Tires size & towing

[tkkz71]

I just purchased a used 2022 RST. It has 5.3 10spd trans 3.23 gear with 13,000 miles on it. According to the window sticker, the truck originally came with 18 inch wheels. Someone put the 20” black rims with Toyo Open Country A/T3 P295/55R20  tires on it. My question is this, how much will these tires have an effect on mpg and performance both normal driving and towing? (My truck does not have DFM from the factory) 

[newdude]

Yes.  Spinning more weight, wider contact patch and your speedo is probably off unless the PO used something to correct it.  About 2mph off.  

Edited November 30, 2024 by newdude

[tkkz71]

51 minutes ago, newdude said:

Yes.  Spinning more weight, wider contact patch and your speedo is probably off unless the PO used something to correct it.  About 2mph off.  

Thank you for response 

[CamGTP]

If the load rating on the tire is the same as a stock size, you can tow pretty much the same amount.

 

Expect fuel mileage to drop atleast 2mpg in my eyes because not only are the 20in rims heavier, the bigger tires are too. I bet each corner is now 30-40lbs heavier. And the wider tires will make towing a little worse because the contact patch is so much wider that it can grab more of the road and push you around when it follows cracks etc etc.

[Polo08816]

23 hours ago, CamGTP said:

If the load rating on the tire is the same as a stock size, you can tow pretty much the same amount.

 

Expect fuel mileage to drop atleast 2mpg in my eyes because not only are the 20in rims heavier, the bigger tires are too. I bet each corner is now 30-40lbs heavier. And the wider tires will make towing a little worse because the contact patch is so much wider that it can grab more of the road and push you around when it follows cracks etc etc.

 

20" wheels and highway all season 275/60/20 tires are a bit heavier but not by that much that you would get 1-2 mpg worse.

 

You usually hear about significant fuel economy impacts because someone's going with a significantly larger wheel/tire setup compared to factory along with AT or MT tread patterns which are not fuel efficient.

 

There was a thread on the F150 forums where someone mounted a slightly larger Load Range E tire 275/65/20 and compared the fuel economy to the factory setup and it's really not that much different:

 

https://www.f150gen14.com/forum/threads/apples-to-apples-efficiency-comparison-factory-33s-vs-lt-34s-tires-fixed-course.19977/#post-386490

[CamGTP]

I can understand what you said but with the OP in this thread we are talking about going from a 265/65/18 to a 295/55/20. That is a huge jump in size and weight and where the mpg hit is going to come from.

[swathdiver]

Every pound of rotational weight is like adding 8.4 pounds to your payload.  

 

A stock wheel weighs about 30-35 pounds and the P265-65-18s weigh about 38-40 pounds each.