5.0 AWD Mounty upgrade review

[RV Wrench]

5.0 AWD Mounty upgrades for better fuel mileage review

Seems there has been alot of questions about gas mileage upgrades lately (gee, I wonder why?), so I thought I would share a few of the things I have done.

First off, I started with a bone stock '99 Mounty with AWD and 5.0. It had just over 100k on it when I purchased it. I started with about 13/18mpg city/hwy. It actually did about 15mpg average commuting several miles to work and back, but the worse gas mileage (13) was in the dead of winter commuting leas than 3 miles. This engine REALLY runs rich in cold weather when it is not up to temp.

-First mod: synthetic engine oil. I chose to use Shell Rotella T 5w40 synthetic, because I know this is an excellent oil. The only thing I would recommend over it is Mobil 1. I had no mileage increase with this mod, but definately a peace of mind that the engine will live a full life.

-Second mod: K&N drop-in air filter. Little change in mileage or power that I can feel.

-Third mod: ported stock throttle body. Definately a different feel with the throttle (more touchy off idle), but very little fuel mileage increase or noticable power increase. The computer took a few days to adjust.

-Fourth mod: Cat-back exhaust mod. I removed the rear cats and replaced them with 2.25" straight pipes, replaced the stock muffler with a dual 2.25" inlets and single 2.5" outlet. Again, the computer took a few days to adjust. It was initially very rich and gas mileage dropped, but returned to normal once the computer adjusted.

-Fifth mod: Torque monster headers. Top-notch product!!! I got my headers about 2 weeks ago, and they came with the new EGR tube that directly bolts on. Install took about 6 hours on a very HOT afternoon. The heat slowed me down, but the install really went well. I also changed the spark plugs out at the same time, which smoothed the idle nicely. Once again, TOP-NOTCH product. Fit and finish was beautiful. I noticed a little power increase, but I really didnt have time to log any fuel mileage difference or dyno to prove power difference. The engine has a real nice "tinny" sound to it when running now. I did the next mod less than a week after this one. I would also like to note that I found the front two exhaust manifold bolts on both sides of the engine were very LOOSE and obviously leaking past the original exhaust gasket. I would advise any of you that have over 100k miles to check yours if you arent installing headers soon.

-Sixth mod: Xcal 3 from Explorer Express with tunes from Doug at Bamachips. WOW!!! What a difference!! I think this is where all the recent mods came together in beautiful harmony. With the 87 Performance program, my power and fuel mileage instantly jumped up. With the 91 Performance program, she flat out pulls HARD and the engine sounds like an angry swarm of bees.

Two days after I received the Xcal 3, we left on vacation. I took the Mounty and pulled my 2000 pound tent trailer from WA State to Nebraska. At a 60mph average, we were able to maintain about 18mpg. Coming across Nebraska at a 70mph average with a headwind, we only got about 15mpg. The entire trip here we averaged 17.1mpg over a 1500 mile distance. Calculations were based on gallons used per miles driven, not on the vehicles computer reading. Not bad, considering I was pulling a 2000 pound tent trailer!!

Notes of importance:
-speed makes a HUGE difference in mileage. The sweet spot seems to be around 60, but no more than 65mph.
-the Performance tunes seemed to work best for fuel mileage. No apparant difference in mileage between the 87 Performance or 91 Performance, but the 91 Performance definately pulls harder. The 91 Torque tune dropped the mileage and seemed to have no advantage over either tune.
-I accidently chose fuel with 10% Ethanol twice, because I was focused on getting 91 octane. This happened at the same time I was running higher speeds in Nebraska, which could have definately effected the drop in mileage. I will to more testing on the trip back.
-I was running 40psi in my tires.
-Fuel mileage seems to be up about 1.5mpg for city driving. I think the AWD is the culprit that is hurting the city driving so much.

I will be running a little Marvels Mystery Oil in the Mounty on the trip back to see if I can get a little better mileage.

 

[TekMan05]

Ok so Did you order the tuner right off ExplorerExpress. When you did, at what point in the ordering process did you have to provide Vehicle Information. And can they create the tunes for the Torque Monster Headers?? Sorry I have so many questions on The Tuner because Im about to order the XCal next week when I get paid. I just want to be prepared!

 

[RV Wrench]

Yes, I ordered from Explorer Express. I filled out the requested vehicle info and posted it in the "notes" section on the online order form.

Explorer Express just passes the info on to Doug and he fills the order. They were extremely good in filling my order and getting it in the mail the next day so I could have it in time for my trip.

Well, the trip is over now. Covered just over 3,000 miles and averaged somewhere around 17mpg. I know it doesnt sound good, but here is why: Roughly 1,000 miles of that were headed directly into a headwind that was pretty nasty, where I could barely pull over 14mpg. I dont have any exact numbers, but I could tell by the digital readout that on flat ground with no wind, it would hold steady around 19-20mpg. Remember, all of this was with a 2000 pound tent trailer in tow. Not bad, considering I could barely pull 19mpg before the upgrades with no trailer attached.

I also played with the TPS a little on the trip. I found the best fuel mileage and best off-idle throttle transition with the TPS adjusted to 1.01 VDC at idle.

And just one more note: DONT trust the gas pumps that their octane ratings are correct. I found SEVERAL that had "91" octane that pinged just as much as 87 octane on the hotter tunes.

 

[RV Wrench]

I havent noticed ANY change in fuel mileage after the Marvels Mystery oil added to both the gas and engine oil.

I used the Marvels Mystery oil in my Chevy Venture engine oil a few months back, and it didnt help fuel mileage any on that either.

I am not knocking the Marvels in any way, I have seen this stuff bump the compression numbers in an old, tired aircraft engine. I just dont think it is really worth any advantage to an already good condition engine when you are using good engine oil in the first place.

I plan on changing the axle gear oil and transfer case oil with good synthetics soon. Probably wont make any difference, but will give me peace of mind anyway.

Anyone ever noticed any changes by switching to lighter wheels or driveshafts?

 

[RV Wrench]

Yes, I am digging up an old thread. It is mine, after all.

I now have 165k miles on this beast. Here are a few notes:
-I used Marvels at around the 150k mile mark and DID notice a bump in fuel mileage, that seemed to stick even after subsequent oil changes. I suspect it cleaned some carbon buildup in the engine.
-overall fuel mileage is about the same now as it was when I purchased the vehicle stock. I believe this is due to higher mileage and now all the fuel has Ethanol, which makes for crap mileage all on its own. I get about 15 around town and about 18 if I keep the speed under 70 on the freeway.

I gotta say, I was never really a Ford fan until I bought this rig. In the last 60k miles, I have had to do NOTHING but change a TPS and O2 sensors (besides filling the gas tank and changing the oil).

Oh, I also ditched the K&N filter and went back to stock. Something about silicon content in the oil...

I am now looking into doing a full-width SAS, with a 331 stroker.

 

[Greg_DonWindsor]

Shell V-Power does not contain any ethanol. I obtain the greatest fuel economy with this choice of fuel. I have made 2 trips across Canada, and have measured fuel economy at a constant elevation, temperature, and cruise control settings during sometimes having travelled a little more than 1000 miles per day. The difference in V-Power is a mpg increase of up to 2mpg greater than lesser quality fuels. While this is for my 4.0 SOHC, I have friends who drive other vehicles (F150's, BMW 5 series, etc.) all of who have reported similar findings, so I'm sure it wouldn't hurt to try in your truck as well. I haven't done the mod yet, though many forum users have reported significant mpg increases in switching to an electric fan.