Tire size question
Thread Starter
|
New User
Joined: Mar 2005
Posts: 20
Likes: 0
From: Waskom, TX
Tire size question
I have an 03 Super Duty, 6.0L truck that came with 235/85 R16 tires on it. It's about time to replace the tires, and I want to know how to fix the affect that different tires will have on indicated speed. I want to replace them with 245/70 R16 tires. This will throw the speedo off by about 4 mph. No problem if it's just me driving it, but that's not possible. Considering that Ford PUs can be ordered with several different tire sizes is it an easy thing to reprogram the computer for the different tires? Maybe this is something that the dealer can do?
Thanks
David Killeen
Thanks
David Killeen
FTE Leadership Emeritus
Joined: Jan 2003
Posts: 161,999
Likes: 75
From: 3rd Rock
...Welcome DKilleen, to Ford Truck Enthusiasts! Please read the Guidelines, it will help you to navigate through and understand this site.
Stick around someone will be by shortly to answer your question.
We are happy you have chosen the best source for Fords!
Enjoy FTE....and
JOIN CLUB FTE -SUPPORT THE FORUMS!
…..See you on the boards.
Stick around someone will be by shortly to answer your question.
We are happy you have chosen the best source for Fords!
Enjoy FTE....and
JOIN CLUB FTE -SUPPORT THE FORUMS!
…..See you on the boards.
Posting Guru
Joined: Nov 2002
Posts: 2,440
Likes: 0
From: Ventura County, CA
DKileen,
Ford can reset your truck's computer for the different size tire. It cost me $60 for Ford to do mine. Still not sure it's dead-on accurate, but it's pretty close and it beat the cost of a Tru-Speed speed calculator by a longshot!
And, uh...not that it's any of my business, but why are you going from a 32" tire to a 30" tire on a PSD? The 235/85X16 = 32X9.25X16. The 245/70X16= 30X9.65X16. So you're going to a shorter, lower profile, slightly wider tire ???Interesting...
Hope you don't mind me asking
DS
Ford can reset your truck's computer for the different size tire. It cost me $60 for Ford to do mine. Still not sure it's dead-on accurate, but it's pretty close and it beat the cost of a Tru-Speed speed calculator by a longshot!
And, uh...not that it's any of my business, but why are you going from a 32" tire to a 30" tire on a PSD? The 235/85X16 = 32X9.25X16. The 245/70X16= 30X9.65X16. So you're going to a shorter, lower profile, slightly wider tire ???Interesting...
Hope you don't mind me asking
DS
Last edited by DS02F250; Mar 24, 2005 at 09:39 PM.
Thread Starter
|
New User
Joined: Mar 2005
Posts: 20
Likes: 0
From: Waskom, TX
Originally Posted by DS02F250
DKileen,
Ford can reset your truck's computer for the different size tire. It cost me $60 for Ford to do mine. Still not sure it's dead-on accurate, but it's pretty close and it beat the cost of a Tru-Speed speed calculator by a longshot!
And, uh...not that it's any of my business, but why are you going from a 32" tire to a 30" tire on a PSD? The 235/85X16 = 32X9.25X16. The 245/70X16= 30X9.65X16. So you're going to a shorter, lower profile, slightly wider tire ???Interesting...
Hope you don't mind me asking
DS
Ford can reset your truck's computer for the different size tire. It cost me $60 for Ford to do mine. Still not sure it's dead-on accurate, but it's pretty close and it beat the cost of a Tru-Speed speed calculator by a longshot!
And, uh...not that it's any of my business, but why are you going from a 32" tire to a 30" tire on a PSD? The 235/85X16 = 32X9.25X16. The 245/70X16= 30X9.65X16. So you're going to a shorter, lower profile, slightly wider tire ???Interesting...
Hope you don't mind me asking
DS
But the tone of your post seems to point to a downside. Is there any reason why I'm better off with a narrow, higher tire? If so, I'll just go back with the stock size. Thanks
David
Posting Guru
Joined: Nov 2002
Posts: 2,440
Likes: 0
From: Ventura County, CA
David,
There's a bit of skepticism in my reply because my knee-jerk reaction when I saw the height that the 70 series tire equates to. The 30" height might disappoint you as it will look disproportionately small in the wheel well. You can get more rubber on the road and maintain (or even) improve the tire height, as you probably know. The 265/75X16 tire will give you more rubber on the road: 32X10.43X16 and you wouldn't have to have your truck's computer reset. Here's a link that converts tire sizes: http://www.dakota-truck.net/TIRECALC/tirecalc.html
I don't mean to come off rude or anything, and of course you should buy the tire that YOU want for your specific driving conditions and needs. But like I said, it just struck me as "different" for a SD owner to want to go to a shorter tire, that's all. Don't want you to have buyer's remorse!
Best,
Daryl
There's a bit of skepticism in my reply because my knee-jerk reaction when I saw the height that the 70 series tire equates to. The 30" height might disappoint you as it will look disproportionately small in the wheel well. You can get more rubber on the road and maintain (or even) improve the tire height, as you probably know. The 265/75X16 tire will give you more rubber on the road: 32X10.43X16 and you wouldn't have to have your truck's computer reset. Here's a link that converts tire sizes: http://www.dakota-truck.net/TIRECALC/tirecalc.html
I don't mean to come off rude or anything, and of course you should buy the tire that YOU want for your specific driving conditions and needs. But like I said, it just struck me as "different" for a SD owner to want to go to a shorter tire, that's all. Don't want you to have buyer's remorse!
Best,
Daryl
Trending Topics
Thread Starter
|
New User
Joined: Mar 2005
Posts: 20
Likes: 0
From: Waskom, TX
Thanks guys
. That was exactly the information I wanted. The 265/75 R16 will give me a wider profile without needing the speedo recalibrated. At 70MPH, that tire will indicate 70.2MPH. I can certainly live with that.
Cheers
David
. That was exactly the information I wanted. The 265/75 R16 will give me a wider profile without needing the speedo recalibrated. At 70MPH, that tire will indicate 70.2MPH. I can certainly live with that. Cheers
David
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
Senior User
Joined: Aug 2001
Posts: 389
Likes: 0
From: Georgia
If you have a GPS, I'd check your speedo first. Mine and several trucks I know, the speedo was reading fast from the factory. my truck was reading 3 MPH fast. when I went up to 285/70/16 now my speedo reads dead on with my GPS.
Junior User
Joined: Feb 2005
Posts: 53
Likes: 0
David, I just switched my 235/85/16's with 265/75/16's last week and I couldnt be happier. Both sizes are the same diameter (32") but the wider tread gives it a much nicer look. I also went from a E rated tire to a C because I am not hauling heavy loads and I only tow around 4k pounds. The ride is MUCH better. I dont feel like I'm on solid rubber tires anymore.
