Question,

I have a 302, edelbrock 600, 4bbl and an edelbrock electric fuel pump...when i fill the 15gallon tank up, why is it that i burn so much fuel fast....1 full tank is empty within 1 week and i only drive it about 15 miles to work and return for a total of 30 a day....my mazda tribute has almost the same size tank and doesn't burn fuel like that....what could be my problem??? before you answer - 1) the carb has been adjusted, 2) gears are 3.25 in a 9" and 3) electric fuel pump installed to replace mechanical pump.....H E L P!!!!! Gas is killing me here!!!!!

 

so your getting about 10 miles to the gallon sounds about right to me

 

man are you serious????? that really sucks....to increase the gas mileage, lower the gear ratio??? - change out the intake from 4 - 2???? change the carb???? THAT SUCKS!!!! no take off power from the line!!!!!

 

You need to find where the problem is located.
1. Engine- Use a 2-3 gallon lawn mower gas can. Measure two- three gallons and hook a rubber line to input of your elect fuel pump. Drive to work /back. See fuel used.
2. Tank- I've seen some people put a fuel vent in these old trucks incorrectly and the line sucks fuel when driven only. Small fuel leak, maybe in the tank or fuel lines.
3. Thief- These tanks are easy to steal fuel with a hose. With the price of fuel someone may be taking a few gallons a week.
Good luck and have a great day,chuck

 

my little flatty only gets 8-10 mpg and thats better than i expected . the rear gearing in mine is a 3.92 and it is wound up good and tight real quick , thus burning the fossil fuel at a high rate . i've had 302's and they didnt fair much better in a truck , bout the same mileage wise . one big pointer already given , slow the hades down off the line . drive like yer grandpa !!!! i had a 90 sedan deville that when the kids or wife drove it got 12 - 14 in town and about 22 on the road . well when this grandpa got in it i drove nice and easy , i got 18-22 all the time in town and better than 30 on the road as i was in no damn hurry . keep the foot outta the gas !!

 

Was the electric fuel pump installed , because the mechanical pump was shot? Did you check the fuel pressure with a pressure gauge? Too high?? Carb should only need 4-7 PsI, that pump probably makes more.
Put a 2 bbl on it..
Keep your foot out of the gas!!..I know it's fun, but your payin for it
What size tire's?
Last resort...Get a 30 gallon tank..Heehee

 

Is this a math test? You are getting 10 mpg in a hot rod, probably with an engine running cold. I don't get it. If you want economy, why are you driving an Effie as a daily? Get a Yugo.

Of course, you'll lose the cool factor....

 

good point cmoritz ! i didnt even think about the pressure and / or wether it's pushing more than needed . mine {53} has an electric pump also and the ol' holley's on these flatties only wants in my case , about 2.5 psi or im filling the oil pan with gas and pumping it out the tailpipes , resulting in much wasted fuel . i would only go three or four days of mild city driving and she'd be dry , and i think the figures were roughly half of what i get now .

 

Gentlemen,

This is why I joined the website.....Awesome feedback...only 1 problem though...Why buy an old truck (hot rod it) if you can't beat those RICE burners out there!!!!! NO, I will really use the advice given...the PSI on my was 6-7, no thief on my tank (fuel cap locked), keep my foot on the pedal too hard (i think)...55 f350 has a good idea, maybe the carb is getting too much fuel...might get a regulator and tone it down..edelbrock recommended 6-7 PSI for the 302 though.....if i go lower than 6, will that make a difference in performance????? Remember gents, new to the fuel supply world and learning a lot through trial and error here!!!!

 

If you want to save fuel--Get a vacuum gage or motorminder and learn to drive
with the highest vacuum reading possible. If you are a RED-LITE bandit you can never get good fuel mileage. Remember low vacuum---low mileage high vacuum--- higher mileage

Have A Good Day -------Hotwrench

 

Do NOT put a 2bbl on it! A properly tuned 4 bbl will give better mileage than a 2bbl will. You will have 2 large barrels open when normal driving while the 4bbl will have 2 smaller barrels open while driving. The 4 bbl won't enter into it until the secondaries open. Keep your foot out of the seciondaries and it will improve.

Does it sound really good when you step on it? THAT's YOUR PROBLEM, THEN!

Seriously, 10MPG isn't out of line with a carb v8. Why do you thing fuel injection and smaller motors are so common?

SPark

 

i wont say i'm to old to get in a street race just getting smarter about it and my ol flattie aint gonna beat anything in a race no matter what , unless it's down hill in a vacuum where it's weight will play a role . i also just get a large charge outta driving mine { daily driver } and being different . im not out to beat the world , just out to have fun hot rod or no anymore . race 'em on the strip anyway it's safer nowadays and the kids need an example . look at the recent articles like where there were eight people { bystanders } at a street race in maryland or ri somewhere in that vicinity , killed during a street race , we had 4 out of 6 kids in an extended cab gm killed due to the driver racing on back roads here around middletown , all sorts of crap like that . i'm no angel as i did a lot of street racing in my youth , but to use a tired , but true cliche things were a whole lot different then . less traffic , congestion , and i hate to say this but we seemed to show a little more sense than most of the kids today .... ok i'm off the soap box now so good luck with yer quest but i think without a driving style change yer right in the ball park .

 

You think gas is a problem there? drive over the border into New Mexico...

Gas is 20 cents higher a gallon on average in New Mexico than in Texas

As you are finding out, most things with these old trucks is a compromise. If you want the cool factor and the ability to smoke the ricers then you are going to have to take a bit of a hit on mileage. Hotwrench gave some good advice, get a vacuum gauge and start monitoring how you drive....you'll be amazed.

It sure does feel good when you bury your foot into the floor though huh? LOL
Bobby

 

We had a thread on this topic maybe 18 months ago, maybe longer. There were plenty of people getting 15 - 16 mpg with 302's in effies or Bonus Builts and reasonable gears. There are too many variables to guarantee you can get that too, but I think something is wrong if you are only getting 10.

 

Is the 15 miles a straight shot or stop and go with a lot of traffic lights? That can make a big difference. The only thing I could suggest is a smaller carburetor. About 450 cfm is all you really need for that engine. However, it might not be worth buying one at this point if your Edelbrock 600 is new. At last check I'm only getting 11-12 MPG (combination city and highway driving) in my 48 with 350/350 and Holley 600 even with a 2:26 rear gear and I'm very easy on the gas. The price of gas is "killing" everybody but it's the cost of doing business if you participate in this hobby...