Alright everyone. My truck is up to 192k on stock engine and trans. She was pulled off the road last year and re did all the suspension. Well shes back on the road. I did a trip recently roughly 450 miles. 225 empty, 225 loaded with a 10 ft trailer and a motorcycle. And i am disapointed with how it performed and the mileage i got. Averaged altogether 9mpg. Terrible power pulling hills. Kiterally could not pull hills.

Leads me to mu thought, engine and trans swap. Anybody have any thoughts that do decent mileage and can pull a stupid friggin hill? Not picky about make and everything either. Id love to hit high teens n low 20s in mpg. Thoughts? Im pretty frustrated with her lately.

 

Not sure what engine and transmission you have.

A lot factors in with axle, 2wd or 4wd. What size tires?

My '92, 4wd, 300, Ext. cab gets 15mpg. That's with 3.08's, LT 235's and M5OD. Everything thing else I have is 302, 307, 351. My 307 gets 11's, 302 gets 13-15 and just rebuilt the 351 so I have no numbers yet.

All of my trucks have 4wd and are Ext. cab.
The 307 has 3.55, the 302 has 3.31, and the 351 has 3.55.

Edit: I should note that the 307 has an AOD, the 302 has a 4R70W, the 351 has an E4OD.

 

My apologies, the frustration lol.
It is 9250, 5.0, e4od, 3.55 gear, 33s. 2wd, No lift, decent alignment, rebuilt front suspension, and rear spring mounts n bushings, new tanks (both were leaking in the past), new plugs, year old wires, year old cap/rotor, new air filter, new fuel pressure regulator, new o2 sensor, and more. Cant remember more though. I just can not pull it out of single digits. I pulled it last year at 7mpg. I have increased it some, but not nearly enough.

 

??? Is that 1992 150, 250, 350, or something else? Size of the truck will make a difference, if you want help you are going to have to help us know what you have... we can guess all day and still not answer the question....

 

It's an F150, because the 302 was never put in anything bigger.

If you are dead set on an engine swap; put in a 351, then swap out the rear end for 4.10 gears. Your mileage will suffer because of this, but your towing capability will be much greater.

 

Sorry, my phone can be tricky. Its f150. Did not notice the typo. I cant do 410 rears, my mpg needs to go up. I have had some thoughts, but itd make every person on this forum pissed lok

 

I had a 1993 w/ 5.8 and it was gutless as well. Put a vortec supercharger on it which helped but still felt underpowered. Mileage was also dismal. Not alot of ways to make it better without spending major bucks. Personally, I'd look for a similar 3/4 ton with 460 and sell what you have. Money wise this is the cheapest option; you'll be ahead but fuel mileage will still suck (same as you are getting or slightly better but nowhere near 20mpg). Other options are get a newer truck (3.5 EB or diesel) if you want power and mileage.

The mileage I on my vehicles (shown in my signature below) was as follows FWIW (unloaded freeway@65mph/towing freeway @ 65mph with 5k traveltrailer)

Supercharged f150- 14/8
F350 V10- 12/7
F250 powerstroke- 20/13

 

I guess heres my argument (always been a ford guy) but a certain bow tie competitor, gets much better mileage and pulls a whole lot better. How can it be so different? Ive done so much on it to bring the mileage up and still dont touch close to what i actually need. Ive had thoughts of the lq4 because of the power. 345 hp stock. And people have been claiming great mileage. All i know is somethings gotta change.

 

Have your fuel economy figures been done allowing for those 33's?

I'd be sure the timing is correct (make sure the outer ring on the damper is not spun) the advance it until it pings then back it off a degree or so. Be sure the advance mechanism is working... check the cam lift to be sure you don't have a bad lobe or two. Replace the timing chain...at 192K I'm sure it's shot. The whole motor may need a rebuild...

Those Bowties always get better mileage until you buy one then find out they don't. Newer trucks get much better fuel economy than the older tech ones we discuss here... that may be your best route if that's in your budget.

 

Ive looked at whole rebuild, and ive also looked at a whole powerplant update. Would really like a whole rebuild update though. I know its always been good to me. Just my current numbers are about despicable.

 

If the chevy truck you are comparing it too is much newer then that is your answer as to why it has better gas mileage. Newer trucks are going to have better mpg since they are built in a time when mpg is a big concern for a lot of people, where as when our old trucks were built I don't think it was as big of a deal since gas prices were lower. Also a new chevy will be MUCH lighter then our trucks and that alone can make a difference. Plus they are able to build engines much more efficient these days then they used to.

But I personally have not seen a full size truck that actually averages over 20 mpg in the real world. I've heard a lot of claims of great mpg, but whenever I talk to someone that actually owns one of those trucks it's more like 17-18 mpg at the most.

EDIT: I looked into a newer truck at one point for better mpg. But for any decent newer truck I was looking at around $25-$30k. When I actually calculate it I average about $1,500 a year in gas and I have about $15k into my truck over the past 6 years. So it would take me about 10 years before I spent the $15,000 in gas with my 460, which to me is not worth buying a new truck.

 

It is in a newer truck (2003) but i think its more along the lines they are built to be mofe efficient. Does someone have some ideas of what could be done during a rebuild to help me out if i end with that route? I know there are really only a few cams to use, but dont remember off the top of my head which ones. If i do a rebuild, i will replace all injectors and vacuum lines. I no longer have cats due to michigans lovely winters. So i have also thouhht about removing the air pump and other junk that runs with it. What are some thoughts of sone things i could do? Keep in mind i am wanting to hopefully regain some mpg. And if i do the rebuild route i will also rebuild my e4od while everything is out. May be next year til im able to do everything since i no longer have a garage.

 

The Holy Grail for mileage / towing is a Cummins. The 4BT gives better mileage and good power, the 6BT gives better power and good mileage. But swaps are usually more expensive and take longer than most people expect.

If you want the best mileage in an older gas engine, you probably have the right one in the 302. Somethings wrong that it's getting as bad as it is. And 4.10 gears might not actually hurt your mileage that much (the 302 does need to spin a little).

If you need more power than that, my '95 F-150 SuperCab shortbox 4WD had a 351W, E4OD, 3.55 gears and 32" tires. It would get ~13 mpg in normal driving. Hauling a slide-in camper and towing a CJ5 (~ 10,000 lb GCWR) I'd still get 7~8 mpg at 65-70 mpg. It was no powerhouse, but I was always happy with the performance.

If you want a more complicated gas engine swap into a newer design, I probably would go with the heresy of an LS as well. I don't have any personal experience with them, but know a lot of people that like them. And personally I don't like the Ford mod motors.

 

I have toyed the idea of the cummins. But the cost...might as well write a blank check. I be happy to keep my 302 n e4od if i have a dream of getting back a little mileage. Even if its just mid teens, i can work with it.

 

No you don't understand, those 33" tires are killing both performance and fuel milage and you will do much better on both counts with 4.10 gears. If you did nothing else to the truck a gear change alone would be worth it.