Questin about mileage

[Positively Ralf]

What's the highest mileage someone can get without making these engines full out performance engines? Something like a mild street build for example.

also, since this forum is about performance, what do mileage numbers average to?

 

[rbohm]

8) i assume you are talking about fuel economy, my falcons both got about 19 all the time, but they were basically stock engines, one with a 2100 autolite carb installed with an adapter. with the right selection of parts, and judicious driving, you can top 30mpg. however the average is going to be around 23 or so.

 

[Positively Ralf]

Yep yep! I was referring to fuel economy.

But to even get close to 30MPG, I'd imagine you would have to top it off at 80 in the highway right? anything higher could decrease MPG. That's just a guess though on my part.

 

[66200i6]

There are alot of things you can do to increase mileage. One of them is to never go over 60. The increase in fuel used and horsepower needed to travel over 60 goes up exponentially.

Have fun, Ric.

 

[early ford fan]

i realize this is a performance site,but it would be nice if someone knowledgeable about these engines could write a 'how to'for maximum mpgs.which cam,carb,head,if headers are a waste of money,what rpm to shoot for at 60[or 72],170,200,250,carb jet sizes and timing recomendations would be a plus.i replaced my 170 with a rebuilt 170 with a 250 head,i get poor mileage and suspect a 302 swap may give my more mileage.....

 

[Positively Ralf]

i realize this is a performance site,but it would be nice if someone knowledgeable about these engines could write a 'how to'for maximum mpgs.which cam,carb,head,if headers are a waste of money,what rpm to shoot for at 60[or 72],170,200,250,carb jet sizes and timing recomendations would be a plus.i replaced my 170 with a rebuilt 170 with a 250 head,i get poor mileage and suspect a 302 swap may give my more mileage.....

Agree. I to understand it's a performance site but it would be nice to see a separate tech article regarding the best products to use for mileage. Although I plan to stick with my 6 cause 8s can't get as much mileage as these engines can.

 

[Frankenstang]

i realize this is a performance site,but it would be nice if someone knowledgeable about these engines could write a 'how to'for maximum mpgs.

Hey guys, I'd would do some more searching on all different combinations of terms such as 'best mileage', 'best mpg', 'fuel mileage', 'good', 'better', 'improve', etc, etc. You'll find there are quite of few folks up here with an eye on efficiency...in fact most everyone when it comes down to it...heck even the max out turbo rides want to translate hp/torque to the ground as efficiently as possible, but there really is no one size fits all for any particular setup. Mainly because there are almost endless combinations here from stockers to fully/wildly modded. That's actually the great thing about this forum.

There are always the standard tips for driving: tire inflation, least weight possible, less idle time, 'egg under the foot' driving, properly tuned & maintained setup (ie ignition, fuel, oil, cooling), among others, but unfortunately it all depends on what setup you have now. For example I saw early ford fan's thread on his '81's mileage, and the first thing that comes to mind is how the 200's became less efficient over time as ford focused more on emission restrictions (smaller combustion chambers, lower cfm carbs, cannibalistic smog devices, etc)...but there are still good points like a better head design and a block pattern opening up more sbf drivetrain options like aod. There are plenty of mods to improve performance and efficiency but all will depend on budget & goals, and some might even depend on your individual state's regs.

All that being said, this is the best all inclusive guide to help you out with possible options, information about what you're starting out with, and understanding what factors/changes effect performance & efficiency of the ford sixes over the years, and improvements you can make on them:
The Ford Falcon Performance Handbook

 

[CZLN6]

Howdy All:

Thanks for the kind words Robert. Here's a summary I wrote down for a fellow Ford Sixer a few years ago. Since little has changed relating to mileage (except the price per gallon) I thought I'd share it.

"Ironically, most of the same mods that make power make efficiency/mileage too. The set-up and details are different though. Ak Miller’s used some of these ideas in a Mobil Mileage test back in the sixties along with some others like rock hard tires and extreme driving techniques to get well into the 30 mpg range.

