Gear ratio for 700r4???

[crazy4offroad]

What kind of carb?

 

[oneluckypops]

3.08's and a 700r4? i would not expect good mileage with that setup, try 3.73's.
higher ratio is not always the key to mileage.

 

[K10 DELUXE]

The carb is an edelbrock 600 performer series and i think it has a bigger jet kit than it came from the factory with but I have no idea what to re-jet it. The axles I'm swapping in when I do my lift and the 38's have 4.10 gears.

 

[HotRodPC]

OK, that's your problem. In 1 mile your truck is not warmed up. I'd say 5mph is right. And you're spending as much time idling as you are driving.

 

[philjafo]

Your only getting 5 mpg because of the way you drive it. I once had a jeep grand cherokee that had a mpg readout in the overhead console, during acceleration mpg drops to 1 or 2 mpg, at cruising it goes up to 17-18 during deceleration it shoots up to 40-50 mpg. The whole thing averaged out to 15-16mpg if I was nice to it. My point is your driving 1 mile at a time, your whole drive is acceleration and no cruising you wouldn't get good mileage from a 3 cylinder metro driving like that. Plus your either not getting up to operating temperature or your burning a lot of fuel idling. In other words the rich is coming from the choke not fully opening. Try filling the tank and drive about 100 miles then check the mileage on that trip. As for only 1 mile to work I'd walk, what your doing is bad for the engine and transmission.

 

[HotRodPC]

3.08's and a 700r4? i would not expect good mileage with that setup, try 3.73's.
higher ratio is not always the key to mileage.

The carb is an edelbrock 600 performer series and i think it has a bigger jet kit than it came from the factory with but I have no idea what to re-jet it. The axles I'm swapping in when I do my lift and the 38's have 4.10 gears.

And this is also confirmed with driving 1 mile to work. You'd do much better on mpg running 5.38's if all you do is drive 1 mile at a time.

 

[K10 DELUXE]

Well my grandpa taught me you never turn the key and take off...even in the summer lol so I let all of me vehicles run for a few before I drive them, although im sure it doesnt get up to temp in that amount of time. And the short trips make sense hurting the mileage. I'd be interested in changing carbs or working on the one I have. And by the way the axles under my truck are for sale!

 

[crazy4offroad]

Make sure you have a good paper fuel filter on that carb and not one of those cleanable screen bastards, they let a lot of trash through and the Edelbrock's idle circuit does not like it. Does it smoke black at idle or WOT? It is possible the idle air screws need tuned, and it is also possible the idle circuits are already clogged. The carb will try to make up for it by bleeding gas through the primaries and make a rich condition. If you think the idle circuits are plugged they are easy to clean. Take the top off the carb and hit the primaries (front jets) with compressed air. Re-assemble but DONT FORGET A GOOD FUEL FILTER!

 

[K10 DELUXE]

Yes if it idles for a few minutes and then I romp it there is BLACK smoke from the pipes.