what fuel economy range should i expect from my 73 Swinger w/ A904?
Just bought it, and only got 170 miles out of a full tank. Exactly what size is the tank?

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Ron
73 Swinger
Bremerton

It should be 16 gallons. Was it 170 miles till the gauge read empty or 170 miles when you ran out of gas? The gauge may need attention, the sensor, or perhaps the regulator in the instrument cluster.

To check your fuel mileage, top it up again, then divide the number of miles driven by the number of gallons it took to fill it. Check it two or three times this way to allow for variations in fill level.

You should get somewhere around 18-21 mpg depending on where and how you drive, and, of course, the state of tune and condition of the engine.

CJ

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Part of Tyrde-Browne Racing

I agree with ceej,22-24 MPG should be easy,if not there's a problem

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V8?? We don't need no stink'n V8!!

It takes a lot of tuning to eek out those extra mpg's unless you're just one of the lucky ones who has a good combination that gets 20+ without even trying. Most people will average around 18 if they don't drive like grannies. After that you have to start adjusting the carb, timing, as well as play with electronic ignitions and exhaust to start getting past 22mpg.

Then again I'm talking about real world driving. I'm not the type who will do 55-60mph on a flat stretch of highway, fill up and calculate 25mpg and say that's what my car gets. Because that's not real world driving for me.

Mine has a super six, 2 1/4" exhaust, HEI ignition, NOS distributor and NOS carb. Engine also only has about 15,000k on it and I get 18.5 city and 22.5 city/highway hybrid (doing 60-75mph). I could get a little more by recurving the distributor and throwing a 4 speed OD in it. After that the only other option is a lighter A body or a Feather Duster/Dart Lite.

I drive a boxy 74 Swinger very aggressively, weighing in at 3600 lbs. Worst mileage on a stock 225 is 20 mpg, average is 22 mpg with a 2.76, 8 3/4 Sure-Grip running P235-60R 14's.
At 9.5 to 1 compression it is much better, figure 23.5 to 25 mpg or more on trips.
My car weighs 3380 lbs with a full tank, 3600 lbs with me in it. Book specs show up to 3180 lbs. in 1974.

A carb heat deflector helps allot along with, a electric fan, cold air intake, a working vapor canister and SL6Dan's fuel line mod. This helps during heat soak and saves the gas from vaporizing when the engine is hot and not running.
A recurved distributor also helps as long as you keep total timing below 52 degrees.
A good hot ignition with out the ballast resistor is also a plus.
The 2 1/4" exhaust up grade also helps mileage.

Click on the red link below my name to view pictures. Once they come up double click on one for full screen slide show mode.

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Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG