where to start on trying to increase mpg 84 c10

[NCTyphoonKid]

Where to start on trying to improve the mpg on a stock 84 c10 with the 305. I'm planning on doing plugs, wires, cap and rotor this weekend. But what else can I do to try and help it out some.

 

[Old77]

Clean air filter, clean and properly tuned carb, fresh blinker fluid,....

 

[Georgeb]

Proper alignment, correct tire pressure and the hardest of them all..... Keeping your foot out of it LOL! Oh and grease those muffler bearings.

 

[NCTyphoonKid]

Maybe LS swap also??

 

[Old77]

That'll give you better mpg but will take a LONG time to actually come out ahead of the game, though lol just flush the windshield wiper grease and that will be good lol

 

[Keith Seymore]

Slow down.

The aerodynamic drag increases with the square of the speed (not linearly), so the effect is magnified at higher speeds.

Plus - it's free.

K

 

[skysurfer]

Keith and Cob are on the right track, you have to drive your truck a lot to get back any serious investment. I once did the math on an overdrive install and figured out that with the low miles I drive it would have taken something like 30 years just to break even.

 

[chengny]

One thing you do not want to do is remove your tailgate (or install one of those cargo nets - that's the worst thing you can do). Contrary to what may people believe, doing either of those will actually increase your fuel consumption. The reason:

If the tailgate is left up (and the truck is traveling at high speeds), the air flowing over the top of the cab is forced down into the bed. Because the tailgate is up, it has nowhere to flow out the back. This restriction causes a pressurized "bubble" of air to form over the bed - it's upper surface is at the rail height. This bubble prevents any additional air from flowing down into the bed. Consequently, the stream of air produced by the trucks forward motion can slip smoothly across the surface of the bubble in the bed - and then flow out over the tailgate rail.

With the tailgate removed - or just down - that bubble is never established. So when the air stream flows out the back it creates a huge area of turbulence (eddies). This turbulence has the effect of a vacuum - which increases the aerodynamic drag on the truck's rear surfaces.

The list of the effects of different setups goes like this - from worst to best:

1. Tailgate removed and a cargo net installed

2. Tailgate removed

3. Tailgate left up in place

4. Tonneau cover installed. This option actually yields an increase in fuel economy over just leaving the tailgate up. Ford ran some tests a few years ago and found that a tonneau cover installed on a F-150 reduced aerodynamic drag by about 8-10 percent. That doesn't translate to a 10% fuel savings but it does reduce consumption by about 2%

 

[Joe383]

As far as motor goes I would do things in this order due to cost of mods. #1 Ignition tune up and good air filter, #2 Intake manifold, #3 Exhaust system, #4 If you only have a 3 speed I would swap to an overdrive transmission.

Things like tire air pressure, type of tires, driving habits can make a difference too. Another mod if your willing to tackle is a TPI swap. A whole used TPI set up on ebay is usually pretty cheep around $350 or so. Only thing is you wont one from an aluminum head motor so the intake bolt holes line up proper. Another good mod that is fairly cheep is a vacuum gage. It will help you drive were your motor is most efficient.

 

[NCTyphoonKid]

I've heard about the tailgate deal the only reason I'm trying to improve the mileage is I feel like this 305 is just a tad bit thirsty seems to be worse than my 350 tbi in the 87. I think I'll start with a ignition tune up the distributor cap looks ancient along with the accel plug wires.

 

[350runner]

You need to get a turbulator...
https://youtu.be/5hMAaOdNkgI

Sent from the dust in front of you!

 

[Pender1]

One thing you do not want to do is remove your tailgate (or install one of those cargo nets - that's the worst thing you can do). Contrary to what may people believe, doing either of those will actually increase your fuel consumption. The reason:

If the tailgate is left up (and the truck is traveling at high speeds), the air flowing over the top of the cab is forced down into the bed. Because the tailgate is up, it has nowhere to flow out the back. This restriction causes a pressurized "bubble" of air to form over the bed - it's upper surface is at the rail height. This bubble prevents any additional air from flowing down into the bed. Consequently, the stream of air produced by the trucks forward motion can slip smoothly across the surface of the bubble in the bed - and then flow out over the tailgate rail.

With the tailgate removed - or just down - that bubble is never established. So when the air stream flows out the back it creates a huge area of turbulence (eddies). This turbulence has the effect of a vacuum - which increases the aerodynamic drag on the truck's rear surfaces.

The list of the effects of different setups goes like this - from worst to best:

1. Tailgate removed and a cargo net installed

2. Tailgate removed

3. Tailgate left up in place

4. Tonneau cover installed. This option actually yields an increase in fuel economy over just leaving the tailgate up. Ford ran some tests a few years ago and found that a tonneau cover installed on a F-150 reduced aerodynamic drag by about 8-10 percent. That doesn't translate to a 10% fuel savings but it does reduce consumption by about 2%

Well I'm riding around without a bed right now. That means I'm actually gaining gas, right?

 

[Keith Seymore]

Well I'm riding around without a bed right now.

Be careful if you have to stop fast (especially in the rain).

Also - take a look at your rear axle while you are accelerating and decelerating. You will become an instant expert on pinion nose windup and u joint working angles.

K

 

[Pender1]

Be careful if you have to stop fast (especially in the rain).

Also - take a look at your rear axle while you are accelerating and decelerating. You will become an instant expert on pinion nose windup and u joint working angles.

K

Yea, I've already had that issue a time or two. It's not a permanent thing, I've got a bed to go on it.

 

[Joe383]

Honestly though I would highly recommend a permanent vacuum gage. Try to drive were your getting the highest vacuum reading. Place it in a highly visible spot so your not taking your eyes too far from the road to look at it all the time like the A pillar or dash.