jetjoe

I can't seem to find any good information about if and how to adjust the speedo after a tire change. I just installed the larger 275/65's and the speedo is about 4 mph off. I'm not anxious to give the local dealer $80 bucks if I can do it myself.


Some mention a wire to ground, then a procedure to adjust it manually but they're referenced to newer models. I can't find this wire in the diagrams or in the truck.


Any help would be appreciated.

ford4wd08

You'll need a programmer to change the tire size in an 04-08 F150.

VFL

Now is the perfect time for a tuner

jetjoe

Yeh! I sort of thought so but thanks for verifying that.


To "Gator941", I don't think a tuner is worth the money. I'm not one who believes I'm smarter than the Ford engineers. But, to each his own.

VFL

Ford engineers did not account for larger tires.

uzikaduzi

well you decided to put larger tires on it lol... honestly, even not for power, the transmission strategy improvements from something like an edge will lengthen the life of it because Ford needs to balance longevity and ride comfort

jetjoe

Yes I did put larger tires on. But that size was an option for that year and yes Ford did make the adjustment available. I did not and would not put such monstrosities on that make a truck look like something more suitable for an iron ore mining operation. That's not me. Actually I bought the rims to replace my scratched originals and the tires just happened to come with them. Exact same rims! They had plenty of life left on the Michelins so I just changed them out. The Michelins are so superior to the ride and sound of the BFG's that I would like to replace them with the same tire when the time comes. Hence the desire to adjust the speedo.


My question was "if I could do it myself" as was possible with other model years? My remark about me not knowing better than the engineers was just that. I know I am not smarter. No intended judgment of any others ability or preference for their vehicle.


After reading these blogs, I am starting to believe it is populated by younger folks who just can't leave a vehicle alone and have to change and putts with everything. Then whine like a baby when things go wrong. It's all Ford's fault! I too like to do my own work, but almost exclusively try to put things back the way the vehicle came. Or at least close to what the manufacturer originally intended and supplied. Being an elder by this site's standards I have come to learn that vehicles do just fine without me modifying. The last ten of them all went over 300,000 miles with no complaints. Yes I drive a lot.


With that thought, I wish readers and commenters would keep in mind some of us would like to use this site to find honest answers and experiences which do not necessarily match their everyone else's. And then, if appropriate, just pass on the comments that are pertinent and helpful. I could really care less what "the shift strategy of an Edge" might be. It certainly had nothing to do with my question. This sort of thing usually turns into a pissing match with everyone trying to do the other one better with the insults.


In the future I think I will seek advice elsewhere. No need to rely or comment! I know the answer to the question I asked.

Summers22

iTrader: (2)

I am not a "younger" person at 42 yo, but if it were me, take it to Ford and have the PCM reflashed for the new size. As you know, you cant do it yourself.

**Side note, this is the internet, some answers won't satisfy your question. Either get worked up about it, or ignore it. Such is life.

uzikaduzi

Quite a bit of judgement and assumptions there sir... i did not mean my comment to be anything other than a joke about a comment that you made that could has as easily been taken as some sort of insult (but i assume you meant it as a funny way to explain your opinion on the matter) this is more of a community than simply a technical forum. there is certainly a vast amount of knowledge here but you cannot honestly expect people to not give their opinions on an open forum when you are also going to give yours.

In addition to my attempt at humor i was adding the comment about shift strategy because a tuner is capable of doing more than simply adding power... which might make someone more interested in such a product when they are attempting to correct their speedo.

feel free to step off your high horse while you are literally guilty of everything you say bothers you about this forum... you have mocked modifications but choose to install a different size tire than the one that came from the factory and you would like to correct the speedo... regardless of whether the size was a factory option or not, it is a modification from stock... then you mocked people who prefer larger more aggressive tires which was completely off topic then proceed to lecture about staying on topic... the age stuff is just bizarre to me... if you were an active member here, you would notice there is actually quite a diverse mix of age... regardless of age, some people like to modify their trucks for looks, needs, convenience, sometimes just to see what can be done, other prefer not to at all (which is not the group you fall into, remember you modified your tire size and are looking to modify your speedo out of convenience)

Mod (Ret.)

Depending on the size tire/rim you are switching over to, the speedo may not be far off; especially if you are using a size that was offered by Ford for your particular year. It's easy to calculate the difference in speed by using the tire sites off of the internet. They allow you to enter your current stock setup, then the new rim/tire you are planning, and the spped calculator will tell you the difference in the speedometer reading. it might only be a mile or two different.