Towing with f150

[Doll86]

Have a question,I am looking at upgrading to a different camper and I am looking at a Rockwood Signature Ultra Lite 8313ss I was wondering if this was to much camper.Previous owner said they pulled with f150 all over (Bristol race) My truck is a 2004 f150 fx4 4 door ext cab gvwr 7150 front gawr 3750 back 3850 wb 133 has 5.5 bed 3.73 axle which I got from owners manual along with 13000 towing cap including truck wt. I do have after market brake control and thinking of adding air assist. The camper has a hitch wt. of 730 dry wt 6204 which I know doesnt really matter because I would be loading camper with supplies,It has gvwr of 7730 camper has wt distrubuiton and sway control hitch .I would be towing it in Ohio (flat land) and we usaully stay within 3 hr drive of home and camp about 4 times a year. I am in the market for F250 but they are hard to find for the right $ and condition.Does anyone have any thoughts?

[caleb]

Well, if I am reading your post correctly on the truck's capacities, total capacity is 13000 INCLUDING the truck weight? So GVWR is 7150, so 13K-7150=5850 towing capacity. At 6204 dry weight (actual weight will likely be 7K+), I'd say it's far too heavy for your truck. However, I may have misunderstood your capacities.

[Doll86]

I got the 7150 GVWR from door rail I think thats that maxload for truck including truck wt. Wt.you can haul in bed? The wt of truck I would guess to be around 5500-6000 lbs empty.So I think it would be 13000Towing cap-6000truck wt=7000 I was wondering if anyone else pulls these Rockwood Ultra Lites with 1/2 ton trucks

[caleb]

Originally Posted by Doll86

I got the 7150 GVWR from door rail I think thats that maxload for truck including truck wt. Wt.you can haul in bed? The wt of truck I would guess to be around 5500-6000 lbs empty.So I think it would be 13000Towing cap-6000truck wt=7000 I was wondering if anyone else pulls these Rockwood Ultra Lites with 1/2 ton trucks

Right, I understand what gvwr is. You have to consider in gvwr all your passengers, fuel, and then the tongue weight of your trailer (10%). I still think you're pushing it if you want you and your family to be safe.

[Doll86]

How do you fiqure the 10% tongue wt? So if I am looking for a new truck take the gvwr(from door rail)-towing # in owners manual and that is the weight I want to stay around?thanks for your help!

[MtnGuy]

Comparing it to my F150 with a 145" wheelbase and 9300 lb. tow rating, I feel that pulling my SV 263 weighing in at 5500 lbs. and 28.5' overall, is about the maximum trailer that I would consider. Most of my figures are well in line, except I am nearing my GVWR with a 559 lb. listed tongue weight that has grown to around 700 lbs. ready to camp. With a listed tongue weight of 790 lbs. on the 8313S, that is probably going to grow to around 1000 lbs. ready to camp, adding to the gross weight of the truck. The hitch on that truck is probably not rated for that, either.

The OPer failed to mention the tow rating and what engine is in the truck. The tow rating is either 6800 for the 4.6 L, or 7600 lbs. for th3 5.4 L engine. Even with the 5.4 L, the trailer gross weight is over 1000 lbs. more than the tow capacity of the truck.

More important than all of the weight numbers, is the safety concerns with pulling a 34' trailer with a 133" wheelbase vehicle.....that is 1 long trailer.

IMHO, the OPer needs to look for a much smaller trailer.

[caleb]

Originally Posted by Doll86

How do you fiqure the 10% tongue wt? So if I am looking for a new truck take the gvwr(from door rail)-towing # in owners manual and that is the weight I want to stay around?thanks for your help!

A proper setup trailer will have 10% tongue weight. This will make it so the trailer tows as good as it can. This is 10% of the trailer weight, so for a 7000lb trailer, you would want 700lb tongue weight. That tongue weight adds directly to your carring capacity (maybe I should say subtracts from it). It's like throwing 700lbs of bricks in your bed.

[caleb]

Originally Posted by mtnguy

Comparing it to my F150 with a 145" wheelbase and 9300 lb. tow rating, I feel that pulling my SV 263 weighing in at 5500 lbs. and 28.5' overall, is about the maximum trailer that I would consider. Most of my figures are well in line, except I am nearing my GVWR with a 559 lb. listed tongue weight that has grown to around 700 lbs. ready to camp. With a listed tongue weight of 790 lbs. on the 8313S, that is probably going to grow to around 1000 lbs. ready to camp, adding to the gross weight of the truck. The hitch on that truck is probably not rated for that, either.

