I have a 2003 F150 Crew Cab, 5.4 with 6600 tow package. I have a 5000 lb trailer and would like to increase power and economy to better climb the 6 & 7% hills. I’d like to know if anyone has had experience or suggestions on the following items including specific brands and increase in fuel mileage and horsepower: Headers, cool air intake, duel exhaust (is stainless really worth the extra $) and Hypertech Power Programmer or other management system. Thanks

 

Duals may help alittle since towing a trailer...mainly IMO for good looks, but I would definately go stainless, trust me just keep em clean they hold up great! Cold air intake...save your money put it do better use. Your stock intake works just great! I have a Superchips on my 02 5.4L, prob great for towing with the TOW setting...but I mainly use mine to recalibrate my speedo for 35s and leave it on the basic 87oct setting. You will hear many different opinions on programmers. Thats prob $400 that still might be better used. Your best bang for buck IMO are GEARS! Espec if towing a trailer. Go...4.56 or 4.10 at the least. What gears do you have now? I would say gears are your best bet!!!

 

like stang 302 said.......if you want to climb hills better then gear it up......4.10s is good set ......4.56 may be a little steap especially if you have stock tire size on.....thast going to make the biggest difference......exhaust your not going to notice much except the wonderfull rumble of a V8......K&N=RIP OFF....waste of money......no gain there no matter what people say unless your truck is supercharged or somethgin like that where you actually need more air into the motor....i'd go with a preditor tuner....that'll help you out too....thats what i would do

good luck

 

I have 3.55 limited slip. Wouldn't 4.56 drop my mileage even more? I also drive 100 miles roundtrip so economy is an issue as well. I thought letting in breath better and exhaust better would help, but from what you've said, not by much. Sounds like chip might be the way to go.

 

Thanks for the advice. I love the rumble, but I want real results not cosmetics or a thoaty tone. I'm not sure about the gears (3.55's now) due to my daily commute, but I've looked into the preditor as perhaps my solution. Thanks again.

 

gears would probable drop MGP for sure......if you need it for daily commute also i'd stick with the 3.55 gears.....preditor will help out though

 

The K&N lets more air into the inlet tube, but it gets backed up at the stock throttle body opening. IMO, that's why cold air intakes don't do much for you. Also, I tow my trailer with my 99 LD 250 5.4 with a superchips. I leave it on 91 Octane Performance for everything. Reason being that going up a paritcularly steep hill, my truck would stay in first gear at 45 mph on the way up due to the shift point set up for the TOW PERFORMANCE setting. It tows just fine with the 91 PERFORMANCE setting. I commute 152 miles daily with this truck also, and if I keep my foot out of it, i get around 14.5.

 

Thanks!!!!

 

4.56 gears would be too much for stock wheels and tires...agreed! Although, pulling a trailer, gears will help your mileage IMO. Maybee 4.10...or a 3.73 would better fit you, although 3.73 might not be much of an improvement for the money. You will be surprised at how mileage might increase with gears...due to the fact that the motor and tranny dont work as hard to pull your load. As well as also "in town" driving or your daily commute...the tranny will not shift as much. Do a search on here...and I bet you find others who have "mileage increases" with gears! Just my thoughts!

 

I'm having a brain freeze, if I change the gear ratio from 3.55's to lets say 4.10's than the motor is working less to transfer power to the tires. The higher the ratio, the "taller" the gear? I was thinking the other way, that a more agressive gear would make it pull better up the hills, but kill my MPH, instead it would be taller gears to get more from the horsepower I already have. Do I have it right or should I go take a nap and start all over??!!

 

Going to a 4.10 will not kill your MPH. It will help you hold your MPH as your climbing those hills. If you pull better up the hills as you say, your rpms are "in good range" and will hold your speed, not loose it! Now lets say if you do go to a 4.56 or even numerically higher...your rpms will jump up fast but wont have much speed "so to say" (like you were saying). Now 4.56 wont really hurt speed in our trucks I dont believe...too many guys have them on here and brag about how good they are. Although as you said, consider this...Tractor sled pulling, or 1/8 mile drag racers may run a gear up above 4.56 even into the 5s. They can get there super fast...but once they reach a certain point, they cant go any faster! Now lets say you went to like a 3.08 gear or lower numerically...its gonna take you awhile to speed up, but you could prob run 140mph in our trucks...haha Make sense?

 

OK, I get you. I actully meant MPG when I wrote MPH. The lower the gear numerically the taller it is. If it was higher, it would be lower. 3.08 would be super tall, take a while to get there but we could do the 140 you were talking about! The 4.56's like a drag gear or a ten speed bike tiny gear, gets you there fast but you level out and can't go no more. The 4.10's would be a good comprimise from the 3.55's to give a bit smaller gear to get up the hill. I'd loose a little MPG but not MPH. Does grasshoppa understand better now? LOL

 

Haha...I think were both on the same page! 4.10 would be good I still believe, I still think you will get BETTER MPG in city driving due to the not shifting as much, etc etc. I personally think our 3.55s suck. 3.73 should have been stock, not an option in our trucks IMO. But yes again, loose alittle mpg on highway driving, due to more rpms. Back to though, with 4.10s I still think you would get better MPG all around while pulling the trailer. Just something to think about!

 

Using the 4.10's, while towing, you shouldn't have to lock out OD so that will help the mileage. My Predator programmer gave me better towing power and it picked up 1.5mpg on the hwy. I too have 3.55's with 31.7" tall tires (265/70r17). If I had the money to change the front and rear differentials, I would change them to 4.10's. I often tow about 7000lbs myself.

 

Excellent. I may just have to go to the 4.10's. Thanks.