Changing speedo for new tires after lift 23 bighorn

[Pumpniron]

So I’ve been searching this forum for a reliable way to correct the Speedo and shift points for my new. 2023 bighorn. I’m going to be putting a 4” bds lift with 35s on it in the coming weeks but I can’t find info on the new year with the parksense not being messed up. Rough county clearly states on theirs it will not work with park sense. I was thinking either the super chips flashcal or Tazer Dt but I’m not seeing another having success fixing the tire size issue and not cause other problems for the 2023 5.7 e torque
If anyone knows a device that works let me know please. I’m figuring I’m going to be spending 2-300$ on this but I want it right from the point it’s lifted. Thank you all

 

[JRD]

Interested to see the responses. I’ve been looking into getting new wheels and just saw the Tazer has this option as well.

 

[kdoublep]

Search AlfaOBD

 

[Pumpniron]

Ended up going with a Tazer Dt cause I want the function of auto fold mirrors plus I don’t own a pc or android lol all apple ios (iPhone,iMac). But I won’t have my lift and new tires put on till next week so I’ll post back up how it goes once they’re installed and I change the size on the Tazer. Seems easy to use though.

 

[kdoublep]

I used Alfa for tire sizes, turn signal drl's and Tailgate ajar warning. Would love to get auto fold mirrors. I think only Tazer can do that?

 

[JRD]

I used Alfa for tire sizes, turn signal drl's and Tailgate ajar warning. Would love to get auto fold mirrors. I think only Tazer can do that?

I’ve spoke to numerous people on here about this, and can confirm it is only available with Tazer. That said, I was told you could run Tazer & Alfa so that’s a plus (for me anyway)

 

[Pumpniron]

I used Alfa for tire sizes, turn signal drl's and Tailgate ajar warning. Would love to get auto fold mirrors. I think only Tazer can do that?

I believe so. To my knowledge Tazer is the only one who can do auto fold and I know some people don’t think it’s worth it but I’ve had someone knock a mirror off in a parking lot before lol. Feels like the truck should have just come standard like that but whatever. Wife’s Kia Telluride was about the same price and has about 20 plus features wish my truck came with. Maybe down the line I’ll put in the proximity keyless entry handles. Just looks like a PITA

 

[HSKR R/T]

I believe so. To my knowledge Tazer is the only one who can do auto fold and I know some people don’t think it’s worth it but I’ve had someone knock a mirror off in a parking lot before lol. Feels like the truck should have just come standard like that but whatever. Wife’s Kia Telluride was about the same price and has about 20 plus features wish my truck came with. Maybe down the line I’ll put in the proximity keyless entry handles. Just looks like a PITA

Havent seen many posts in last couple years, but I know the 2019s and early 2020s had issues with the gears stripping out for the power fold mirrors. I had auto fold enabled for a couple weeks and really didn't care for it personally, and with the reports of stripped gears, I just turned it back off. About the only time I fold my mirrors is in auto car washes, and if in a tight parking space, but I usually just try to avoid tight parking spots.

As for breaking the mirrors because they weren't folded, they should still fold when hit to prevent breaking. Of course that all depends on how they are hut I guess. I broke my passenger side mirror backing out of garage because the edge of mirror hit right in the corner between door trim and door frame and couldn't fold.

 

[Pumpniron]

So I ended up switching off the auto mirror thing cause y’all scared me with the motors blowing up lol but I did the tire size change and it’s been a ***** still not correct Speedo. Not sure what’s the best app is to use for correct speed but I’ve been using all different ones (so far wave and google maps seem the most accurate) and I measured my tires with a tape measure and level after driving a little and making sure all 4 tires have the same psi which my Kenda Klever art 35/12.5/18 are actually 33.67” tall which is news to me. But I put that in and my Speedo is showing I’m going about 3-4 mph faster than I actually am. I’ve contacted Tazer dt just waiting on a response now

 

[HSKR R/T]

So I ended up switching off the auto mirror thing cause y’all scared me with the motors blowing up lol but I did the tire size change and it’s been a ***** still not correct Speedo. Not sure what’s the best app is to use for correct speed but I’ve been using all different ones (so far wave and google maps seem the most accurate) and I measured my tires with a tape measure and level after driving a little and making sure all 4 tires have the same psi which my Kenda Klever art 35/12.5/18 are actually 33.67” tall which is news to me. But I put that in and my Speedo is showing I’m going about 3-4 mph faster than I actually am. I’ve contacted Tazer dt just waiting on a response now

I'm using line 34.65 for my 35x12.50r20 tires. Just keep adjusting the size and watch how it effects speedo to GPS speed. Took me three tries. Even using alfaObd, I tried helping another guy and took 6 adjustments to nail it

 

[BrandonSmith]

Tires are not exactly the size they say. 35s end up being 34.5 or 35.1, etc.

Before mounting a tire, wrap a string around the tire, mark where it overlaps. Lay it out straight, measure the length. You now have circumference. Just keep in mind the amount of tension you pull on the string should be the same when wrapping the tire and measuring it.

Diameter = circumference / pi

 

[HSKR R/T]

Tires are not exactly the size they say. 35s end up being 34.5 or 35.1, etc.

Before mounting a tire, wrap a string around the tire, mark where it overlaps. Lay it out straight, measure the length. You now have circumference. Just keep in mind the amount of tension you pull on the string should be the same when wrapping the tire and measuring it.

Diameter = circumference / pi

Except once you put weight on your tire, that junber changes

 

[DeanM2]

Before mounting a tire, wrap a string around the tire, mark where it overlaps. Lay it out straight, measure the length.

Diameter = circumference / pi

While the method described give you a good measurement for the true circumference of the tire, it does not reflect the actual circumference of the tire when it is on the vehicle and sitting on ground. A better method is to measure the diameter of the tire from the top of the tire to the ground, when the vehicle/tire is on the ground. Then do the math:
(Diameter of Tire) x 3.1417 = Circumference of tire.

 

[Eighty]

Or even better, draw a chalk line on the tire, then drive forward several feet. Measure from the first to the last line, and divide by the number of spaces you created (or number of lines minus one). That minimizes the measurement error.

 

[Pumpniron]

So I have it set to 32.96” and it’s still showing me 2 mph too fast
Have confirmed was other devices it really is off.
I guess keep going lower ? Not making much sense here lol

 

[HSKR R/T]

So I have it set to 32.96” and it’s still showing me 2 mph too fast
Have confirmed was other devices it really is off.
I guess keep going lower ? Not making much sense here lol

Take a big swing and see what happens. I was doing one where it didn't seem like it was changing much, so made a big change in numbers and realized I was going the wrong direction. After that it only took two more tweaks to get it right