View Poll Results: I have a 2011 with oversize tires and...
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2011 F150 larger tire programming at the dealer
09-27-2011, 09:14 PM
#21
re-calibrate for larger tires
When I picked up my new 2011xlt sc 4x4 it had P235-75-17's, hankooks. I did my own dealer trade on it,wanting to be the first to drive the truck home,about a 250 mi trip. The p235 tires looked really small and I had already decided to trade them for 265-75-17 Michelins. After I had the tires changed out I noticed right away that the indicated mph and miles traveled were off. I could live with 1-2 mph indicated speed difference but since true milage traveled would also be off,I took my truck to my Ford dealer and had it calibrated. Service manager told me that one size larger than what I put on the truck was the last size they could calibrate.
Before I changed tires,my in town mpg was at 17.3,-highway 21.3.After changing tires and before re-calibration,in town was 15.7,highway 18.8.Things are now back to normal,17+ in town,21.1 highway.
I did verify milage and speed with a gps.
Before I changed tires,my in town mpg was at 17.3,-highway 21.3.After changing tires and before re-calibration,in town was 15.7,highway 18.8.Things are now back to normal,17+ in town,21.1 highway.
I did verify milage and speed with a gps.
09-27-2011, 09:22 PM
#22
Senior Member
Thread Starter
It previously was possible for dealers to program in larger tire sizes...
But is the capability still there on 2011's.
09-27-2011, 09:28 PM
#23
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Originally Posted by pfbz
And this is on a 2011??
09-27-2011, 10:29 PM
#24
Senior Member
Thread Starter
There is so many tire sizes in a ford tire database. You may be able to program sizes but if they are real good you can change parameters on a metric scale and enter just about any size by imputing the over all diameter of the tire size. Talk to the service advisor and they will ask one of the high tech technicians to check there tire calibration settings. They can do it guaranteed. There are just too lazy to check.hope that helps.
Do you have any specific knowledge that this capability still exists on the latest rev of the IDS system??
09-27-2011, 10:45 PM
#25
Senior Member
Thread Starter
So lots of people are saying yes, sure, it can be done, but no verification.
So far only one person (pappamike) has said:
If the dealer changed the programming in his truck to the factory tire size of 275/6518, it would be extremely close to his new tire size, only 1.8% error. 55 mph on a gps would be shown as a hair above 54 mph on the speedo. I don't think it's possible to even read the speedo within 1 mph.
I'd really love the answer to be yes, dealers can do it if they know how, but so far we don't have a single owner (or active Ford technician) who can verify this...
So far only one person (pappamike) has said:
- I have a 2011.
- I put on larger diameter tires.
- I had the dealer reprogram my tire size.
- I verified that the speedo is correct.
If the dealer changed the programming in his truck to the factory tire size of 275/6518, it would be extremely close to his new tire size, only 1.8% error. 55 mph on a gps would be shown as a hair above 54 mph on the speedo. I don't think it's possible to even read the speedo within 1 mph.
I'd really love the answer to be yes, dealers can do it if they know how, but so far we don't have a single owner (or active Ford technician) who can verify this...
Last edited by pfbz; 09-27-2011 at 10:48 PM.
09-27-2011, 11:17 PM
#26
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Originally Posted by pfbz
So lots of people are saying yes, sure, it can be done, but no verification.
So far only one person (pappamike) has said:
[*]I have a 2011.[*]I put on larger diameter tires.[*]I had the dealer reprogram my tire size.[*]I verified that the speedo is correct.
But the problem with this example is that while he upgraded the tire size from what came on his truck, (235/75R17's, 30.9") to 265/75R17's at 32.6", his new tire size is *very* close in diameter to another stock F150 size: 275/65R18's (32.1").
If the dealer changed the programming in his truck to the factory tire size of 275/6518, it would be extremely close to his new tire size, only 1.8% error. 55 mph on a gps would be shown as a hair above 54 mph on the speedo. I don't think it's possible to even read the speedo within 1 mph.
I'd really love the answer to be yes, dealers can do it if they know how, but so far we don't have a single owner (or active Ford technician) who can verify this...
So far only one person (pappamike) has said:
[*]I have a 2011.[*]I put on larger diameter tires.[*]I had the dealer reprogram my tire size.[*]I verified that the speedo is correct.
But the problem with this example is that while he upgraded the tire size from what came on his truck, (235/75R17's, 30.9") to 265/75R17's at 32.6", his new tire size is *very* close in diameter to another stock F150 size: 275/65R18's (32.1").
If the dealer changed the programming in his truck to the factory tire size of 275/6518, it would be extremely close to his new tire size, only 1.8% error. 55 mph on a gps would be shown as a hair above 54 mph on the speedo. I don't think it's possible to even read the speedo within 1 mph.
I'd really love the answer to be yes, dealers can do it if they know how, but so far we don't have a single owner (or active Ford technician) who can verify this...
09-27-2011, 11:19 PM
#27
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Originally Posted by 4wdmike
That 17" tire size is the most difficult to work with. I deal with it all day long. Your tire guy is correct. There is not an exact mate to the 235/75r17. I too think it's either 285/65r18 or even the 285/60r18. But having said that the 1.8% difference is not too bad. Have them trying to input the actual measurement of another tire manufacturer like bridgestone or firestone or any manufacturer that makes any tire with the OD that matches your original amount of 30.9. For example if firestone makes a 255/75/18 and it's OD is 30.9" then manually enter that size in because the OD of the tires are the same and the PCM will like that. It doesn't matter what the real tire size entered is only if the OD matches. Hope that helps.
09-28-2011, 12:02 PM
#30
Senior Member
IDS only allows you to enter a select few tire sizes that ford offers as acceptable. Thats it cut and dry. If anyone else says anything different they are wrong.
It is all about diameter. If IDS doesnt have your tire size we have to use a smaller rim diameter with a larger tire diameter to get it close. You can not put in revs per mile with IDS.
2 mph is a big deal in these electronically controlled transmissions. Your shift points and drive ability go out the window affecting mpgs. If the trans is not shifting as efficient as it is supposed to on the correct parameters you lose performance, mpg and over driveability. If you want it perfect get an aftermarket tuner. For the Ford trucks your top 2 are the SCT SF3 or the Edge/Gryphon
It is all about diameter. If IDS doesnt have your tire size we have to use a smaller rim diameter with a larger tire diameter to get it close. You can not put in revs per mile with IDS.
2 mph is a big deal in these electronically controlled transmissions. Your shift points and drive ability go out the window affecting mpgs. If the trans is not shifting as efficient as it is supposed to on the correct parameters you lose performance, mpg and over driveability. If you want it perfect get an aftermarket tuner. For the Ford trucks your top 2 are the SCT SF3 or the Edge/Gryphon