I've beat this dead horse a million times but my car gets like 10mpg. I've done my research and similar setups have been getting up to like 15mpg city. Take in mind I don't think I fare well highway either, I think it still sits around 10mpg.

1406 Edlebrock + edlebrock intake manifold

260HP 350tq Crate 350

Everything else is pretty much stock.

I was curious why and if your setup is similar what kind of mpg are you getting?

I don't floor it either. The car does seem sluggish as-well, I assume it needs a transmission rebuild and headers to fix that.


"I am running a stock 350 with edelbrock performer rpm intake and 600cfm edelbrock 4 barrel and 4to1 hedman headers with cherry bombs and I get pretty far on 1 tank of gas. Also running a jegs hei distributor and th350 and I am getting close to 15mpg."

I mean whats up with that? Especially since that thing even has a th350.

 

If you want gas mileage get a civic. Even more when you are running a carb setup on a healthy motor.

Car seems sluggish? Is the carb setup correctly? What are your gears?

My friend with a L05/TPI top gets 13-15mpg. I used to get 16 with a L03 with a LT1 Cam/2400 Tc/2.73s with a 700r4 with a shift kit.

Make sure the car is running correctly before even speculating anything.

 

Actually thought about it but that's besides the point. I know it will never get great mpg derp, not an idiot bro.

Gears are stock and everything is pretty much good to go. Been working the bugs out all year, slowly but surely. Just surprised it isn't getting a few more miles per gallon.

 

carb, timing and possibly Cat? That is sad mileage but sluggish is the FOCUS! Why? Is there too much fuel going through not being used? Something is wrong. What size Carb? 600?

 

Gears are stock? You can have anything. Pull your cover and check the stamp on it. You can have 2.73s, 3.23s, 3.42s and even lower depending on if its been swapped. Gears can help if you are worried about gas mileage...

Not to be a dick but if you arent asking a very hard question seeing your setup. Fix your slugish problem before worrying about mpg.

 

the poor fuel mileage is probably related to the sluggish running.
what distributor do you have?
does it have mechanical advance and is it working and tuned?
does it have a vacuum advance and is it hooked up?
for best mileage and driveability, you need both properly working and tuned vacuum and mechanical advance.

what do you have the base timing set to?
somewhere between 8 - 14 is usually good.
what is the timing at idle with the vacuum advance plugged in?
varies with what the motor has in it, but 20 to 26 is usually good.
with the vacuum advance unplugged, what is the timing at 3000 RPM?
depending on the compression ratio, heads, cam, and quench, 28 to 36 is usually good.
with the vacuum advance plugged in, what is the timing at 3000 RPM?
again, depending on what the motor has along with gearing, somewhere around 42 to 50 usually good.

 

PITA to tune right and overall not a great carb. switch a holley and tune it.
the slugishness is probably from the carb running too rich and just dumping fuel, which would also cause the poor milage.
no carb is gonna be set up for YOUR engine out of the box. you have to take the time to tune it to what its sitting on top of.

 

You can take an Edelbrock carb out of the box and assume instantly it's going to need to be jetted down two jet sizes. (Not sure about the EPS) They are actually easy to tune imo. Get a wideband or borrow one and get you AF's straight. You just answered your own question in the first post! My car's sluggish and get's crap mileage doesn't take a web forum post to deduce. You probably might need new plugs from burning rich also. They jet these carbs out of the box pig rich.

 

I've got the same motor as you and get the same MPG with a Holley 650 carb. However, it runs pretty good, and I get around 18 on the hwy. 3.23 gears.

For the hwy make sure your torque converter is locking up or the MPG will suck.

 

WHS