Not questioning that you know your stuff sir. Just sharing my experience.
Let us know your results.

Thinking EFI on an earlier built car, which ofcourse is lacking EGR;
What would one think of, instead of normally optimizing ignition timing at cruise rpm, now retarding ignition timing instead. Letting the engine get a bit less eficient so more throttle is needed to maintain speed.
More throttle, less vacuum (with same speed).

Would this have a similar effect as an EGR?

Lockup equipped 727, 42/44/46/47/48 are not modulated lockup designs.
You will never get zero slippage as long as you have power coming from the engine and vehicle “resistance”.

When you get too much clutch slippage in lockup you will set a code. 60-100 rom is quite common.

If it takes too long to achieve lockup you’ll set a code too. Once the lockup solenoid is activated a timer starts and it must achieve a certain amount of lockup in a certain amount of time. If you don’t that’s when the code sets.

All part of OBD,

I'm just wondering with all the gear swaps, did everyone install the corrected speedometer pinion.

That's a lot of turd polishing there....no that's a lack of knowledge on your part...and showing it on the internet

The fsm is a poor substitute for proper bearing preload.
Trying to figure out how to make a 1970 automobile go 140 mph without vibration and stopping issues will lead one to figure out how to set up front bearing preload with the proper tool. It does indeed effect gas mileage and proper braking.

Rolling resistance and engine efficiency is the issue here and it does not matter what kind of car it is.

Monday Wall Street Journal has a front page article on getting better MPG from pickup trucks. Author of article seems to believe that simply putting a very small cubic inch engine in a pickup is the majority of the effort. Almost no discussion of gearing and transmissions.

Most authors of articles in the media have a degree in "useless studies" and know virtually nothing about what they write about. What qualifies them as "knowledgeable" is that they know slightly more than the other "journalists" they consort with.

I’d bet a 440 would get better mileage in a fully loaded c-body, than a slant 6 would, all other options being the same.

Absolutely. A small engine working itself to an early junkyard grave is not going to get better mileage than a larger engine that barely has the throttle open to do the same job.

Big engine or little engine, still takes the same hp to go a certain mph, all things equal on the vehicle.

Axle efficiencies come into play. The internals of the transmission [working through a fluid] driveshaft and axle gears [working through a fluid] have to spin at higher rates, consuming more energy.

Lower [numerically] gear sets offer increased efficiencies, this can be seen in the trucking industry by just researching "downspeeding". If you have the torque on-tap, slowing everything down offers a benefit in fuel economy.

By improvement, I am referring to single digit percentages, which may or may not be significant to you. In trucking, it's a big deal. If I turn a 13 or 15 liter engine 200 times less per minute while producing adequate torque, it doesn't take long to realize there is some energy conservation taking place.


For what it's worth, I do work for a Class 8 truck OEM and have spent some time on the subject.

but when the smaller engine makes 1/2 the power the larger engine does, it's going to be working harder at that same hp level.

No, they will be doing the same work, actually the bigger one would as it has to overcome friction from bigger parts or longer strokes or both.

Also the smaller engine has less distance within the chamber for the flame front to travel across. And since the smaller engine will be operating at a lower vacuume leval the air and fuel molecules will be closer together upon ignition and therefore will burn more completly. Goody could probably back this one up as that is the reason why they run engines with just barely enough power to pull the maximum load the maximum desired speed and then gear it to get the load moving.

With my new Holley Sniper EFI setup I can see exactly how much fuel I'm using as I drive down the road. Once you can see exactly how much fuel you are using you can figure out how to improve it.

I have a 5 speed manual transmission in my car and I can see a big difference in fuel use if I cruise down the freeway in 4th rather than 5th. That test is basically the same as changing the rear gear.

I learned a lot about engine performance under different pavement, grade, wind and speeds using this relatively inexpensive add-on trip computer:

http://www.autospeed.com/cms/article.html?&title=The-OzTrip-Car-Computer&A=0639

At the time I bought mine 62 USA pennies equalled a Austrailan Dollar.

After having the Oztrip for awhile I realized I could go beyond the instant MPG and use the trick of first reseting one of the three mileage memory counters,
then watching the Gallons digital readout until it changed by
exactly 1.00 gallons, or 2.00 gallons, etc

As AndyF says above, seeing how fuel consumption changes as you drive is very educational.
Climbing 4% grade hills at the same MPH in different transmission gears is eye opening.

+1
If a bigger engine got better or the same mpg tooling around we'd all have bigger engines in our late model cars...
Throttle open more = better air and less work to overcome pulling air through the tiny straw of cracked throttle blades.

Well there is an argument to be made here.

Generally, cars with smaller engines are lighter - compare a slant 6 to a 318 to a 440. So in this case the "lighter" car would get better milage.

The other piece of this equation is the time to reach a given speed. Generally the smaller, lighter cars will see better economy because they're slower to accelerate whereas the driver of the 440 car probably has a heavier foot - getting into all 4 barrels !!

So the only way to really gauge the economy would be to have all vehicles geared the same, weigh the same and accelerate and maintain the same speed over a given distance.

I strongly suspect the results would be very close.

My car uses 36 lbs/hour at 65 mph in fourth gear and 32 lbs/hour at 65 mph in 5th gear. So that is the difference due to gear ratio.

My rear end ratio is 3.54 and 5th gear is 1:1 while 4th gear is 1.23 so this test is equal to a 3.54 rearend vs. having a 4.30 rear end.

Anyone here on Moparts presently driving a Ford F150 with the 2.7 L twin turbo V6 ?

Does the Ford trip computer allow you to view the MPG at a steady level highway speed?

How many psi of boost is needed to drive in the 60 to 75 mph range on a level highway?

http://www.wardsauto.com/engines/2018-winner-ford-f-150-27l-ecoboost-twin-turbo-v-6