Kefka92

Just got my truck leveled and put bigger tires on. Went from 265/60 18s to 275/60 20s. Gained quite a bit of circumference and the revs per mile are about 50 less. So i know my speedometer is quite a bit off.

But since nobody can calibrate the speedometers on 2016 I was looking into the Hypertech Tool and had a few questions...

- I know this changes Speedometer, but what about the odometer?
- Will this also correct the oil life readings?
- Will this change how the transmission shifts? I heard you may need to re-calibrate the transmission as well? Not to sure about this...
- Lastly, will this void the warranty/extended warranty?

Thanks!

Canadian F150 Owner

Why spend $260 on the reprogrammed!

Order an OBDII adaptor for $80 and download FORSCAN software for free and make the change yourself. Easy to do. I have done my truck and my son's truck.

GregSBF

Can't say I'm super impressed with the speedo calibrator I just received. I put on 33.25 tires from the factory 31.75 tires. Well I'm down to 31 on the calibrator to get my speedo correct? I can see being out by a little but 2"?

Kefka92

Once I have the software and the adapter what do I do? I was reading through the FORSCAN thread and didnt see anything on speedometer calibration

Kefka92

You got the hypertech?

Canadian F150 Owner

For FORSCAN read the first page again and also review the spreadsheet published by livnitup (he has done great work on F150 FORSCAN and others). In the spreadsheet there is a BCM tap, go down to address 726-12-01 and follow the instructions there. There is also another spreadsheet there that Spartans published, this is a good reference on where to start. The value that you are changing is actually the tire circumference in milimeters (but changed into Hexadecimal).

So what I did was downloaded a GPS speedometer app on my cell phone to measure the actual speed, made the change up or down depending on how much you were out. I found that 1 km/h (0.6 miles/hour) equels 10mm.

This modification will correct everything that the Body Electronic uses (Speedo, Odometer, MPH Calc., Trip Odometer). It does NOT change or modify the shift points. You should also be aware that this mod does trigger a very minor trouble code for a mis communication between the PCM and the BCM, this does NOT trigger a service engine light to come on. But like I said very minor, even an unmodified compuer over time will have multiple communication mismatch warnings.

GregSBF

Yes I have the hypertech.
Funny I started out at 33.25 and the speedo read about 5km slow. I went down by .5 each time till I got to 32.25 and I was really close at this point. 31.75 was closer yet but at 31.25 it started going the wrong way again? Speedo reading slow? I went to 31.0 and it was worse again. Back up to 32.0 and bang on? I'm not sure how or why but it seems to be reading correctly now?
Long story short it works but I might go with the forscan next time.

Kefka92

Thats strange that you had to go down to get the speedo correct? You would think you would have to go higher than 33.25.

What did you do to test if it was correct or not?

StangMan04

I had to go to 31 for my 275/60/20 (33s) on mine too to match gps. Appears to be the norm from what I have seen.

GregSBF

I used a little hand held Garmin gps. I'll check again in a day or two. It seems odd how it behaved and now I'm wondering if maybe my sat signal was degrading for some reason? Seemed to like 32" though?