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Ford v10 Mileage

I have a 2003 Ford F250 4wd with an automatic transmission and 3:73 gears. It has low mileage and I want to keep it. How can I improve the gas mileage? I have researched the following modifications on the internet:

1. Cut a hole in the panel in front of the air intake on the air filter. (Force more air into the air filter.

2. Replace the air filter with a high flow filter like a K& N filter.

3. Install a throttle body spacer. (Creates a vortex that improves the air flow into the engine).

4. Install a less restrictive muffler.

Do these modifications increase fuel efficiency, if so how much?

Do these modifications cause any problems?

Thank you


Soldotna AK

None of that will make any noticable difference. You’ll either need to drive downhill all the time or get a far smaller vehicle if you’re only carrying around your own carcass normally. That vehicle would already be increasing mileage here in New England because of the rust-induced weight loss program we have.

1- no, more likely to hurt mpg and/or driveability. You are not an engineer, and the intake was designed by an engineer with sophisticated computer models and tested.

2- no, K&N filter is expensive. An over oiled filter can restrict air flow. So there is a risk you might not handle the filter properly in the cleaning and reoiling process. Cheaper to replace your air filter as a DIY weekend chore.

3- marketing hype, they take your money and you “feel” the difference but it is a placebo effect. After spending the bucks you imagine you get some benefit. Dyno testing shows no difference.

4- very expensive, not likely to recoup your $$$. The main benefit is perhaps a nicer exhaust note, music to your ears. Higher mpg is 0 to minimal. Many drivers like the exhaust sound leading to more push on the gas petal to enjoy the sound - there goes your mpg!

Keep you tire pressures at recommended levels, lighten the load in the bed, drive gently, reduce your cruising speed on the highway. Slowing from 75 mph to 60 will give your much more mpg than 1-4 above.

None of these modifications will make any noticeable difference. The folks who designed your truck have already maxed out the gas mileage, and if any of these tactics made a difference, they would already be done from the factory. That V10 does sound nice with a free flowing muffler, though, which means you probably shouldn’t do anything like that. I once installed a straight piped dual exhaust system on an F250 4X4 with a V10, and the owner reported that his mileage went down to 7 mpg, entirely because he couldn’t keep his foot out of it and loved that sound.

You’ll NEVER recoop the money you pay for those devices with the MARGINAL increase in gas mileage (if any) you’ll get.

Unfortunately, your vehicle was designed from the ground up for power, not fuel economy. Trying to make it fuel efficient would mean a total redesign with new priorities.

Perhaps its time to look for a fuel efficient beater you can drive when you don’t need all that power.

While you’ll read otherwise (mostly on sites selling the devices, or folks justifying their purchases) the comments above are correct.

What I get the the biggest kick out of are the ‘throttle body spacer’ folks. For these to work one has to assume the engine designers are, basically, idiots. If ONLY they had thought to insert a $0.50 spacer in the system! I don’t think so…

That sounds like a 8-10 MPG vehicle, 12 on it’s best day…If you NEED that kind of a vehicle, fine, feed the animal…If you don’t need it, get rid of it…

The most effective thing to improve gas mileage (in my experience) is to drive gently, and slow down. Not only will you be safer, but your mpg will increase considerably. Just driving 65 mph instead of 80mph will save you a considerable amount of gas, will induce less engine stress, and keep you safer.

What you need to do is buy a second vehicle to take the load and miles off of your precious truck.

Lets say that your truck gets 12 mpg on your normal commute to and from work, which is 55 miles each day. With a 5 day work week, and 50 weeks you have to drive to work every year, you have traveled 13,750 miles. That means that you need to buy and burn just under 1146 gallons of gasoline.

Lets say that fuel is $4 per gallon right now where you live.
That means you spend $4584 to drive your truck every year.

Now, lets change your truck over to a motorcycle that gets 50 mpg.
Lets say that you can use it 1/2 the time instead of your truck.
That’s 6,875 miles in a year.
That only needs 137.5 gallons of gas ($550) to get where it’s going, and your truck burns 573 gallons of gas ($2292). This means you just saved $1742 in fuel costs. If you drive the bike more, you save even more money, of course.

If you make the bike do 3/4 of the miles for your commute, you save
$825 for the bike’s fuel tank, $1145 for the truck, which equals a $2614 savings.

So, go find yourself an inexpensive bike, get some insurance, some riding gear, and start saving a real amount of money, instead of trying to make your truck do something it just can’t.


You’d be miles ahead by just buying a smaller car and keeping the truck for when you actually need it.

No difference. If your air filter looks like a bullet to begin with, you don’t have to change it. If it looks like a square foot of filter, you don’t have to change it.

A vortex would push fuel outward, disturbing the blend of fuel to air, possibly creating a demand for… more fuel.

Cutting a hole would reduce air flow when it is needed the most; when you are in motion…

While you are installing a less restrictive muffler, install two less restrictive catalytic converters.

Give up. It isn’t working.

At best those mods (except for 3, which will do nothing) will increase power. The more air you stuff into an engine, the more fuel gets put in to maintain the proper mixture. Mod 1 will make your van significantly louder, and possibly increase a bit of top end horsepower that you won’t notice. Mod 2 will do absolutely nothing except make you have to remember to re-oil your filter periodically. Mod 4 will make your van louder, and depending on how “less restrictive” it is may actually cut power while not saving fuel.

To be honest, you drive a V-10 vehicle with all wheel drive that weighs more than 2 tons. It is never going to be anything remotely approaching fuel efficient.

Agree with all the above. If you have a MAF sensor, the K&N filter can and probably will damage it, so avoid that. Anything that forces more air in will cause more gas to be injected to keep the A/F mixture as close to the ideal ratio as possible.

The less restrictive muffler won’t help, but I don’t think it will hurt either, just a waste of money.

3 tons, V10, automatic, 4wd and 3.73 gears, that is a combination to do a lot of work, but it is also a combination to use a lot of gas. The only thing I can see helping here would be to change the final gear ratio, but you have two differentials so that will be very expensive. I doubt you will ever recover the cost and you will have less power for heavy duty towing or snow plowing.

I don’t know anything about Soldotna, but I imagine that a truck like yours is very useful in most parts of Alaska so getting rid of it is probably not an option. A small econo car for good weather and “grocery getting” is probably your best option. It will not only cut your fuel consumption, but will help extend the useful life of your truck.

it’s probably closer to 4~5 tons