I get about 5-10 mpg in our F250 with the 460 4bbl but since we drive it so little, it doesn't matter. As bigbackbeast says, it's difficult to get around the laws of physics with these heavy vehicles and large inefficient engines. You can buy a 660cc, 5 spd 4 wheel drive Suzuki flatbed (right hand drive from Japan) for about $8000 or less up here in Vancouver and it will get almost 40 mpg...

Years ago (mid 60s?) there was a kit to add an electric motor to the pinion shaft flange of Dana axles. If I remember, it was designed to give better acceleration but these days could be set up for improved fuel economy, traffic jam crawling and regenerative braking... Wonder if you could get 20+ mpg with such a set up in my Camper Special?

 

I have a 1992 f250 HD with 3.55'sand when i took the service box out of the back i got 10-11 on average. I wanted to do some certain mods since day one with an access tonneau cover to hid stuff in your box. When i did that i was getting 12-12.5. Then i did my exhaust from the 3" flange back, all i did was the flangs to a 3" thrush glasspack that has a 18" shell and is 29" in length overall that split to dual 2.5" and put a 30" pipe that pointed down at the end and called it quits. I have a noticable amount of power now but my stock exhaust was shot.
I am currently averaging 14.5. That total is based on about 150-200 kilometres in the city and 400-450 on the highway. I once drove and got about 15.5 mpg on almost all highway at 120-140 Km's and about 50 kms in a town. I have tried premium and got 14mpg when i towed a trailer with about 3000 pounds of arcade games and a machine in my box for about 200 km's with my tonneau cover rolled up.
I believe that it is very possible, just gotta look at the right upgrades.
I am considering on getting a throttle body spacer to see if that will help me out. I have also ordered a MindBlower Performance Stage 6 Fuel Maximizer off of ebay but it only works on fuel injected. It claims on the video that all the tests vehicles got a garunteed from 5-15 mpg's. You may get more or a little less. It is also supposed to improve power and all that stuff. Once i get it and install it, I will let you know what i will be getting. I want to be able to say "my 460 gets over 20 mpg".

 

Yes, maxell3655, I'll bet that it is possible to get over 20 mpg with your 460 if you upgrade to multi-port fuel injection and do a good number of other improvements, but this will get expensive... It should be possible to arrange that 2, 3, 4 or even 5 cylinders get no fuel out of their injectors once you are at cruising speed on the highway but were 460s ever made with such an adjustable/suitable injector system?

 

Maxell3655, please let us know how that mindblower setup works. I am interested. Going to research it right now.

 

I think it maximizes the sellers bank account. If it worked every car manufacturer would buy out the entire company. Auto companies strive to increase mpg every way they can and if if a $22 item would increase mpg by 5-15mpg every new car would have one. If they really worked and could increase your mpg for $22 by 5-15mpg everybody you know would have one too.

 

The car companies can't have all vehicles get better mileage because i believe that the oil industry wont let them. If all fuel injected motors had an upgrade like this if it worked cause i haven't recieved it yet so i cant confirm it. But the oil companies will slowly lose money because all of these motors wouldn't get much lower then 18mpg.

 

That is not even close to reality LOL. If the car companies could do it they would. Believe me if every car got 100mpg the oil companies would still make a huge profit they would just raise the price of fuel to compensate. You ever wonder why there is never any independant tests on these things that show an increase? the only tests you will find are the ones by the people selling them.

 

I do believe that that is what maxell3655 is going to do. When max gets the unit it will be installed in his truck. After max will (hopefully) post his results and experience with the unit for the rest of us to read.

And, voilà, an independent test of the product.

 

There was once a guy who made a carb that got something like 40mpg. Can't remember if it was 2 or 4 barrel but anyways it was back easily 20 years ago and this guy proved that it did that. As soon as the government and everyone else knew of it. They chucked that carb and destroyed the plans for it. Imagine if all they car companies started using that carb or make a similar one and come out with the same results then would we have this so called "global Warming" crap. I dont think so. I have heard of cop cars from the government with ford big blocks getting 35mpg. My grandfather knows someone who has an ex crown vic with a 460 with that mileage. If that was possible with those cop cars then why isn't possible with the rest of these vehicles. Why would a toyota tundra with the 5.7L get 8-12 MPG when you can buy a truck or car with a big block and do better? JADMT if that isn't close to reality, then what is?

 

I just accept the fact that my 460 from the 70's is just isn't going to do better than 10-12 MPG. It's paid for and is relativly cheap to maintain compaired to buying a new car that get 30MPG and paying $400 a month car payments.

 

My cousin lives in Versailles, MO and of last week he payed $1.49 for 87 Octane. I am moving to Fortuna which is close by.

Moreover, shop the Mennonite Stores as everything is CHEAP! Currently, I live in the California Mojave Hi-Desert and paid $2.41 for 87 last week.

 

I think those stories have been disproved by mythbusters LOL. Anyway I won't rain on your parades anymore, hope you get 30mpg.

 

I am pretty sure ill hit the 20mpg, 30 might be a strecth unless i get lucky. I got my stories drom a very reliable old fart who is in his 70's. He has been around the block a couple times in his age.

 

I wish you success in your quest for 20 MPG. When we get there we will have to start the 460 20MPG club

Did they have the speed density or the maf up there in Canada for our 460 trucks?

 

Does a 429 in a Bronco qualify for the club? If I go lite on the pedal and keep it under 70 I can get 21 on the freeway. Once I get in town it drops big time but I didn't buy it for mileage I bought it for fun.