When I first bought my '83 F250 4x4, my gas mileage was hovering in the 6-7mpg range, with one foray to 8mpg. Then, I followed a kooky suggestion from a guy over at www.bobistheoilguy.com (BITOG) and ran a couple of tanks with heavy doses of Marvel Mystery Oil and ATF, believe it or not. After that, my mileage went solidly into the 8's, never again dipping below 8, but also never getting past 8.7mpg.

Then, about 1100 miles ago I added some Auto-Rx (www.auto-rx.com) to my oil because it is supposed to completely clean the internal lubricated parts of the engine, and also because Auto-Rx (ARX) is known to cure seal leaks, and my rear main seal was leaking badly. (The truck sat for a long time before I bought it.) One of the things that a lot of the guys over at BITOG have found out about ARX is that it pretty reliably cleans piston rings, freeing them up so they seal better.

I've also been putting this stuff in the gas called FP60 (www.lubecontrol.com) for about the last 1300 miles. This stuff has gotten great reviews over at BITOG, for cleaning the entire fuel system, as well as the combustion chambers.

Anyway, over the last couple hundred miles I've noticed that the engine in my truck has been running really well, with improved response, freer revving and more power. Then, today, I filled up my tank and checked my mileage, and I got 9.75 mpg , by FAR the best I've ever gotten with this truck.

All I can say is that the stuff I mentioned above flat out works. I bought this truck used, with 98,000 miles on it, and it has the original engine and trans in it. Now, with 100,400 miles on it, it is running really strong. What I have done is start with fresh spark plugs, distributor cap and rotor, change all the fuel filters, and then use the products I mentioned above.

I hope this helps some others who are trying to get the most from their older trucks. With 460's, we can use all the help we can get, in terms of fuel economy.

 

Thats great!! I bet you could tweak 10+ out of it if you kept at it, but 3 solid MPG with just some additives and a tune up is awesome

 

Lots of views, but no thoughts or comments or personal experiences?

I must have phrased my post wrong or somethin'.

 

Sounded like a FYI thread, you know, out there to offer help not ask for it I just wanted to congratulate you, I'm going to push for 10 mpg in my '78, and need all the luck, tips and tricks this forum can offer

 

Oh to get 9.75 MPG out of my 18,000# Class "A" motorhome with a 460 EFI. I would drool to get that much. I am lucky to get 7.5 MPG when not towing a trailer or my tracker.

However right now, I am working on getting my cooling system down to a managable 195*. It wants to run up to 210* most of the time. I would like to get down to 195* since that is the thermostat that I am running.

"Doc"

 

Doc,
Try putting in a 185* thermostat. Your M/H will run about 10-15* higher than the rated temp on your thermostat and that is normal. If changing the thermostat to a lower rating doesnt help, try flushing the cooling system and checking the engine timing.

 

210 is pretty much perfect, it gives you good heat in the winter, plus thats the range 460's run best in.....mine has ran from 230 - 260 degrees for years until i recently unclogged my water jackets during the minor rebuild i did...now it sits at 210 and loves it!!! its when you get over 240 degrees you have to worry about old hoses and weak radiators giving out under the pressure, but if they are all in good shape they can handle the temp being a little high.....

 

Higher temps also help the fuel burn better.

 

Could be that these products removed some of the carbon deposits from critical areas in your engine.

Another one that I have very good experience with is Techron Concentrate. My testing wasn't about fuel economy, though. It was about power restoration. Dirty intake valves can lose you 5-6% of your peak power. This stuff can clean the intake valves and get you to within pretty close of brand new clean intake valves and ports.

For you, your mileage gains probably came from the cleaning of carburetor deposits.

Just my thoughts...

 

I concur, MLF! I've used Techron in the beast and it really helped, and yes, ARX probably did clean carbon and deposits out of the engine - it's known to clean the ring packs and increase compression.

 

hey dave, i have an 86 f250 with a 750 vac sec holley with about 130k miles.
Recent carb rebuild and all I mange to get out of this beast is 5-6mpg. Could be my driving foot that is the main cause, but hearing that your truck started out like mine...
I am gonna check the sites that you linked. I have tried a could of tanks dosed with acetone, and one with techtron. Question, how long did you run with your additives? How would you describe the best "treatment" plan Dr. ??? Thanks Dave

 

barca_texas, the most important stuff is the Auto-Rx (ARX). You'll end up in the ARX process for 7,000 miles, if you have over 100K on your engine, which you do. When you're done, you're engine will truly be clean.

I recommend that you begin using FP60 right away in each tank of fuel. Initially, start with 3 oz. per 5 gal. of fuel, and after several tanks, scale back to 1 oz. per 5 gal. of fuel. FP will give you fairly quick, measurable results.

Be patient and follow this regimen, and unless your engine has mechanical problems, you'll be happy with the results.