Head: Higher compression, up to 9.3:1 (Real, not advertised}, stock valves and springs, and ports, three angle valve job and back-cut on intake valves. We recommend a port divider to improve cylinder balance. Mileage efficiency is a situation where a mid 60s 170 head with “Kidney” shaped chambers may have some merit. Smaller ports=higher velocity, smaller valves=higher velocity and vacuum, Smaller combustion chamber= higher compression, higher quench area to bore ratio for better turbulence and combustion efficiency.
Cam: Stock, or a specific mileage grind that maintains high vacuum and a low rpm power and torque peak. Caution- high CR and stock cam timing makes for high cylinder pressure and head. Make sure it is managed.
Exhaust: Stock, with a turbo type muffler. Although backpressure is not good for economy, neither is too much scavenging. The stock exhaust manifold helps to keep heat in the head and warm the carb base. And this will be a low rpm engine.
Ignition: DUI, DuraSpark, DuraSpark II or Petronix upgrade in a distributor with vacuum and centrifugal advance (68 and later). Set initial advance just shy of "knock". Note- The carb vacuum signal must be a correct match to your distributor. SCV to LoM, Ported signal to ’68 and later distributor.
Intake: 1st choice (with a DuraSpark II) for economy-two stage Holley/Weber, tuned to your situation.
2nd choice, With Load-a-Matic points type distributor- Use the smallest SCV one barrel that can meet the load requirements. Use some form of heat to the base of the carb, either hot water or hot air. Heated air to the carb helps with fuel atomization for more efficient mix with air and combustion.
******Under any circumstances tune the carb as lean as possible, but balance with ignition, compression and load. *Minimize choke and accelerator pump function.

More irony; All of these mods and parts would buy a lot of gas. Start with what you've got; optimize the initial advance setting on your distributor, make sure your carb is as lean as possible, not over-choked, low float level and there are no leaks, either gas or vacuum. High temperature makes for more efficient combustion and mileage. Do everything you can to keep the heat in the engine. Try a higher rated thermostat. Heat must be safely managed.

Make sure; your vehicle is as light as possible, tire pressure is at the maximum recommended PSI, there is no brake drag and alignment is dead on. A taller rear tire will give you a better economy ratio, but you won’t notice in MPG because your odometer won't show the change. Next oil change, try a lighter grade of oil. Synthetic oils make more mileage, but are twice the price. Do not overfill your gas tank and don’t be tempted to top it off. These two practices lead to spills from expansion and evaporation.

Some last thoughts; install a vacuum gauge and relearn to drive by using the gauge to maintain the highest vacuum under all circumstances, never exceed 55 mph, avoid cold starts, preheat before starting when possible. Don’t idle to warm up, just drive slow and low for the first seven miles. Don’t sit and idle EVER!!! Avoid traffic and stop-and-go driving. Slow down and coast whenever possible but be safe!. Keep accurate, repeatable measurements for comparison and records."

Hopes this is helpful.

Adios, David

 

[rbohm]

8) david makes a lot of good points, and he is right that a lot of the mods would buy a lot of gasoline. the internal mods are best done when engine rebuild time comes around. that way the cost of the better parts combination can be properly justified. as with any build, pick your parts carefully, and match them all to what you want from the engine, and what rpm range you are going to run in 80% of the time. as long as you dont try to build a ton of power, fuel economy will be improved due to increases in efficiency, and the fact that you wont be pushing as hard on the throttle to get to the same speed, which means you wont be using as much fuel to go the same speed.

 

[early ford fan]

thanks!i have both a vacumn guage and an 'auto meter'air/fuel ratio guage.i mounted the oxygen sensor in the hole where the air tube was with an adapter in the center hole.i have a 78 duraspark 11 distributer.i purchased a rebuilt holley weber and adapter from stovebolt.iwas getting around twelve miles per gallon with this setup.the a/f guage either stayed buried in the red or bounced all over.i talked about getting the proper jets for my setup from a dealer mentioned on the forum.he said he could get them for me but a weber would get better mileage.he said his sales people would contact me.[they never did]i have about 24 pounds of vacumn at idle.i took off the holley weber and installed a rebuilt yp from a 75 250 mav engine i bought.it also stays in the red.ive looked more and more into the megasquirt,but i haven't heard any great mileage claims there either.btw i set the timing and idle mixture according to this site.it has good power but hesitation.i guess i need to rejet the h/w or jump into fi.id like to direct mount the h/w.i also have a 108 two barrel that is rusty but may could be rebuilt.2100?

 

[Positively Ralf]

Thanks for the replies. My plans for the motor as a mild build that I'm sure would give me some more mileage goes like this.

1. Full tune up
2. Vaporizer 1bbl Carb
3. Going to try some of those new header products from CI
4. Of course electronic ignition

I was considering a cam swap but I don't know how cams work so I'll stick with the stock one. I'd figure a set up like that would give me a bit more power while at the same time maintaining mileage in the mid 20s.

Cheers!

 

[66200i6]

If you're not planning on changing the cam and increasing the rpm's you run you don't really need to install a header. You could go to the later exhaust manifold for additional flow if you think you need it. This would also help keep the exhaust gas's hot and maintain velocity.