The OPer failed to mention the tow rating and what engine is in the truck. The tow rating is either 6800 for the 4.6 L, or 7600 lbs. for th3 5.4 L engine. Even with the 5.4 L, the trailer gross weight is over 1000 lbs. more than the tow capacity of the truck.

More important than all of the weight numbers, is the safety concerns with pulling a 34' trailer with a 133" wheelbase vehicle.....that is 1 long trailer.

IMHO, the OPer needs to look for a much smaller trailer.

Yeah, I'm at 146" WB with my Tundra CrewMax (10,700 towing capacity) and I'm towing a Puma 30KFB (34'9" total length) and I'd definitely say I'm at my max length. It tows great, but I'd hate to go any longer.

[jimbob]

I tow a rockwood 8314SS 2008 with a 2003 F150 super cab mainly in michigan flatland it has a5.4 liter 2 wheel drive.Usually only tow about 200 miles handles as well as the 30 foot 1989 trailer I had because of lighweight construction.I have had no problems your trailer looks like it has more tounge weight 134lbs more and total 357lbs more.I would not think that would be a problem with tortion bars on your hitch.Wish you luck hope this helps
JIMBOB

[kalik282]

Originally Posted by Doll86

Have a question,I am looking at upgrading to a different camper and I am looking at a Rockwood Signature Ultra Lite 8313ss I was wondering if this was to much camper.Previous owner said they pulled with f150 all over (Bristol race) My truck is a 2004 f150 fx4 4 door ext cab gvwr 7150 front gawr 3750 back 3850 wb 133 has 5.5 bed 3.73 axle which I got from owners manual along with 13000 towing cap including truck wt. I do have after market brake control and thinking of adding air assist. The camper has a hitch wt. of 730 dry wt 6204 which I know doesnt really matter because I would be loading camper with supplies,It has gvwr of 7730 camper has wt distrubuiton and sway control hitch .I would be towing it in Ohio (flat land) and we usaully stay within 3 hr drive of home and camp about 4 times a year. I am in the market for F250 but they are hard to find for the right $ and condition.Does anyone have any thoughts?

Try this...The more accurate your numbers are, the better the overall accuracy. (IE: Don't guess at the numbers. If you don't know them, look them up. Google is your friend!)

Travel Trailer Weight Calculator

John

[Labzy]

Ok, I'm real new also, and I have learned alot from the helpfull guys on here.
So, you have come to the right place for guidance!!!!!
I also was told faulty information about towing stats etc. from trailer and auto dealers.
But I guess if I always remembered the addage "mediocrity cuts across all professions" I wouldn't have been so surprised by it.
This is my understanding about trailer ratings as learned from this forum and my good friend Google.

To determine what your truck can handle, first you need to know what the Trucks GVWR is, and from there determine what your payload capacity is.
So lets try this and fill in the blanks with your numbers.

(GVWR of Truck) 7150lbs - Curb weight = _______lbs of payload
_______lbs of Payload - Passengers - Cargo - Tongue Weight = _______lbs
This last number must be higher than 0 if it isn't you are over the GVWR of the truck, and you better look at a different trailer.
If you are all good here, let's move on.
GCVWR = 13,000lbs
13,000lbs - 7730 (GVWR of Trailer) = 5270lbs Truck weight (which is too high)

If you take your 13,000lbs and subtract the number that you calculated on the 2nd line, that to me would be a more correct GVWR of a possible trailer (factoring in a lower tongue weight of course)

Please correct me if I'm wrong

[youroo]

Go to website (Changears.com) you supply the INFO and they tell you,No guessing! Youroo!!

[Doll86]

Could not find changears.com website typed in and googled nothing came up?

[sherdep]

he must have meant changingears.com

Travel Trailer Weight Calculator

[youroo]

Originally Posted by sherdep

he must have meant changingears.com

Travel Trailer Weight Calculator

Yes thats it, Thanks. Youroo!!

[campnqueen]

Go have your truck weighed to see the REALLY weight loaded (gas too)...13k is NOT what a F150 can haul... I have one! Also depends on the accessories too... is it a 4 door? Do you have a bigger/ heavier rear axle? Truck manufactures tend to over estimate their towing capacity.

