Tire size for factory 20s on a stock '06 350 - Diesel Forum

Faceplant409 · 10-24-2007, 01:43 PM

I finally got my hands on a set of 20" Ford take offs and now I need tires. Truck is a stock '06 F350 CC Lariat with the camper pkg.
I'd like to run BFG AT 285/65R20s (34.7 X 11.5) but I don't know...
My 18" Contis are 32.1 X 10.9. Will I NEED a leveling kit to run a 34.7" tire? I never saw the 20" stock goodyears (close up)on another truck so I can't gauge how much I have to play with...

Thanks!
Pat

HeavyAssault · 10-24-2007, 03:18 PM

Those tires should work without any issues. The OEM tires were Goodyear AT/S LT275/65R20 if I remember right.

ABFord · 10-24-2007, 07:30 PM

Those tires should fit not a problem. The OEM tires are a 275/65R20. Myself I am running a 325/60R20 on the stock 20's with no rub, mind you I do have the front leveled. Those 285's will look good for sure.

Faceplant409 · 10-25-2007, 03:39 AM

Did the 20" wheel tricks come with lower gears???

SteveIn29 · 10-25-2007, 11:43 PM

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Faceplant409</div><div class="ubbcode-body">Did the 20" wheel tricks come with lower gears??? </div></div>Nope, only gears for a diesel truck were 3.73 no matter what tire size was on it.

dieselwhisperer · 10-25-2007, 11:58 PM

While we're on this subject, I also have got a set of 20" take offs coming for my 08 F250. My truck has the cheap-o chrome 17" wheels on it right now. Here's my question, I know my speedo is going to be off but how much and in which direction? The way I'm thinking, the larger tire will travel more distance per revolution than the smaller tire, so will I be actually going faster that my speedo says or slower? Also, you would think that the miles on the odometer would show less miles than you actually go.

Faceplant409 · 10-26-2007, 02:36 AM

I think the miles would be recorded incorrectly. From what I have gathered...... the stock tires on the Goodyears were like 601 revs/mile. The 18" contis were 653 rpm and the BFG 285/65/20s are 599 rpm. Apparently the dealer can only adjust to the largest tire offered from the factory (20" Goodyears @ 601 r.p.mile. So the speedo can be close if you have the dealer do it.... but not spot on.

There are other ways of adjusting, I'm just not interested in them.
Patrick