Adjusting for Bigger Tires in FORScan for your F150 

Tools/Software Used: OBDLinkEX Adapter: amzn.to/3QOBmDC

For those asking! A dramatic change in tire size can/will affect transmission shifting and a sort of "dogging down" at highway speeds. It isn't actually "dogging down" but may require more throttle to maintain speed, and/or cruise control may have a harder time maintaining speed. This will fix those problems! Also - the reason his speedo is still slightly off - is because the tire circumference will slightly reduce (by ~3% at these sizes) when truck weight is put on them. You'll notice that the default setting in your truck has already accounted for this and is slightly lower than the original tire's actual circumference. To account for this, reducing the # in mm of your new tire's circumference by ~3% will make the speedo basically perfect.

For anyone who’s going from 18s to 20s. I put my tire mm to 2528 and it’s spot on . 2631 was off by 2-3Mph as he mentioned in the video. 2023 F150

I just used this video to calibrate my speedometer after getting new, bigger tires and it worked perfectly. Reducing the total mm of the circumference as suggested in another comment, my digital speedometer, regular speedometer, and the GPS speedometer all match. Thanks for the video!

Awesome video brother Thanks for sharing. Keep the videos coming. Hope you have an incredible day Much love and RESPECT

Glad I can do this myself! Got my off road tires taken off after hunting season, and it’s way off now. Thank’s for this video

Very clear instruction. Just put 35's on my 18. Thanks!

Great video!! Very helpful!! Thanks!!!

I got feedback from a viewer that the stock settings on an F150 with 275/60/20 is 2547mm. That might make a good starting point rather than just using the calculator directly. Keep in mind, different tire pressures may cause this # to be slightly higher or lower.

Nice calibration and fix!👍

Thank you. Now i just need to find my laptop and obd connector. It's been awhile since I used Forscan

I bought a RAM and the dealer has 35 12.5 r20 on 3 other 1500s also. I figured it would be calibrated, it's off 4mph at 40 and 8 mph off at 75. Your gear is so simple- nut the dealer says RAM won't allow them to change it. That's nuts. I really don't care about mph or mpg but it's wrong on the odometer and other sites says it damages the transmission. If this truck can tow 8 to 10,000 pounds, I can not see a tire change doing anything to the transmission. But I flat don't know. Thanks for a good video showing some trucks can be changed.

I came for the information, I stayed for the information and the fact that when he said forscan it sounded like foreskin and I’m an adult child! Haha Definitely subscribed though! Good info!!

Thank you

Do you have to change rhe number back before service or is this a one and done thing? Thank you for the video

Can u answer me a question? I have a focus St and I have tire size 235/35 19 with 1975mm in bcmii module and also in IPC module but the odometer tells me allways to much (drive with 100km/h odo shows 107 km/h) If I want reduce the shown speed to 102 km/h I will like insert 2005mm. Is it right that I take the changes only in IPC module and not in the bcmii module? If I change IPC and bcmii module, there is no difference (shows also 107km/h on 100km/h speed) Hope you understand, but I am from Germany, thx😊

By doing this, do you think it’ll up the transmission? I noticed after changing my tire size and not correcting it in the computer. The transmission seems to shift differently than it did with the stock size tires

I NEED to do this for my Bronco! However, I don’t own any PCs as my (as well as most of my friends and family’s) home OS is Mac based! I really don’t want to buy a used PC to only use once!😞

on my car im going from 205/50r17 to 215/55r17... but even with calculator still 2~3mph (similar issue), any ideas?

What would my value be if i have 33x12.50r20 tires? One website tells me 2617 while the other one says 2631

Mine is still off but not til i reach about 40mph and it gets worse the faster i go. 2011 f150 with 305/45r22. Calculator said 2616 which i tried then i went up a few times all the way to 2700 and gave up

I just change the tires of my F150 2018 from OEM to 275/65/20. My gas went crazy and I noticed the transmission shifting is a little bit wild from time to time. Would forscan will fix this if the circumference will be calibrated as close as possible? Any magic number for 275/65/20?

I have S-Max 2016 (mk2) which is basically fusion/mondeo/galaxy/edge. So, i use 235 /55 R17 tires. Original value was 2098mm and i changed it to 2167 as calculator gave me this number. Originally (thnx for stupid Eu rules real speed must be lower than speed on your clock) at 90kmh real speed (gps) was about 86kmh. So after putting new value i got 82kmh (gps) and 90 on the clock. That means foult was doubled. I restored old values. I noticed there was smth like Speedometer logic or smth. Mine value was Europe and i changed it to North america. And then fault was only 2kmh, 90 on the clock and gps 88kmh. So i went back to tire circum and put not 2167 but -69 (2098-2167) from original value that means 2029. After that i got 90 on the clock and gps 92. Then i made some more test and righ now there is 2050 value which gives me at 90 on the clock and less than 90,5 kmh by gps and 50kmh on the clock and 49,xx on the gps. Soon i gonna put summer tires back and will check and correct those values again. PS have been in US many times and always checked rental car speedos with gps, and always fault have been less than 0,5mph.

Hello, Do you have a video how to fix Vin #? ===PCM DTC P0630:00-AF=== Code: P0630 - VIN Not Programmed or Incompatible - ECM/PCM

can I use it for gmc sierra 2023

Will it work with a 2024 Ford Maverick Hybrid?

I just did this and now I got a wrench light. Unable to clear it, P160A in TCM.

If I’m just changing the rim size do I have to do this ?

I did this but my Speedo is still off. Any ideas on what else to try?

After changing the size of the tire and resetting the transmission table I got this error message. Any idea how to get this fix? ===PCM DTC P0630:00-AF=== Code: P0630 - VIN Not Programmed or Incompatible - ECM/PCM Status (-AF): - DTC Present at Time of Request - Malfunction Indicator Lamp is On for this DTC ===PCM DTC U0422:00-2F=== Code: U0422 - Invalid Data Received From Body Control Module Status (-2F): - DTC Present at Time of Request - Malfunction Indicator Lamp is Off for this DTC Module: Powertrain Control Module ===END PCM DTC U0422:00-2F===

Hi there, i have question. I add a hub spacer 2inches or 50.8mm . Don i have to add that in tire calculator? For example i have a tire 275/65/r20 would that be 325/65/r20… this changes the circum from 2718 to 2921?

But your miles would read less without this calibration. I put 32"s on my 1998 Wrangler and was reading much less speed and miles. THen I put the stock wheels back on when i traded it in for something else :)

its a perceentage, so the faster you go the more its off... I have 285/70/17 and was off about 10% so when the speedo said 60 I was actually doing 66, I havent bothered to change it yet, I just know in my head 64-ish will be 70 LOL

Does forscan work with Apple MacBook?

Tried but keeps stopping at 17% any ideas?

F150 forscan hybrid

This video seems wrong, more steps are required to actually apple the new tire size information. At least on my F150. Ive run into this and numerous others have.

I swear he saying 4skin

Did you say Fore-Skin? Bruh 😅😂

Does any1 know what is the number should be when going from stock tire to 35 for 23 f150? Thanks