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Addons for better mileage?

Has anybody had any experience improving mileage and power with add ons? Is keeping acceleration down to 1500 rpms the best suggestion? When I bought my 2007 ExpyXLT I expected better mileage. (Silly me!) I had previously owned two Ford Vans on 1T frames with 4.5L engines. Their mileages were 12mph city, 14 mph highway, and 9mph pulling my trailer. I bought the Expy because it uses the same engine on a half-ton frame. (It’s a 1/2 ton lighter! I had to get better mileage!) Because it’s a truck, there were no mileage estimates for it. Yeah, I was taking a chance, but people I know who are supposed to know what they’re talking about said, “Make the switch. You’ll be happier!” Well, I got a mixed bag: 10 mph city, 20 mph highway (!), and 9 mph pulling my trailer. I met a guy at a campsite with the same vehicle. He said that he had installed a K&N air filter and a Magna Flow exhaust. He said they improved his mileage and his power, but he had no numbers. (I don’t think the guy knew how to use his on-dash computer read out!) So, besides designing and building a helium-filled frame for the Expy and the trailer to reduce friction, what else can be done?

Power add-on’s and fuel mileage are an oxymoron. If you want more power you must use more fuel. If you want fuel mileage you must use less fuel.

And don’t go by anecdotle statements made by someone at a campsite. I’ve never heard of anyone installing hundreds of dollars of aftermarket components claiming to improve fuel mileage, and when they didn’t deliver brag about it.

Don’t waste your money.


Add on: maybe a couple PSI in the tires; when it is time for new tires, get the skinniest ones spec’d for your vehicle, and a model that gives better MPG (has less rolling resistance.)

I can’t think of anything else to add that will help MPG. K&N filters and aftermarket exhausts are very unlikely to ever pay back the money invested. If they give more power, it is only at max throttle, where you don’t want to be if MPG s your goal.

Take off: wide tires on alloy rims; roof racks, tool boxes… anything else that adds weight or wind resistance.

Add-ons are generally not worth the money spent for extra power or gas mileage. My brother added a cold air intake and throttle body spacer to a Jeep he had, and after driving it the only difference I noticed was more intake noise. He had no comment on the matter. Exhaust changes usually result in more noise, which tempts the driver to use the loud pedal more than necessary, resulting in worse gas mileage. One fault I can see in your question is the reasoning of getting better gas mileage by accelerating very slowly. This is the way to go in stop and go traffic, but for longer stretches and getting up to speed on the highway, you will get the best mileage by accelerating briskly (half to three-quarter pedal) to a reasonable speed and then maintaining that reasonable speed. This is especially true when towing. You will use a whole lot more gas taking two or three miles to get up to highway speed than you would have if you had gotten up to speed within the first half mile.

If those add-ons such as cold air intakes and exhaust changes really worked those add-ons would have already been added on at the factory when they built the vehicle.

The 20 mpg highway indicates you are doing OK and I don’t think a K&N filter and expensive exhaust system will save you enough money to be worth the price you paid for them.

9 mpg with a trailer in tow isn’t bad. You just don’t get decent mpg hauling extra weight and the aerodynamics of a trailer creates a lot more wind drag. When towing start gently, used the downhill grades to build speed, let your speed drop off several mph on the uphills, and slow down to 60 mph on expressways. If you do this you can get 12 - 14 mpg instead of 9.

Around town driving is very dependant on how often and how hard you brake and accelerate. Adjust your in town driving habits to increase your mpg.

Add-ons will only add money to the bank accounts of the companies that sell them. They will lighten the pockets of the people that buy them.

“Because it’s a truck, there were no mileage estimates for it.”

You can do some deductive reasoning. The 2007 2WD model is rated for 12mpg city and 18 MPG highway (It is rated by the EPA, the 4WD model is not). So it would reasonable to expect that the 4WD model would have a 1 or 2 MPG penalty. A good estimate for the expected MPG of a 4WD Expy would be 11 MPG city and maybe 16 on the highway. If youre managing 20 MPG on the highway, then you’re exceeding the EPA estimates for the 2WD model and are getting exceptional highway mileage for that kind of vehicle. 10 MPG city is also in the ballpark for city driving.

I’ll also point out that Ford doesn’t make a 4.5L V8. They make a 4.6L though. Your Expedition has a 5.4L. Additionally the Expy is just as, if not heavier than your previous vans.

The way you drive is probably the single most important change you can make that will effect gas mileage.

Drive gently, keep your tires properly inflated, and keep up on your maintenance.

Unless the '07 you bought was overdue for maintenance or has aggressively treaded tires, there’s not much you can do to improve your mileage. Add ons don’t work. And anyone who says they increased both power and mileage is fooling themselves. More power comes from the ability to put more fuel in the cylinders while still keeping the proper air/fuel ratio…or running rich.

If the trailer you’re pulling is higher than the truck roof, a roof mounted wind deflector might help, but that’s about it.

The best “addon” is a disciplined and sensitive foot. Your driving habits are the most important element in minimizing fuel consumption.

In the past drivers often hooked up a vacuum gauge to the intake manifold. The higher the vacuum, the better the fuel mileage. That’s when cars had carbueretors; I don’t know if it works as well with fuel injection.

I can’t speak for exhaust systems, but I’ve installed home-brewed CAI’s on two vehicles, a 1995 Dodge Dakota and a 1993 Chevrolet Caprice. No difference in mpg, but they both sounded good.

The biggest change in mpg for my Dakota was when I replaced the horrible OEM Goodyears with Dunlops with a more aggressive tread. There was a drop in mpg (1 to 1.5mpg), but the truck handled and drove much better. Lower rolling resistance tires and conservative driving are your best bet. If your truck is 4wd, there is a more parasitic drag in the drivetrain than a 2wd vehicle.

Ed B.

The CAI system I just installed is home-brewed too. I opened the “imitation port” on the car’s front to scoop cold air, created a grill, created a plastic “chamber” behind the new ram intake, removed the OEM snorkle to the air fliter box and attached a 2-1/2" shop vac hose with a velocity cone to where it collects air from the now-slightly -pressurized cold air “chamber”, and removed the sound “filter” from the top of the air filter box. My power above 40 mph (when the air is rammed in) has definitely improved, but my mileage has dropped a bit. Of course, I could get better mileage by disciplining my right foot…

Done properly, a cold air/ram air system does improve pep, but the ones being sold on the open market don’t incorporate the ram air effect, or even a cold air source, into the system and IMHO don’t do much for the money one spends. Mine cost $25. And works. And it uses an OEM filter. No oil for this kid.

Oh, and anything that increases power does not also improve mileage. The two are mutually exclusive.

Has anybody had any experience improving mileage and power with add ons?

Sure, I have. The problem is that by the 1980’s the manufactures, figured it out and those kind of modifications have already been done at the factory.

There is only one add on that I know of that really works. It is called the brick mod because it means putting a brick under the accelerator.

Make that a mental brick not a real one. :slight_smile: