CAT Scale results 2009 F150 Supercrew 2X4 and 1997 34" Excella

[Aviator]

2Air would be proud of me. I stopped by the CAT scales today and weighed the rig. I am towing a 1997 34' Excella with a 2009 F150 Supercrew 5.4L gas engine and 2X4 drivetrain. Max weights; Front Axle 3600#, Rear Axle 4000#, GVWR 7100# Wheel Base 145" Max Tow 11,300# GCWR 17,100#

Following are the scale results:

Truck only, no "stinger" for 3P hitch, full fuel, driver (185#), 11 yr old son in rear seat (90#) wife and 10yr old daughter missing. (but I know they are around somewhere)

Front Axle 3280# Rear Axle 2740# Gross 6020#

Truck & 34' Airstream, 3P Hitch Bar stringer set to 4th hole from top of 6, empty holding tanks (we have yet to travel with them filled)

5" weight distribution jack extension
Front Axle 3160# Rear Axle 3700# Trailer Axle 7620# Gross Wt 14480#

6 1/2" Weight distribution jack extension
Front Axle 3320# Rear Axle 3520# Trailer 7640# Gross Weight 14480#

7 3/4" weight distribution jack extension
Front Axle 3380# Rear Axle 3460# Trailer 7660# Gross Weight 14,500#

I find it interesting that moving the weight distribution jacks beyond 5" actually moves a little (20#) back to the trailer axles. The tongue weight appears to remain steady at 820# with the increased jack extension.

I will probably run at the 6 1/2" jack height as it gives me a bit more buffer on the front axle (remember my wife, daughter, and dog weren't in the truck for the weigh in). Generally we carry very little additional weight on the truck bed, and most of the additional stuff in the trailer is food and clothing which all goes on or aft of the axles.

Thank you to all of the Airforum folks who did this before me so that I would know to do it. It provides peace of mind, plus allowed me to better adjust my 3P hitch for a safer towing experience. It also tells me that should we ever consider full timing (many years from now when the children are off to College or beyond), a move to an F250 may be in order. I know FT people have a lot more stuff in the trailer and vehicle than weekenders and rally folks like ourselves.

I hope this helps anyone considering doing something similar.

[2airishuman]

nice post aviator!

the 6.5 inch does appear 2b the best starting place.

towing this way will confirm your choice.

the TINY (20#) shift aft was basically the same number i had...

in the early 'cat scale thread'...
_________

assuming the side2side loads are close to equal,

you got data now for tire inflation on the truck.

not sure if your truck came with 18s or 20s but inflation matters.

_________

the scale data also helps with respecting the carry capacity of the 34...

good stuff!

cheers
2air'

[Aviator]

The truck is running on Pirelli 275/55R20 tires inflated to 35psi with a max load of 2403# per tire. These are the factory stock tires the truck came equipped with.

Between the tongue weight of the trailer and my family, the tire load is my tightest limit. It would be a good idea to look at getting more capable tires for the next set.

Thanks for asking the question 2Air as I hadn't looked at the truck tires as closely as I should have!

[2airishuman]

Originally Posted by Aviator

The truck is running on Pirelli 275/55R20 tires inflated to 35psi with a max load of 2403# per tire...

ok, good info.

while ford recommends a 35 psi inflation,

that isn't while towing or under heavy bed payloads.

and the 2403 lb load rating is AT the max psi which is probably 44 psi (cold inflation) stamped on the side wall.

so while towing, consider bumping the trucks tires to at least 40 psi.

this will provide MORE of the available load capacity and

improve steering control without making the ride too firm.

and the extra volume of air inside the tires will reduce heat, protect the rims and improve brake performance.

((not that u asked for tire advice))

cheers
2air'

[Aviator]

Thanks, 2Air. I will go plug in the air compressor since we head up to Top of Georgia tomorrow.

[mddsmith]

Originally Posted by 2airishuman

while ford recommends a 35 psi inflation,

that isn't while towing or under heavy bed payloads.

and the 2403 lb load rating is AT the max psi which is probably 44 psi (cold inflation) stamped on the side wall.

so while towing, consider bumping the trucks tires to at least 40 psi.

2air'

2air, I'm glad you brought this up. Even though Aviator didn't ask for tire advice, I'd like to, if I may. I have always kept the tires on my F-150 just below the 35 psi recommended by Ford and the tire manufacturer. I've done this when towing and also when just driving around normally. Now I've bought a new set of Michelins, and they have 44 psi max inflation stamped on the sidewall. I don't recall ever having a set of tires with a maximum inflation that is different from the vehicle manufacturer's recommended inflation, and I've been unsure what pressure to keep in them. What you said to Aviator makes sense, but when NOT towing, should I keep it up near the 44 psi max? I've tried this and sure can feel that the ride is firmer. Am I shortening the life of the tires or risking damage if I keep them at 35? I've compromised thus far and have been keeping them at about 38-40. Any guidance will be apppreciated.

[mello mike]

I keep my tires inflated to 40 PSI at all times. BTW, that's what the tires were inflated to when I first picked it up at the Ford Dealership.

[2airishuman]

Originally Posted by mddsmith

... I've compromised thus far and have been keeping them at about 38-40. Any guidance will be apppreciated.

hi mike

KEEPING with aviator's thread theme...

so as to not HIJACK it...

have u weighed the truck?

have u weighed the truck/stream combo?
________

notice the FIRST weight measurement posted above by craig...

front=3280, rear=2740.

this is TYPICAL for trucks (a front weight bias) without much IN the bed.

his MIDDLE set up takes the truck to...

front=3320 and rear=3520...

so while keeping the STEERING axle ~at the unhitched value, the DRIVE axle has gained 800 lbs.

that loading CAN benefit from more air in the tires.
_________

now, IF your new tires are "oem" sized and "oem capacity" it's hard to argue with the 35 psi posted ON the door/B pillar.

UNLESS your truck has a shell and much GEAR regularly on board to INCREASE the weight.

so the best advice is get a WEIGH IN at least once for the truck.

then u could tweak tire pressures as needed.
__________

yes the wear pattern MIGHT change if the tires are NEAR THE MAX psi without adequate loads...

but a few extra psi, for example 39 front, 37 rear... improves mpg a tad.

and IF they are lower profile tires (55 series or thinner) the extra air protects the rims from pot holes...

i happen to LIKE a firmer ride *(my buttometer has been tweaked by german cars) for most driving.

and rely on axle loads for adjusting cold inflation on the truck.
__________

cheers
2air'

[Aviator]

FWIW, CAT Scales are .......CHEAP!!! The cost was $9 for my first pass, and only $1 for the next three passes. At the risk of doing public math, that makes $12 to weigh and adjust my rig. I have had three previous camping outings with my truck/trailer. The first two were with a Reese set up (It will shortly be listed for sale), and the third with my 3P setup. On the initial 3P outing, I now know that it wasn't properly adjusted. There was way too much weight on the hitch. It still towed far better than the Reese, but I am really looking forward to going up into the North Georgia mountains tomorrow with a properly adjusted hitch! $12 is a very small price to pay for that assurance/confidence in my equipment.

[mddsmith]

Thanks, both of you, for the info. No, I haven't weighed yet, and I had wondered how much it was going to cost. I will do it before the next trip, though!

[mddsmith]

Originally Posted by mddsmith

Thanks, both of you, for the info.

And thanks to you too, mello mike. Didn't mean to leave you out!

[mello mike]

CAT Scales website....CAT Scale

Has a nice locator feature.