if tow rates are base on weight of your truck. why so must diff in the 4.6 and 5.4 when thier both 1/2 tons and amost the truck,i can see if it based on power only,any one know fur sure becaue i don't.

 

I do not understand your question at all, but I'm guessing this might help - the 4.6 has a 8.8" differential and the 5.4 has a 9.75" differential. The 9.75 is stronger.

 

Thats the best I can do with it without re-writing everything.

 

That's kinda what I was thinking he meant. It's not based only on power.

 

Tow ratings are based on lots of things, the weight of the truck has little influence on it.

Power/torque, gear strength and ratio, transmission, springs, tires, brakes, frame, bushings, shocks, etc, all effect tow rating. Changing any of those to improve towing only helps improve how the vehicle tows within the MFR specifications and does not change any ratings.

 

very confused

 

The 'tow ratings' for any truck are really only attainable in a 'perfect world' scenario.. The manufactures rate each truck based on it's drive train and it's body configuration for the most part... Where the main difference in 'tow ratings' are seen is when there are differences in the drive train.

For example, a plain jane F150 with a 4.6 auto in it is going to have an x 'tow rating'. Same exact truck with a 5.4 and it's going to have xy 'tow rating', based on the drive train difference in the engine size. Another example can be where the rear end gear is different. Say a 3.55 compared to a 3.73. Even on those trucks with the same engine, a 3.55 will have a slightly lower 'tow rating' then the one with the 3.73.

Then you start getting into the cab configurations. Reg cab, Ext Cab, Super Crew. Different bed lengths, etc.. From what I can tell, Ford has some sort of rating for each drivetrain combo. Then they have some sort of 'curb weight' for each cab configuration and bed length. Each cab configuration is going to weigh a bit different from the others, so subtracting that curb weight from the 'tow rating', gets them their final 'tow rating' for that specific combo...

Now, comes the part where the real world is going to differ from that perfect world... Once you have your drive train and your cab conf all figured out, now you start adding the various trim and package options that are going to add additional weight to the truck, which in turn will reduce that listed 'tow rating' because those trim and package options aren't part of the listed 'tow rating'... Confused yet??

Now, you add your stuff, passengers, their stuff and whatever else suits your fancy, and this adds even more weight to the truck. What's not been mentioned in all of this so far is that your truck has set gross weight limits of it's own. These are the trucks GVWR (Gross Vehicle Weight Rating) and the front and rear GAWR (Gross Axle Weight Rating). All that stuff from above adds to the trucks weight, but the gross vehicle ratings remain the same, thus reducing what you can effectively tow compared to that original 'tow rating', because none of it was considered when the 'tow rating' was listed...

If you have a truck with a GVWR of say #6250 (mine for example), take it to a scale and weigh it (lets not worry about the axle weights, but that IS another important thing to watch for!) and you come out with a weight ticket of say #5300... Subtract that from the GVWR and you only have an additional #950 that you can haul in the truck.

The tongue weight of the trailer adds to this, so if you have a #750 tongue weight trailer, hope you only have another #200 of other stuff, as you have now reached your trucks GVWR and technically, that's it, you are done as far as loading up any more stuff in the truck. Now, whatever your trailer weighs is now it's max tow rating, because you've essentially maxed out one of your trucks other weight ratings.. So, it doesn't matter if the listed 'tow rating' is #20,000, if a #7500 trailer puts your truck over it's other ratings, then too bad, your 'tow rating' is now #7500....

In most cases, a half ton truck will reach it's GVWR and or it's GAWR before you get to it's 'tow rating'.. Can you tow over your trucks GVWR and or it's GAWR?? Sure, the wheels won't just pop off or the engine won't blow up, but you will be compounding the wear and tear factor on it quicker, so that one, two or six trips might not have anything happen, but as time goes on, who knows what it's doing internally on any part??

So, whoever has the lightest truck can have the higher 'tow rating' for the most part, but I don't think I'd want to be driving a #5000 1/2 ton truck with a #10,000 trailer behind it either!

Just my take on it!

Mitch

 

plus, you must take in account of the varying tranny's

 

With very few exceptions, all automatic F-150's from the past 8 years or so have the same transmission in any particular year. The manual transmissions have a lot lower tow rating than the automatic.