I have a 2002 E350 15 passenger XLT. It has 88,000 miles on it.

I'm pretty sure that my van used to get ~15 mpg in city or highway driving with A/C or without A/C being used.

I have recently changed spark plugs (COP), plug boots, fuel filter, oil, oil filter. I reset the computer after the spark plug change.

I have also changed front brakes, and shocks.

The only thing different than usual is the following:

1) I have allowed the air intake to be from the engine instead of outside cold air. Theoretically this should make the engine do less work since the air is already hot.
2) I have switched to 15W/40 Mobil Delvac from the thinner oil (5W/20).
3) I am using a Donaldson oil filter that I bought from a hydraulics shop. It cross referenced with the appropriate sized crappy Fram filter.

I have run only 1 full tank of gas since all of the changes above.

 

The thicker oil is NOT helping anything, get rid of it and use the 5w20 spec'd in the manual. The mod motors have a LOT tighter clearances than the old pushrod motors. There is no need for the thicker oil. The hot air from the engine bay is actually robbing horsepower, the cooler the air stays the better it is at burning the fuel. Use a motorcraft oil filter, they're ~$3 at any store (wal mart or the parts store). And one tank of fuel is not a good way to determine fuel mileage. You might notice a decrease on one tank and then the next all will be well. It depends on fuel quality and what your particular vehicle likes. I've had really good luck with BP/AMOCO fuels in my grand marquis, but my LTD only liked sunoco fuels.

 

I agree, thicker oil is a terrible idea along with having the air filter to draw in the hot engine bay air, what gave you that idea, have you not seen the improvements given by cold air kits, WTF made you thing hot is better.
I have a 99 E-350 ext with 5.4, it has never gotten 15 city, thats the hwy mileage, city is 9-11, and no more, a friends newer company vans are the same, what engine do you have that is making this imaginary number?

 

NOW NOW guys take it easy. not everyone is mechanically inclined and a car nerd to know certain things. doing that many changes anything could cause bad mileage. and maples01 just cause you never have gotten that mileage no need to call him a liar other variables come into play like how you drive. on a trip to NM from Dallas to Lubbock i averages 20 MPG but from Lubbock to Albuquerque while following my aunt in her F250 going 65-70 i got it up to 26. but otherwise i average 18-19 and this is a mid size SUV. even according to fueleconomy.org it shows that van should get 12-16 . But yeah thicker oil is stupid and in a world where their are hood scoops, cold air intakes, Intercoolers and physics i don't understand the hot air works better statement where would you come across that

 

It's not just me, I've heard from others, 15 is just unheard of for city driving.

 

Well I guess my van is just special.

Go to Mileage Testing
to get an education and actually learn something.

You'll be glad you did!

Ta ta.....

 

The oil is the big factor here. The engine actually has to work harder to pump the oil. A regular off the shelf motorcraft filter is more than enough for a filter. It may be in need of a tune up as well. I'd only use autolite platinums or motorcraft platinums as the bosch plugs are JUNK.

 

Learn something from that idiocy, overfill the pan, go ahead, you'll blow the front and rear seal.
Heavier oil causing better mileage, and being better for it, guess the manufacture is clueless, they suggest 5W30 in the modular engines.

 

Actually use of anything heavier than 5w20 in the new mod motors will void the warranty. Ford shelled out big bucks in the early 90s when they first came out, they spec'd 5w30 and a lot of people said "I don't want that watery lookin' oil in my engine!" so they used 10w30 in them. Mileage went down and with the tighter clearances in the motors they actually had engine failures do to loss of oiling.

 

Wow the guy that wrote that article is totally delusional. I'm sorry, but that article is pure bunk.

 

Yes, I see what you mean.

The fellow that wrote the article has only been doing these tests for 50 years and we know the oil and car companies have our best interest at heart.

In order to wake up out of your Orwellian sleep I would recommend you watch the documentary "Who killed the Electric Car".

You'll be glad you did.....

 

Apparently you are really gullible, or paranoid, or both, and have no idea of how an internal combustion engine works. I'll leave it at that. Don't complain about poor mileage after changing to an absurdly thick oil for a engine (makes the engine actually have to do more work per revolution using MORE fuel), and sucking in warm air (less dense, therefore less oxygen concetration). I think that if you put the stock air intake back on AND change the oil back to 5w20 or 5w30 your mileage will come right back. These are ~$40k beasts it's in the CAR COMPANY'S (IE FORD'S) best interest to do everything to get the best mileage out them otherwise people will go to another brand for their needs.

 

When you get one of these know it all pages, where much of the information is FALSE, at least check their domain information. After seeing torco all over that page, I decided to check the domain registration. HA! lendamerica.com That page, imo, is nothing more then a blog to increase sales for troco.

> 1) I have allowed the air intake to be from the engine instead of outside cold air.

Bad, cooler air is better. Cooler air = denser air = more power = better mpg

2) I have switched to 15W/40 Mobil Delvac from the thinner oil (5W/20).

Big mistake in a modular motor. Even bigger mistake trying to replace heads or worse in a later rmodel van.

3) I am using a Donaldson oil filter that I bought from a hydraulics shop. It cross referenced with the appropriate sized crappy Fram filter.

What makes you think a Donaldson filter is any better then a WIX? Or a Fram?

Just put a Motorcraft filter on it.

Replacement spark plugs might not be long enough to reach the spring inside the boot properly. I have seen bad running because of it and had to replace the spark plugs.

 

Wow, maybe I'll try some of that advice here on my farm. Sure would be nice to just skip planting, fertilization and cultivating to be able to go directly to harvesting. Just think how much fuel that will save!!

 

Ha ha ha ha ..... ummmmm... I don't get it......