coolride

Hi,
I have an 03 f150 4x4 shortbox. Has stock tires on it. 16 inch all seasons.
5 speed manual. 4.2L v6. I don't know the rear end gearing but I suspect its a 3.55? It cruises pretty fast at fairly low rpms at highway speeds.
The truck has 76000 miles, the engine is a reman with about 40,000. Runs good, it may need a set of plugs now as they were new when engine was new.
I run almost 90% highway. I ran the truck a couple weeks after replacing the dead engine with this used reman.
I checked the mileage on the last tank of gas, I did 13.26MPG on this last tank.
I've driven a lot of f150 and f250s with 5.4l automatic ext cabs that easily got 14/15 all day long. So I guess I can say I really expected a bit better out of the old v6?! I had one in a 2000 that was 2wd, got 17/18 all the time. I have no CEL, good cats, good air filter (stock), exhaust is stock cats with a glass pack. No other mods. New PCM just before engine replacement with lastest updates.
Just curious, anyone do anything to increase MPGs? I don't beat the truck but I'm not driving like a little old lady either! lol

coolride

thanks for all the input. lol!

4.2f1502002

I get about 15 mpg average a week driving to school and work every day. I don't drive with a heavy foot and that's all I manage to get. When I have my lawn care trailer hitched up with everything it's about 12 mpg. I do have a 2wd 4.2 supercab automatic and the only "performance" mod I did was a magnaflow 3" single in 2.5" dual out exhaust. I might be due for a tune up so I could see maybe 1-2 miles more a gallon afterwards but who knows.

Carcrazygts2

4.2 v6 with 4wd? Thats about normal.

coolride

Sounds like I am in the average range. Seems there's no point buying the v6. Less power than the v8 and basically the same to worse mpg.
I own it now. lol so I will just be happy it runs good and that gas prices have dropped a bit.
Thanks guys

coolride

Has anyone done the gotts mod? Did it help mileage or power any?
Just curious. I have an extra air filter housing and I am thinking of doing it to see if it does anything for the truck.

coolride

Update : so I took my extra air filter housing and I cut the end off that goes out to the fender. I have an opening close to 4 inches now. I didn't bother with the pcv pipe yet as its still under 50 degrees here and intake air temp is no concern. I just wanted to see if it did anything for me. So as far as how the truck runs, I can't really say anything is very different. Possibly at the higher rpms but nothing noticeable for normal driving. As far as fuel economy it did seem to bump the MPG up just a hair but I will go another week and see if it is consistent. It appears I gained a half a mile per gallon. I went from 13.3 to 13.8. Shes a real gas sipper. lol the MPG sucks so bad that I'm not sure a half MPG is awesome, but looking at it as a percentage on 13 mpg isn't bad if it holds to be true.
So does it really give you much improvement? Not so sure. Nothing very obvious anyhow. Easy thing to do to test it yourself, just pull out the rubber boot that goes into the fender. Without changing anything else your air intake port goes from 1 3/4 inch to almost 3 inch, basically the size of the port at the throttle plate. So my thoughts, opening it up much over that probably won't help you a lot anyway, but heck, if it gives you even just half a mile per gallon improvement then it is an easy thing to try. Less money to the gas station, more money other mods. lol
Some people did say to try disconnecting battery to erase PCM learned memory but I didn't do that. I'm thinking the truck will learn the new air flow over time, and maybe that is one reason I didn't get a big AHAH moment?

coolride

My other thought, if you want MPG, don't bother wit ha V6. The V-8s get the same or better MPG and are a lot more capable of towing and hauling as well as much more fun to drive as they have power to cruise at any speed.
This will be my last truck with a V6. Unless I can buy one that can actually get decent mileage. I'm sure the new eco boosts are better that this old ride, haven't driven one so can't say. I say go a V8. Or of MPG is important, drive a VW, and use the V8 truck on weekends, lol

anotherfordguy

My old 4.2 2WD auto only got about 13mpg city 16mpg highway. Roughly 14-15 combined. That wasn't babying but it wasn't hot rodding it either. I get that mileage with e85 on my 5.0 now. with 87 much better. New V6's are better but honestly V8's are the way to go. With ecoboosts its either eco or boost. No in-between.

coolride

I figure I will either go for a small truck with a 4 banger next time if I want MPGs or just go big with the V8 if I actually need to haul or tow anything. Trying to meet in the middle with a v6 just hasn't ever worked out. My older Fords with the 300 inline 6 got better than this 03 with a v6. And the older trucks look cooler, by older I mean 70's, early 80's.
Can't even get an F150 with a manual trans anymore. Probably going new Toyota next time