I haven't gotten a chance to go have my speedo / odo calibrated, after adding my larger aftermarket tires.... But since my size upgrade was not that extreme {only went from 30.3" stock Michelins, to 32.7" BFG AT's} I didn't think it would be that much....

So, just now, I decided to find out exactly how much.

As it turns out, the Michelins turned 693 rotations per mile, while the BFG's only turn 636.

So, 693, divided by 636 = 1.089. This works out to almost a 9% difference ! Which means I will have traveled 109 miles, when my odo says 100. But more importantly (to avoid expensive speeding tickets) I will be traveling at 65 mph, when my speedo says I'm only going 60 mph !

Wow. Just taking a wild guess, I figured maybe only a couple mph difference. Hmmm. Learn something every day :-)

I guess I do need to get the truck calibrated ASAP....

Peace,
Fish

 

Tuners will calibrate this too if I am not mistaken. Had you planned on getting a tuner?

 

And the faster you go, the further off your speedo is. I love the fact that my tuner fixed the problem. I feel a lot more confident when smokey pulls out behind me.

 

Hey Blue, my opinion about tuners is about as "far left" as it is about the rotating of tires.

Don't get me wrong, I think for some guys, in places other than Cali, who just have to have that extra few HP's, and don't mind screwing around with stuff that often needs to be messed with, and tweaked on, until you get everything dialed in just right.... Sure. Get a tuner.

But for myself;

1) I don't need "any more HP's whatsoever". In fact, I'd give you a few of the HP's I have right now, for a few extra MPG's.

2) They are not street legal in Cali. Okay granted, the odds of somebody getting in trouble for using one on public roadways is slim to none.... But if anybody ever did get nailed for it, it would be me.

3) Tuners void the warranty on a brand new truck. (mine is brand new). Again granted, should you have a problem with your truck "you might" be able to uninstall the tuner, to where a dealer could not tell you were using one {their seems to be conflicting info on this subject} but personally speaking, I wouldn't even want to be in a position, where I had to lie about anything.

4) If I'm going to spend big bucks (to me, $400 or $500 is big bucks) on an item, I want that item in less than a week. On this note, I still see no reason why these places can't do a custom tune for you, if not the same day, then at the very least, by the end of the next day. From what I've heard, an experienced tuner person, can program a tuner in 30 minutes or less. So then, he should be able to do 15 a day. If the company is consistently getting orders for 30 a day, I think they need to hire another programmer.
There is "absolutely NO reason" a guy should have to wait several weeks, or even months (like I see guys complaining on here all the time about) for a custom tune.

Anyway Blue, yes, tuners can calibrate your speedo / odo, and even shift points, and to me, this means even more than the performance features of a tuner.... But I have a place lined up locally, that will do this for me for $95. {funny when I see people say that dealers can do this for like $80 or $90... Ha ! Around here, the dealers want $200+}

Peace,
Fish

 

I see your point. Mine is brand new as well. I want a gas milage tune though. LOL. I wonder if someone who has a tuner could loan it to you just to calibrate the speedo? Can this be done? Not tune the engine, just calibrate the speedo.

 

No. The tuners are designed to "marry" themselves to a truck which prevents you from doing this. If they were not designed this way a group of guys could buy one tuner and do all of there trucks or charge people to tune trucks.

 

How convenient.

 

and hey Blue, remember, our F150's (well, all new vehicles for that matter) already have an onboard computer, which is capable of being adjusted (to some degree, albeit, probably not to the extremes of an aftermarket tuner) but I'm thinking / hoping, that because I 'only' went with 33"s, that the stock computer will be able to fully compensate for this change. Where on the other hand, if a guy went with 35"s, or even larger, he would probably either have no choice but to get an aftermarket tuner, or live with his speedo / odo reading incorrectly.

Peace,
Fish

 

Why don't you just add 5mph to what ever speed your driving and save yourself the hundreds of dollars to reprogram it. Thats what I do with my 22's. During the summer months I just add 3mph to the speed I'm driving, then when I go back to my OEM wheels for the winter, the speedometer is spot on. And if your odometer is only showing 100 mile driven for 109 actual miles driven, why would you want to change that. Eventually when you go to trade it in or sell it, it will look like it has less miles that it actually has.

 

Its not that easy.

The faster you go the more the speedo is off! My speedo is close to 16% off.

when im traveling 45 its really 52 but say if i was going 75 id really be going 87. (however my truck never goes that fast)

 

Loving the extra 3+ MPG's I'm getting thanks to my tuner. It's paid for itself already, and I'm still saving money.

 

Fish, tuners can help your MPGs as well as power. Im in Cali, i run custom tunes, but dont have a tuner on the dash with gauges etc. my dash looks stock. But my 5.4L 4x4 supercab is getting almost 20mpg highway (70mph) and is probably throwing down ~250rwhp compared to 205 stock. The tranny shifts better, the driveability is better, it is beyond worth it. However, my truck is also way out of warranty....but once yours is too, i'd go for it.

 

Yes, I know that tuners can help a little with mileage, and again, that's the part that means more to me. But that doesn't take away the other negatives I mentioned about tuners.

So anyway, "even if" I ever got a tuner, it would be way down the road, after my warranty was expired. And knowing myself, by that point, the newness, and excitement of the new truck will be long gone, and it's doubtful I'll be thinking about any new mods to the truck.

Again, I know their area lot of good things about tuners, but for me, they just don't outweigh the negatives..... especially at this point in time.

Peace,
Fish