[prof_fate]

Originally Posted by campnqueen

Truck manufactures tend to over estimate their towing capacity.

Ain't that the truth! And google isn't helpful on this subject as you'll always find the max tow rating a vehicle can handle under ideal conditions/options.

The difference between ideal and reality on my expedition is 1500 lbs. Things I didn't find on the net that are in the owners manual that affect tow rating are rim/tire size. Bigger rims lower the tow rating (cause the lower the load rating). 4x4 will lower tow rating (more weight on tow vehicle), options as mentioned affect it, and then there's the little paragraph that says "trailer frontal area not to exceed 60 sf"

Since the expy is F150 based i'd imagine it's about the same for you truck.

13,000 - truck wt empty (5400?) leaves 7600. Add in cargo (people, pets, gas, firewood, HITCH, etc) - 800lbs? That comes off the 7600 leaving 6800 lbs for the trailer and everything you put in the trailer.

[campnqueen]

Pro fate - "trailer frontal area not to exceed 60 sf"? is this for a fifth wheel? I am just guessing....Never heard this term before.

[prof_fate]

Originally Posted by campnqueen

Pro fate - "trailer frontal area not to exceed 60 sf"? is this for a fifth wheel? I am just guessing....Never heard this term before.

Thats in the book for the expedition, an SUV so it can't be for a fifth wheel. Makes sense regarding wind resistance on the highway though.

I've not measured the frontal area of any trailer, but if it's 8' wide and 8' tall that's 64 sf... now the grey wolf we bought has a very sloped front of the hard plastic material so it will be more slippery than most other designs.

[Herk7769]

This article regards how drag is computed based on shape, speed, and area presented to the wind. It is pretty complete but the example is F-16 external stores (which vary from sleek fuel tanks to "dirty" munition shapes).

**************************************************

Drag index of a store is a shorthand way of estimating the drag of a store at a typical cruise mach number. The basic airplane has a drag index, and each piece of added equipment (pylons, tanks, bombs, pods, etc) had a drag index. When all the drag indexes (indicies??) are added, the complete configuration drag index is found.

The drag on a body is drag coefficient x dynamic pressure x reference area, or D = Cd x q X S. To get the total configuration drag, you could look up the Cd for each item (store, pylon, pod, basic airplane), look up the reference area for each item, calculate the drag on each item, than add all the drags together. A simpler way is to use the same reference area for all elements, add all the coefficients (drag indexes) together, and calculate the total drag.

There should be a list of store drag indexes somewhere in the stores TOs, but if you can't find it or if the store isn't listed, all is not lost.

A drag index for a clean F-16 is the drag coefficient at 0.8 mach using the reference area of the F-16 (300 sq. ft.). So what is a drag coefficient? Using a clean F-16 as an example, say the drag at 0.8 mach, sea level, is 8000 pounds.

D = Cd x q x S

so Cd = D / qS

D = 8000 lb
q at .8 sea level is 947 lb/ sq ft
S = 300 sq ft

so Cd = 0.0282

The basic airplane drag index would be 282, because it is more convenient to use whole numbers instead of all those decimal places.

To calculate a drag index for a store, first you have to find its drag coefficient based on it's cross section area. That information (Cd) may be difficult to find, but the manufacturer should be able to give it to you. If that fails, then use 0.15 for pointy store (Mk-82) or .20 for a blunt store (AGM-65) as a good estimate for Cd. Then calculate the Cd based on the F-16 reference area, 300 sq ft.

Cd (F-16 ref area) = Cd x (store cross section area / 300 sq ft). This value, after removing the 4 decimal places, is the store drag index.

Another way to estimate a store drag index is to find another store of similar shape, and use its drag index multiplied by the ratio of the store cross section areas. For example a Mk-84 and a Mk-82 have similar shapes. If you know the -84 drag index, (DI-84), you can estimate the DI-82 :

DI(82) = DI(84) x Area (82) / Area (84)

I apologize if I've gone into more detail than you wanted.

*************************

So if you made it this far; drag must be overcome with engine power delivered to the drive wheels, so fuel economy and towing performance is based on:

Pointy is good; blunt is bad
Slow is good; fast is bad
Smaller cross section is good; tall and wide is bad