Tire size question
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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
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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.
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New User
Joined: Mar 2005
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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
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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
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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
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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.
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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.
