I have a '77 Dodge Custom 4x4 with a 318 V-8 automatic transmission with 3 gears. I THINK it currently has a 4 barrel carb, but I'd like to take it down to a 2 barrel carb to save a bit of gas mileage AND to reduce the horsepower a bit so that it doesn't spin tires so bad in the cold weather here. I don't know what the current mileage is, but I'd guess it's around 15 mpg. What I want to know is a rough estimate of what the improvement on gas mileage would be... just a good guess is fine.
2007-01-17 06:02:50 · 6 answers · asked by promethius9594 6 in Cars & Transportation ➔ Maintenance & Repairs
You won't see much increase in mileage if your current carburetor is in good working condition.
When driving a vehicle with a 4 barrel carburetor, you are mostly driving with 2 primary barrels. These are almost always smaller than the barrels in a 2 barrel carburetor. Then more power is needed, like in an on-ramp, passing a car, towing, etc, the secondary barrels open as necessary to give the engine more fuel and air. The secondaries don't even open all the way unless you are under a very heave load such as hard acceleration or towing a heave load.
If you drive using a little restraint and use the 4 barrel only when needed, you will get better fuel economy with the 4 barrel than the 2 barrel.
The only thing I would consider replacing a 4 barrel with would be a throttle body fuel injection unit. But this may be a little costly for a 30 year old vehicle.
2007-01-17 06:14:11 · answer #1 · answered by Mad Jack 7 · 0⤊ 0⤋
If you keep your foot out of it, you'll be fine. As the previous posted said, a 4bbl only uses the front two barrels for normal driving. At approx 1/2-3/4 throttle, the back barrels start to open. 15 mpg in an older 4x4 is doing pretty well regardless.
2007-01-17 11:06:03 · answer #2 · answered by electron670 3 · 0⤊ 0⤋
This is a hard question to guess on. With any carb. if adjusted correctly, you will get the performance (or lack of) that you desire. An other way of reducing power is to put a restrictor plate under the carb. Any way you do it, it will require some tuning.
2007-01-17 06:13:04 · answer #3 · answered by Anonymous · 0⤊ 0⤋
Tornados are snake oil and have been proven over and over again to be useless. Keep the 4-bbl and re-jet it. Take it to a carb shop and have them do it.
2007-01-17 07:46:40 · answer #4 · answered by jdm 6 · 0⤊ 0⤋
originally that engine came with two barrel carb..
if I wre in Your place I will leave it with 4 barrels.
2007-01-17 06:10:13 · answer #5 · answered by Anonymous · 0⤊ 0⤋
buy a tornado for the air cleaner they work great.
2007-01-17 06:21:32 · answer #6 · answered by Anonymous · 0⤊ 0⤋