reason903

My brother has an (2006) F250 and recently found someone selling brand new (2014) 20 IN FORD OEM rims and tires for the same cost as new tires so he grabbed them. When we went to tow our boat (30Ft) this weekend the F250 was all over the road, unlike ever before. The only thing that has changed is the RIMS and tires and the are FORD OEM. They look allot better as the rim fills the wheel well, but why would they affect towing performance?


I just ordered a new F150 with Max Tow Package so I can pull the boat when his truck is not available. I spent the extra money for the 20 in rims as well as I personally think it looks better, not for bling as some state on the forum, but because the tire fills the wheel well. Did I make a mistake? Will the 18 in tires and rims give me better towing performance?

brulaz

If those were F150 tires/rims, he made a mistake.
EDIT: Of course they could not be F150 rims cause they are 6 not 8 lug.

An F250 would have LT-E rated tires (LT=Light Truck, E is the weight rating) not the P rated tires (P=Passenger) that normally come on an F150.

Think he should get LT-E Tires that match his weight ratings. They will be stiffer and better for towing than the P tires.

Also, F150 rims would not be rated to carry the weight that an F250 can.

As for your F150, many of us have switched to LT-E or -C tires as well, but some are fine with just pressuring up the P tires to their max as specified on the side wall.

reason903

Sorry no his new tires and rims were off a brand new f250. Cant figure out why the truck would tow so differently with the new rims and tires. So you think I will not notice much difference in towing with 20's vs 18's?

brulaz

Well it is odd then.

20" will have less side wall than an 18", but I can't imagine that difference having a huge impact. If anything, less side wall should mean less squirm and tighter handling. Not worse.

On the down side though, when tow/hauling heavy you have less side wall when hitting potholes and road debris. But that's nothing to do with handling.

Perhaps there was some other difference in the tires, tread design or composition? What about tire pressure? Was that checked?

acadianbob

Was it also a switch from LT tires to P metric tires?

reason903

Thinking maybe the tires are so new that they need to harden up a little? New tires are off a king ranch F250 so they are E rated tires. Old tire size 285/70R17 new tires 275/65R20, so there is not much difference, a little wider on the old, but before those his stock were 275 and we did not have the sway. Anyone have experience in tires needing break in, new ones are only 3 weeks old.

uzikaduzi

i think it's likely something actually wrong.... a bent rim, broken belt in the tire, low air pressure,... i doubt this is possible since they are oem rims, but the wrong size hub bore. it could be a loading issue i guess... maybe the boat isn't as far forward on the trailer or the axle got bumped out of square? i don't think it's the rim size or the tire being too new.

acadianbob

I agree. I'd be very surprised if this is a tire issue.

PerryB

If the tire has a tall blocky tread it will squirm until they wear down some. The condition is known as tread squirm and is common with aggressive tread patterns. It may be barely noticeable empty but will become obvious when towing heavy. Several years ago I put the most aggressive tires (dual) on the back of my f450 tow truck I could get to improve its mud capability. The truck became almost unmanageable with a big load on the lift. It IS a tire issue.

dusty_ranger

the tire profile will also affect wandering while loaded, especially if the road is rutted
had a 08 dodge 5500 wrecker that wanndered pretty wild 19.5 rims and lowish profile tires