I have an 04 F150 XL 4x4 with the 3V 5.4 and automatic transmission. I am going to upgrade my tires from a 255/70R17 to a 285/70R17, and I called the dealership about recalibrating the speedo. They said they couldn't, but gave a shop's number. When I called, the guy said he couldn't do it, only the dealership could. Also, (getting to the point now) he says by the way, "If you do that(put 33's on) you are going to kill your gas mileage, and your motor and transmission too." He went on to say I would lose 4-5 mpg, and that the newer trucks just aren't built to "push around those big heavy tires." Is this guy serious, or is he full of it? I really thought that 33's was a fairly mild increase seeing as many come stock with 265/70R17's.

 

thats bs- my stock tires were 32's, ive got 33's on now and the dealership recalibrated the speedo for $30- sure if you put muds on like me, you'll see some mpg loss, but give me a break, if the truck cant handle bigger tires, hows it even gonna work under load... find a new dealer if they wont touch it- it takes about 30 mins to do it... find out the revs per mile on your larger tire (usually on manufacturer's website for that tire)- tell it to the tech at ford, and go sit.
justin

 

If the vehicle is "built tough" and can tow over 9000 pounds. I don't think that some 70 pound(each) tires are going to do much to it. it may change your shift points and mph if you don't recalibrate and yes they will decrease your mileage a bit, but will improve traction and lift your truck some. I have had 33's for about 6000 miles no problems. i like them and the truck runs fine in my opinion.

 

Kill may be an overstatement, but larger and heavier tires will affect mileage, acceleration, braking, and increase wear on suspension components. It will probably ride rougher too. By how much depends on your driving style.

I bought 285/70R17 BFG AT KO's with 250 miles on my Supercrew. This truck gets about 2mpg less than my previous truck with equal weight and drivetrain. After 34k miles, the tires look great and will proably last another 34k, but I can't wait to get them off.

70 pounds of rotational weight at each wheel compared to stock tires of about 40 pounds is a huge difference to the drivetrain. 120 pounds extra in the bed of the truck is quite different. 33's are typically 55 poundea, not 70 though.

 

Yep, you recieved some misinformation.
Also, the dealer can only reprogram your speedo to an OEM tire size (I believe). The dealer could program your computer for the largest tire size available (a 275/65-18 from the FX-4 I believe) which is only slightly shorter than the 285/70-17's. This would get your speedo/odometer very close.

 

Thanks for your help. The tires are actually Goodyear Wrangler MT/R's, and list at 57 pounds each. The factory tires on the truck list at 39 pounds, but the Fx4 has optional 275/65R18 Wrangler AT/S at 49 pounds. The gas mileage is not a huge issue to me, if I wanted 40 mpg I would have bought some honda or something. I live in a fairly small town with only the one dealership, and the next town over also said no. That's ok, ill just have to get a tuner and some extra horse power, and maybe even offset the mileage loss a little. I just thought it was strange coming from a shop advertising itself as a Ford specialist with over 30 years experience.

 

Wait a minute!The gas milage won't hardly change.I got an 06 4.2ltr V6 Automatic, I put 33" on mine.I probably lost 1/2 mpg and that ain't from the weight of the tires,it's from the weight of my foot.Speedo is off and I like cruising@ 70mph on the speedo that's 78.82 calculated mph.I'm get'in 17mpg.And when the xcalII comes in that will straighten the speedometer up.
Also ford can do it,but some dealerships don't want the computer tech.to search the system for a fix.At my local dealership they said 40 bucks for the tech to hook up the computer to tell me how large a tire I can calibrate to.Then bring it in and pay another 40 to do it after the install.I put the 80 bucks in tires and the xcalII.
https://www.f150online.com/galleries....cfm?num=10586
The tires are here.
I won't dispute anyone elses comments this is my experience.But I have to say 1 thing,you can get 2 trucks off the same assembly line and they won't be exactly identical as far as performance,wear & tear of parts,mpg,it just can't be done.
.Later

 

if you were putting on alaskan husky 55's it would be one thing,, but not 32's

 

BalogUK your truck looks awesome with those tires. the exhaust also sounded really good when i was walkin to class this morning. Montana rocks.

 

hey someone else is in bozeman!? thanks for the compliments- yea i love both the tires, and the roush exhaust- its my friend so uh, where do you see my truck?? im still taking advantage of my 'handicap' status, so im parked infront of north hedges when im over at the architecture building (cheever)
edit: just looked at your gallery ty- i thought i recognized your truck in the sig- dayton timberlines right? you're parked infront of all the construction- sometimes with a sled in back- right?? sweet setup you got there too

sweet
justin

 

It depends how your drive. My guess is that since you have a V6, it isn't that agressively.

 

Oh how those 2 extra holes in your block make you all the wiser!I'm to old to argue so I've decided to not comment any further on this issue.Sorry you must be correct.

 

My point is that since you purchased a V6, you must find the level of performance acceptable. It has nothing to do with one person being wiser or right and the other wrong. We both got what we wanted for the performance of our trucks. Larger/heavier wheels/tires affect performance, but if one does not reach the performance limits of their vehicles, he may not notice the effects.

 

i always see you truck in front of the apartments you live in and the other day was the first time i saw it on campus.
yea thats my silver truck with the sled in the back of it sometimes

 

I have ran 33s and now run 35s. No problems at all.

https://www.f150online.com/galleries....cfm?gnum=4955