Wow, I feel blessed for I had a 93 f150 supercab with the 5.0(auto) HO and I got 15 city 19 highway. I now have a 98 expedition with the 4.6 and this 5800 lb brick gets 14 city and 17 highway of course in 2 wheel drive, too scared to know what the numbers are in 4x4.

 

Seafoam or Techron

 

The "sixlitre" tuneup as it's called was named after one of the guys in the Bronco forums. Basically you bump timing 2*, gap some motorcraft coppers plugs a little wider, and get a good rotor/cap wires and a super coil (MSD, mallory, etc). The basic principle is to throw a huge fat spark and then have the timing bumped so that the cylinder ignites 2* earlier in the rotation. This gives a more complete fuel burn (ie better mpgs) and a few more HP. Here's a list of what I'll use on my 5.8 when she gets back into a truck (I put the right links for your 5.0L instead of my 5.8L).

Coil $44.95 MSD Ignition 8227 - MSD Blaster TFI Coils - Overview - SummitRacing.com
Wires $41.95 Ford Racing M-12259-C301 - Ford Racing Spark Plug Wire Sets - Overview - SummitRacing.com
Plugs $15.60 Motorcraft SP450 - Motorcraft Copper Core Spark Plugs - Overview - SummitRacing.com
Cap/Rotor $28.95 MSD Ignition 8482 - MSD Distributor Cap and Rotor Kits - Overview - SummitRacing.com

So... $131.45+S&H to do the sixlitre tuneup. I have heard other guys use Accel parts instead and get it all for under $100 but I have had good success with MSD parts and don't want to change what already works good... You can also keep an eye out if you go junk-yarding; sometimes you get lucky and find some good stuff that the guys inside don't care about (ie you get to buy it dirt cheap). The link to the bronco forum (with specific instructions) sould be in the post that i gave you already.

As for cleaning the injectors. I buy a gallon of Lucas once every 2-4 years and usually put a tank full of treated gas through every 5000-20,000 miles depending on how hard i run the engine. Keep in mind gas is a ton cleaner than it used to be, and running cleaner once or twice a year is about the cleanest you probably get the injectors... That is without pulling them for a manual cleaning (a big pain )

 

Personally, I do not think the six liter tune up is necessary. I would just go with Motorcraft plugs and plug wires as well as cap and rotor and coil. I have had my truck both ways and there is no difference at all that I can tell with how it runs or with miles per gallon.

 

so basically all the parts and don't bump the timing?

 

I have the timing bumped on mine with all MC parts.

 

Just a quick thought but do any of you guys run synthetic fluids?? They claim you will see a little increase if you run synthetic in your entire driveline. Motor, transmission, & axel. Transfer case if 4x4 & front axel. Just cruious as I am thinking about it not only for the longer life of the fluid. I hate changing oil when it's cold out. LOL

 

Good info. Thank you very much for taking the time to answer questions. Based on my budget, I will do a tune-up and add some cleaner.

 

I use Berrymans B12 injector cleaner once a year. My truck gets about 14 city and a max of 20 on the highway @ 60 mph. 75 mph will drop it to 18.
Overall average is 17 depending on the stop and go on my commute.
x2 on the copper core motorcraft plugs and the sixlitre tune up. I did not notice an increase in mileage but the truck does run better and the old parts were not that old.
Synthetics can help and I will be using some in rear axle when I change it this spring.
Merry Christmas
rikard

 

Something else I noticed is that fuel economy has been slightly down since the ethanol has been blended with the fuel. I wish they would get rid of that.

 

When you guys advance the timing, do you have trouble starting when engine is warm? My 92 F150 4wd reg cab long box gets 13mpg, never had it do any better no matter how I drive. Most of my runs are under 20 miles and chasing on gravel most of the time. Never messed with the timing, does it make much difference? I never run ethanol, I grow corn, but personally I havent had much luck with the stuff.

 

You never run Ethanol? May I ask where you get your gas for its a standard that all pump gas in all states( not sure of California) have 10% ethanol and I heard that it may be going up to 15 here sometime.

 

Ethanol is one of my favorites, it does seem to net less mpgs in cars and trucks, and plays havoc on marine and small engines, especially 2 strokes.
Another favor from the good folks at the EPA and Fed Govmnt.

 

I have also heard form many people that they feel it has damaged their carburetor.

 

It made it necessary for me to rebuild the carbs on my outboard motor, and ruined a fishing trip........now I only run "clear fuel" in my 2 stroke outboards.......Thanks EPA.