I've got a 5.4 in my '06 F250 and bought my "new to me" truck specifically for this engine equipped with a 6 spd manual transmission. I previously owned a 1/2 ton Chevy ext cab with a 5.3 and an automatic. The 5.3 is listed with lower HP and torque numbers than the 5.4 but it felt a lot more responsive on the highway. My 5.4 is feels like it has quite a bit more power down low, but also feels like it goes flat at highway speeds. I don't have any problems making passes on the highway, but the engine just doesn't feel very impressive compared to the 5.3.
Could this be a case of auto versus manual trans? I know my 5.3 felt weak on the bottom end when towing my big enclosed trailer so I'm thinking my old Chevy was a lot more of a commuter/highway truck than a work truck. In any case, the contractors I work with all have the opinion that the 5.4 is a gutless wonder, especially when it's hooked to an auto. One of our work trucks is an Expedition with a 5.4 and it does not feel as strong at highway speeds as my 5.3 did. Why does the 5.4 not feel very impressive?
well i dunno about gutless as the shelby and gt 40 used them .... maybe like so many others it's the program in the ecu . get a tuner or chip as it may be and it might wake it up . also the usual bolt ons like a cold air kit , exhaust , etc. will probably help . one always has to remember that everything is a compromise when these were built new for the job required , emissions , etc. so don't expect it too act like a monster capable of ripping the heads off of all passing furrin' cars cause it's not going too .
Rear end gear ratio?
Effective gear ratio (transmission and rear end gear)?
Weight (curb and loaded)?
Tire and rim size?
RPMs at crusing speed?
If you want to wake the F250 up, I suugest you contact Mike at 5startuning.com about an SCT programmer with custom tunes.
Personally I wouldn't bother with the warmer-air-than-stock after market intake (unless you are simply looking for under the hood bling) or exhaust (unless you're looking for a meaner sound - which can increase butt dyno sensitivity).
I hadn't thought about the weight. My Ford is definitely a heavier duty truck than my Chevy was. My Chevy had 3.73 gears but I don't know what my F250 has? I figured our Expedition at work would compare pretty well to my Chevy. It just feels like it has less power and speed up past 55 than the Chevy.
I've noticed with my F250, it feels like it really likes to rev out but there is no redline on the tach so I don't know how high I can safely wind it out? I'm sure the limiter will kick in to prevent blowing it up but sometimes I think I'm winding it out to far when passing people. Does this engine make its best power well about 3000 rpm?
Gutless!....don't loose sight of the fact that the 5.4 is a true "truck" engine. A long stroke engine (stroke bigger than bore) to give it lots of torque at low rpms. The Chev engine is not. Yeah the 5.4 does wheeze out at highway speeds but at low speed and rpm it is a brut for its size.
Ok wait a minute! Don't go by seat of the pants. 2 of my buddies lined up low mileage trucks a 2004 f150 6100lbs and a 2005 (5.3)chevy pickup 4x4 6000lbs. After driving the f150 and driving in the chevy my money was on the chevy. Dead even to 75mph, f150 pulled ahead over 75. Both trucks stock.
My excursion got beat bad by both but that doesn't count.
I'm not sure I understand the test? The Chevy was a 6.2L and it won, the Toyota with a 5.7 came in 2nd and the Ford was 5th. I thought GM offered a 6.0 for their gas motor?
I know what you are saying, I like the power my Ford makes down low. Maybe it's a case of me being greedy? I just want that same feeling of power all the way thru the powerband? This thread has been helpful because the graph quantifies what I thought. The further I rev the 5.4, the more power it seems to make. I think I just need to rev the 5.4 out a lot more than I'm doing. I think I've been short shifting it too much and running the motor at too low of RPM's?
The 5.3 is gutless from idle till mid range rpm, where the power comes alive. The 5.4 has stump pulling power and torque from idle till mid range rpm, where it becomes gutless and asthmatic. For trailer towing, low end torque and throttle response, the 5.4 is better. For fuel economy and spirited revving power, and exhaust note, the 5.3 is better.