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Jul 11, 2015 | 10:46 AM

gustrider4

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bigger tires

I have a 2015 f350 xlt with 18 inch rims, 33 inch tire. I want to get 35s sitting on 20 inch rims, can a ford dealership recalibrate the speedo.

Jul 11, 2015 | 12:02 PM

brd7666

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From: Clearwater Fl.

Quote:

Originally Posted by gustrider4

I have a 2015 f350 xlt with 18 inch rims, 33 inch tire. I want to get 35s sitting on 20 inch rims, can a ford dealership recalibrate the speedo.

The truck has three different settings, but the dealer has to set it for you. It's about 50 bucks. I just called my local dealer, and that is what I was told.

Jul 11, 2015 | 03:48 PM

RumpityRump

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From: Hawthorne,Ca.

My local dealer from whom I purchased my $50k+ F350 from said "NO".
What an a**hole....

Jul 11, 2015 | 05:29 PM

jtruck618

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I bought a programmer for my Wrangled that adjusted the speed. It was a 2012. Nothing exists for Ford vehicles?

Jul 11, 2015 | 06:02 PM

fordman19762003

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the stock 20" tires ford offers is around 34" so just have them calibrate the speedo for that size and it'll probably be close enough that it won't cause any problems. If they ask any questions just say you bought a set of take off 20" tires/wheels.

Jul 12, 2015 | 08:20 PM

Wizness

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From: Houston

Most people me included have there speedo run fast with 18s. With the 35s its usually right on.

Jul 13, 2015 | 02:33 PM

6.2 V8 power

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if you don't set the tire size on newer trucks the computer will go crazy. Its not just the speedo thats effected. its also the air/fuel mixture and the traction control. It all has to match the signal's sent from sensors for RPM wheel speed and transmission gearing. Dont know why a dealer wouldnt set the computer for you. Could it be that he wants to sell you some 20's

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Jul 13, 2015 | 05:40 PM

jtruck618

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I checked mine today and it is 1-2 mph slow at about 60. Still on stock,275/70r18.

Jul 18, 2015 | 10:29 PM

#10

gustrider4

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funny, my gps says i am going 65, truck says im going 68ish

Jul 19, 2015 | 06:40 AM

#11

NYCruiser

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From: Yonkers, NY

Speedo's are never going be exact from the factory. Its a trade off because a tire can lose an inch or more sometimes as tread wears, so they set it around a mid point to limit the variance. It'll typically read slightly low on new tires, and slightly high on old tires.