don't blow up...or else we may think it was another cell attempt to build a home-made bomb...underground!

take care.
 
A stock 390 with stock 4 bbl motorcraft no A/C gives maximum 11 MPG city and 19 MPG interstate. BUT, everything has to be right ( Timing, clean carb, carbon free valves and rings, right compression, oil pressure etc.)
That milage was using unleaded regular gas. Don't know milage with todays 10% ethanol garbage.
 
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I recently installed a pertronics ignitor, electronic ignition unit in my bird. Also the high voltage coil as well. I saw a 3 mpg increase off bat.
From 11 mpg to 14 mpg. Not bad for $120 in parts. It only too me an hour to put it all in and time it.
 

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