A note in the F150 brochure states that towing capacity is reduced by 500 pounds with 18" tires. Anyone know the reason?

Thanks

 

cheepo OEM tires are rated low.

 

The reason is due to the reduced gearing with the larger tires. The larger the diameter, the lower (numerically) the effective gear ratio, hence the lower tow rating.

I don't think tire quality has anything to do with it in this case as I'm sure the 18" Good Years are better than the 17" Generals.

 

I was under the impression that there is a difference in the height of the tire packages, which changes the effective gear ratio thus reducing the amount the truck can pull.

Dodge downgrades their 1/2 ton by 1000 pounds when you order 20 inch wheel vs the standard 17s.

 

actually it is due to rolling mass the tires and wheels a calculated into the how much brake effort it takes to stop the the truck under every possiblity, thus when you increase tire and wheel size you increase wieght and the amount of force it takes to stop the vehicle with out experincing brake fade (brakes overheating) thats why dodge and their 20's have to take away more weight from the tow capicity.

tire size and gear ratios do affect tow capibility abut only when changing gear ratios, thats why there is a differnce in tow capcities between the 3:55's and 3:73"s both offered in the 04-05 F150's

ie. a FX4 supercab 5.4L 3v 144.5wb 3:55 is 8300 same truck with 3:73 is 9300 less the 500 if you have 18" wheels. gcwr with the truck above with 3:55's is 14000lbs the 3:73 15000lbs


is you follow this link http://www.fordvehicles.com/trucks/f...section=MODELS at the bottom right there is another link for a very good interative towing guide.

Mac.

 

Sweet post!

 

Thnx

Mac.

 

OK, Enough debait, The 17 inch 255-65 michelin on a cast STX wheel weighs 58lbs.
Somebody weigh an 18 incher.
Hopefully a 265-60-18 with a Long Trail.


Actually I really want to know this, without pulling a tire off of my truck. Hopeing someone will have a spare, or take off laying in their garage and will weigh it.

Thanks
Chris

 

Ok, I have a full set of the 18" OEM FX4 wheels with BFG ruggedtrails in the garage I took off since mine was new and I couldnt resist digging one out and weighing it.

Weighs in at a full 72 lbs. including center cap

seems Mac is rite! :santa:

 

But that includes 35lbs of air........

 

Thanks yob2kanobe;
Ouch that's a lot.
14 lbs, less whatever the heck the cap weighs. figure 13 lbs differance, or about twenty percent heavier. Not trivial.

Did your FX4 come with the same dual spoke rims as the lariat?

Just wondering if there is a differance in wheels. Lots of different styles on these trucks.

Chris

 

Whoops, What size are your tires? I'm messing with 265-60-18. Lots of differance between that and a 275 etc.
Thanks
Chris

 

Mine are the stock OEM 275/65R18
FX4 option

 

Thanks again yob2kanobe, Nice looking rims, altho not as nice as the ones now on your truck.

These are the rugged trail 275's which I think are a bit heavier than the 265 long trails.

I wonder if that rim is heavier? no split down the middle like my lariet wheels.

Still hoping someone has the 265-60-18 on Lairet's to weigh.


Sure is a heck of a spread in weight on these tire/rim combos.
Chris

 

can u can imagen how much those 20's, and bigger weigh in at.

Mac.