best way to improve fuel economy

[brsslam]

Okay i want to try and improve the fuel economy on my truck. My truck is a 86 chevy k10 with a 350 and a th350 trans. it has a 4 inch lift and 31 inch tires, and what ever the stock gears are it also has a edelbrock 4bbl carb. I know i wont be able to get good mpg on it but i want to improve it as much as i can. Right now im getting 5-7 on a good day and 3 on a really bad day. i know i can get better than that, i just wanted to know what would be the best way.

would a new tranny help?
I have also seen kits where you can change it from a carb to tbi or even efi. are they worth it? do they help?

 

[rich weyand]

Carb to TBI will help, and no it isn't worth it, dollarwise.

Your Edelbrock is running rich as a cob. They're setup that way right out of the box so you don't lean-kill the engine if you don't bother to tune it, which most people don't. I have 350/TH350, 31" BFGs (not known for gas mileage), and a 3.73:1 rear end on a K10, and I get 10 in town and 12 on the highway.

You need to tune the carb. You can get an A/FR meter and tune it that way, or you can copy my tune.

A couple things. Move the vacuum advance to the manifold vacuum port on the Edelbrock (driver's side front) from the ported vacuum port (passenger side front). Then set your timing to 14-16* BTDC.

To lean out the carb, you can try this tune. I got this tune for basically the same setup using an A/FR meter. Jegs has all these parts.

Primaries: jets .092 (#1425), rods .062 x .052 (#1441); secondaries: stock; step-up springs: 8# (comes with #1464). You will also need to replace the airhorn gasket (qty 5 is #1499) when you change the primary jets. Adjust the float bowls while you are in there, as they will be wrong.

Here's the manual on the carb for setting the floats (which will be wrong right out of the box and can kill mileage) and tuning the idle screws:
http://www.edelbrock.com/automotive/misc/tech-center/dl/carb-owners-manual.pdf

 

[350runner]

junk the eddy and get a quadrajet that's the best easy way to gain mpg.. no offense rich.

Sent from the dust in front of you!

 

[rich weyand]

No, I agree, a new properly tuned Qjet will get a little better mileage than a properly tuned Edelbrock. My recommendation is to talk to Sean Murphy over at SMI carburetors. That'll set him back 400, and maybe perform best with a new intake manifold, depending on what he has on their now.

But, he should be able to get 10 city/12 highway with what he's got for about $40 in parts. And he won't do much better than that with the Qjet.

Most people diss the Edelbrock because they don't tune the damn things! Well, DUH!

 

[MadOgre]

I agree Ceasar but its hard to find a quality Quadjet these days. Even a lot of these so called high quality builds are still not addressing the fuel well plugs! The Edelbrock will do fine if he tunes it right. Once I tuned mine it was much better! MPG wise.

You can easily do 15 mpg.

I wouldn't go more than 10 degrees advance with the timing maybe 12 max!

Change all the fuel filters, Air filters, oil change, diff oil change and wheel bearings repack. Make sure you got good spark! Clean all the spark plugs and probably need new cap and rotor. Check to make sure all your belts are aligned properly and nothing is seizing like alternator or air conditioning compressor. Make sure your fan is not stuck on. if its a fan bolted directly to the pulley with no clutch then find a clutch or electric fan set up

 

[DoubleDingo]

Insert sarcasm font...the best way to improve gas mileage is to drive strictly downhill everywhere you go or have a tail wind...

No more sarcasm...you have some good suggestions above, that should help.

 

[firebane]

Insert sarcasm font...the best way to improve gas mileage is to drive strictly downhill everywhere you go or have a tail wind...

No more sarcasm...you have some good suggestions above, that should help.

We drive MASSIVE square blocks of steel. The aerodynamics of our trucks just simply don't exist.

I mean we could do this and help but then the manliness of our trucks is 100% gone:

You must be registered for see images attach

 

[DoubleDingo]

Somebody had way too much time on their hands to do that...lol...

 

[77 K20]

We drive MASSIVE square blocks of steel. The aerodynamics of our trucks just simply don't exist.

The best thing I found is that if I have the time to just drive slower. When I get off of work at 3am and drive down to my parents house 160 miles away if I do 55 mph instead of 70 that saves a lot of fuel.
And quite possibly my front end because there are a ton of deer out on the road at that time. Pushing air out of your way takes a lot of fuel.

 

[DoubleDingo]

The best thing I found is that if I have the time to just drive slower. When I get off of work at 3am and drive down to my parents house 160 miles away if I do 55 mph instead of 70 that saves a lot of fuel.
And quite possibly my front end because there are a ton of deer out on the road at that time. Pushing air out of your way takes a lot of fuel.

Driving slower definitely saves on fuel. A few years ago I visited an old friend down in Escondido, about 3.5 hours from here. On the way down I hauled ass, doing between 80 and 90 to keep up with traffic. I burned almost a whole tank (Subaru Outback) doing so and was completely frazzled. On the way home I did beween 65 and 70. It only added a half an hour to the drive and I burned just over a half tank. Not to mention I was much more relaxed after getting home.

A coworker from many years back had a formula that showed how much more fuel was burned with each mile-per-hour over 55 mph. It increases exponentially.

 

[350runner]

All the eddies I've had were dogs even when tuned. last one i had i sold even with the tuning kit and extra rods n jets i bought for it. found a nice looking q jet from the junk yard for 30 bucks and cleaned then rebuilt it $50 bucks later 17.5mpg was had over @70mph. best i could ever get with the Eddie was 14mpg if i drive like gram pa. the throttle response was spot on and made me smile and tires start warring out faster. lol

Sent from the dust in front of you!

 

[MadOgre]

Ya the Quadjet is awesome and superior to all others just hard to find a good one.

 

[cooter55]

Here's what I did. Got an adapter plate, harness and ECM from Howell engineering, a 2" throttle body from a wrecked '92 Suburban with a 454, a wide band O2 sensor and an electric fuel pump, and put fuel injection on my '73 454. Went from 8 to 10MPG and it starts, idles and runs way better. I have about $900 invested. If you are good at putting your own harness together, you can save a couple of hundred dollars.

 

[350runner]

pics of said setup. . this just got real interesting!

Sent from the dust in front of you!

 

[fussfeld]

Diesel.