Hello, I'm a newbie but bear with me. I have a 2000 F-150 supercab Lariat. For some reason, it came with 275 60 R17 tires. I guess the 17 inch tires were a factory option because that is what is listed on the driver's side door plate as tire size. My question is would it tow better with 16's on it? Also, how would that affect the gas mileage and would I have to calibrate the speedo if I switch. I'm getting ready to buy a travel trailer and want the biggest I can tow with this. It has the 3.55 LS rear end and the 5.4 of course. I know I will get the WD hitch and sway bars. Should I get air bags to? Any help would be greatly appreciated.

 

You won't gain anything by using smaller rims. Well, maybe a theoretical 500 pounds, but I doubt it. Keep the UVW or dry wieght rating under 5000 pounds and you'll be fine. You're talking about towing with a 10 year old vehicle. That last thing you need to worry about it the MFR ratings when it was new.

 

With a WD hitch adjusted correctly, air bags are a waste. You're not talking about a monster trailer where lots of extra would help... are you?

 

Thanks for the reply. I have read some posts that claim the smaller tires will transfer more torque to the ground kind of like changing the gear ratio in the rear end to 3.73 or something. That is what I am refering to not so much the weight gain.
The trailer I'm looking at is about 5500 lbs UVW so I know I will be pushing it. It is an older vehicle but only has 57,000 on it. I bought it from the original owners at 43,000 mile 2 years ago. Well maintained truck. Not a scratch or ding on it.

 

Thanks for your reply also. The trailer I want is 5500 UVW And I just got some good news last night. My step-dad has a draw tite WD and sway bar set up that he is going to give me. I though he sold it when he switched to a motor home a few years ago but he said he kept the hitch when he traded in the trailer. I guess i won't bother with the bags then.

 

The wheel size doesn't make a difference.
It's the overall outside diameter of the tire that makes the difference.

A smaller outside-diameter tire will lower your gear ratio, just as a larger diameter will raise it.

 

Ok,does that mean a 16 will raise the ratio since it is smaller than a 17? And when you raise the ratio, you increase the torque to the ground? I don't know that much about this but I do know that 16 inch tires are much cheaper to.

 

When he says the wheel size, he means the actual metal rim. With the OEM 17 inch wheels, mine came with 265/70/r17's For my winter tires, I use 265/75/r16's which have the same outside diameter. There is no gear ratio change at all, the revs per mile are identical, therefore no net effect on towing. I believe that the OEM tire size for 16" wheels is 265/75/r16's for 4x4's, which again, would make no difference.

 

And the trailer that you want 5500 UVW? You are talking 7500 to 8000 by the time you are ready to leave the drive way. I would look at something that is 5500 with all your stuff. I have a 21 foot that is 4900 uvw, And with the quad's, water and all the other stuff we take it's a little too much.

 

1. Depends on the tire you put on it. Go here:
http://www.1010tires.com/TireSizeCalculator.asp
...to see the diameter of the tires/wheels you are considering.

You need to make sure that you calibrate your speedometer to take a different-sized tire into account.

2. Yes. You can also do this with gears, especially with stock tire sizes, as you don't want to put tiny tires on your truck. And to make a big difference, you're looking at some significantly smaller tires. Gears may be cheaper than wheels/tires. What gear ratio do you have now?

Many guys run 4.10s with stock-sized tire, and they work great for towing and all-around power.
I have yet to read one negative post about this swap with stock-sized tires. Lower gears increases torque to the rear wheels.

I've got a supercharger but my 4.10 gears (on 285/60R18 tires) still make a big improvement in towing power.