Good luck, Ric.

 

[rickwrench]

I still get 30+mpg on the highway (@64mph) when the car is empty or lightly loaded.
23-24 around town.
We averaged just a bit under 25mpg on our last road trip, 5500 miles, hauling about 500lbs of equipment and with two kayaks strapped to the roof, at an average of about 4000ft altitude (sometimes a -lot- higher). And we were rolling around 70mph for a lot of the way as well.

As it is now:
Bone stock 65 200 block with at least 120k miles on it.
Early 80's 1946 carb (from a Fairmont, iirc).
Duraspark.
plugs gapped at .040"
3.0/1 rear end
T5 transmission w3.76/1 1st gear, .72 OD (S10 T5)
185/80-13 tires -always- at 38 psi (this size will change, as this tire size is now unobtainium).
Very over-sized radiator.

The T5 made the most dramatic improvement of any change I made. Next was the 1946 carb, Duraspark, and then skinny aired up tires.
The cheapest improvement (free) was to run the tires @38psi and drive at 64mph.
Stay below 65mph on the highway. For me, in the wagon, mpg drops about 1mpg for every 2mph over 65.

Falcons were designed to be economy cars. Add a five speed, duraspark, a good carb, and they get better mileage that most modern cars for a fraction of the cost.

Concerning "MPG":
My cousin was urging me to by a Prius (gag, never happen) based on the advertised mileage. But "miles per gallon" numbers are deceiving.
To get a true sense of the economy of a car, you need to look at total gasoline consumed to drive a certain distance. I.e. gallons per 100, 1000, 10,000 miles.
I like to use 10,000 miles, as this is about a years worth of driving for most.

At 30mpg my Falcon uses 333 gallons to drive 10,000 miles.
The ugly Prius get about 45mpg in the real world (despite the advertised 50+mpg) and uses 222 gallons to drive 10,000 miles.
So, I'd only save 111 gallons in a Prius, about $360 (@ $3.25gal) for the entire year. Hardly enough to justify even being seen in a smugmobile.
Falcon --> Prius: Number of years to recoup Prius purchase price ($30k): 83 years, 4 months (not including financing).

Going the other way, my old F150 was -lucky- to get about 15mpg, or 667 gallons per 10,000 miles. I save $1082 per year in gas driving the Falcon.
F150 --> Falcon: Number of years to recoup Falcon purchase price ($1050): 1 year (no financing costs).
Yeah, I left out the mileage improvement costs (about $2500).

Going from a 15mpg car to a 30mpg car (a 15mpg improvement) saves you 333 gallons per year, but going from a 30mpg car to a 45mpg car (also a 15mpg improvement) only saves you 111 gallons. Going another 15mpg, for fun, 45mpg --> 60mpg (Tata's Nano) saves only 55 gallons per year. And, you're probably safer on a motorcycle at this point.
The mileage mountain gets steeper the higher you climb, diminishing returns.

Rick(wrench)

 

[rbohm]

8) and ricks numbers dont include a lot of stuff like;

the cost difference between the cars
the cost of maintenance
the cost of insurance
etc.

when the falcon or the truck breaks, they can be repaired by the owner for cheap, where as the dealer is going to charge at least $500 per visit, perhaps more, with the prius. also the falcon and truck are likely paid off(if not you need to modify your loans :rolflmao: :rolflmao: ) where as with the prius you have a big car payment each month. and you can bet your insurance company is going like you having the prius over the cheaper to insure falcon and truck.

 

[early ford fan]

does anyone know if the holley 1946 uses the same jets as the four barrel?i would like to use a carb thats easy to get jets for since i have a air fuel guage.also anyone know what the last year that the 1946 wasn't computer controled?

 

[CZLN6]

Howdy EFF:

I do not think the 1946 used Holley jets, but I'm not certain. Very little of the idle, transition, and accelerator circuit will be effected by the main jet. The Idle circuit and the accelerator circuit are limited by built in channel restrictions. The mid range uses a sort of needle valve.

I do not think that the Holley #1946 was ever computer controlled. It was manipulated by a series of vacuum, thermal and electrical switches, supported by a factory preset (not adjustible carb and a cat convertor). It was less so in the 1980 model year, and more so until the end of carbed engines from FoMoCo. To get full access to carb tuning you will need to get intimate with something like the Holley 5200 or the like, with jetting controlling each circuit and interchangeable air bleeds.

The reasons the 1946 equiped cars were such good mpg cars was due to a very lean carb, in a high geared vehicle. It was not any big secret.

Sorry to be the bearer of bad tidings.

Adios, David