just curious how you guys running carbs work on getting better gas mileage out of them?

 

Switch to fuel injection

When all stock mileage was decent, but as power goes up mileage goes down. The best I managed out of my 305 HO w/cam,intake,exhaust was about 23mpg on a road trip. Now it's making much more power and I'm down to 13-14, but I drive it like I stole it whenever it leaves the garage.

 

Fuel mileage is a dirty word for me. If I was aiming for that i'd have bought a honda

However, to answer your question:
Make sure everything is working right, non-plugged air/fuel filters, good ignition etc.
Then setup carb right, correct jetting etc...
Then just drive it like an old lady...

oh yea, OD helps too, my 3.23 gears and no OD gets me at 3000RPM to keep up with traffic on the highway

 

I noticed a change in fuel economy every time I have done something to my engine. My carb is stull really futzed up, but when I was gonna rebuild it over spring break I drove into a pickup truck instead, so the carb gets to wait.

They say K&N air filters are supposed to improve economy. I never really understood how they could claim this, because their stock replacement filters would allow more air to the engine, which would in turn require more fuel...

Oh, and I never 'drive' anywhere, I haul ***.

 

I can tell ya that seeing gas streaking down your quarter panel from the leaking gas cap doesn't help! But the principle I am getting at is a valid and often overlooked one, make sure you don't have ANY leaks. And gas leaks can be hard to find since it evaporates so fast. I had one on my holley inlet that only leaked a drop gas every few seconds. But it made a big difference at the pump.

To directly answer the original question: TUNNING. You can get some great mileage with a carb if it is porperly sized and tuned. Comparing city mileage to what I see over on the TPI boards, carbs can hang with that. On the highway with highway mode enabled is a different story. But as others have said, the driver makes the largest impact on mileage.

 

yea my q-jet inlet is still leaking... not sure how or why but... It sure ends up giving me lousy gas mileage, and a nice gassy smell...

 

part of that is pumping losses. kinda like when you have a dirty air filter. when you have a dirty or restrictive filter it restricts air which makes the motor work that much harder to get the same amount of air in.


fyi a motor at WOT generally makes more power per unit of fuel then a car at only partial throttle for the same reason.

 

Yeah, but it's not just that. I will, say, hold second gear in traffic for a few seconds before I see an opening to pass, etc. I'm sure if I calmed down a little I would do much better. I was running between my girlfriend's house and my own tonight. It's about a 30 minute drive for a sane person, but because of the hurry I was in, I did each trip in like 15-20 minutes. And went through a LOT of fuel...