Speedometer reprogramming (1 Viewer)

[bryan8252]

So am I correct that this is still not possible? Even for a dealer?

I’m going to be putting on a set of Falken Wildpeaks and would like to get some 17” wheels and then have the speedo reprogrammed by the dealer.

But from what I’ve read on the forum that can’t be done. Correct?

Also, does anyone have a ‘22 or ‘23 GX with 17” wheels that would like to share a picture? This is how mine sits now… no plans on lifting it.

 

[r2m]

Any programming available for calibrating the speedo is vaporware.
You are correct, there is nothing out there that has been tested, reported and known to work.
There is this product, but nothing about it for sure working on GX's: Official home page of the Yellow Box Speedo Recalibrator - https://www.yellr.com/

If you really want to keep tab's on your speed, you'll need to use a GPS app from your phone.
Google maps will show the speed limit on the road you're driving and your current speed. If you're over the posted speed by less than 5 MPH, your speed will be shown in orange, if it's over 5 MPH your speed will be red. This has been very handy when traveling and if I miss any posted speed limits.

Personally what I'm doing, since I have 35" A/T's and my speedo is about 10% off, I use OBDLink app. It's a free app but I use it with the OBDLink MX+ bluetooth OBDII dongle. I have an old Galaxy Note 8 phone I have the app on and keep it plugged in and always mounted in my rig. Doing that, I don't have to always be using my current phone for the app, so I use my current phone when driving for Spotify, Google Maps or whatever since the Note 8 is dedicated to just being connected to OBDLink MX+ dongle.
Amazon product ASIN B07JFRFJG6

 

[bryan8252]

Thank you!

 

[Rednexus]

One way to do it *could* be a speedometer correction devise. On my much older 470 I'm going to be splicing in a Healtech Speedohealer to adjust the speedometer, odometer, and trip/mpg meters only. This requires cutting etc and not something you'd probably want to try on a new vehicle. They are not plug-and-play.

It looks like there are some off-the-shelf, plug and play options for the 5th gen 4Runner, like this one. Someone would need to do some research to determine if these might work for a 460, I personally have no idea.

 

[r2m]

On my much older 470 I'm going to be splicing in a Healtech Speedohealer to adjust the speedometer, odometer, and trip/mpg meters only.

Looking at Healtech Speedohealer(SpeedoHealer v4 (SH) - HealTech Electronics Ltd. - https://www.healtech-electronics.com/products/sh/) it looks like it's only for bikes. But if you can figure out the wiring, I guess it just might work!
If it does, please report back in!!

 

[MrTorgue]

If you've got carplay can you use Waze or Gaia to keep tabs on speed.

 

[r2m]

If you've got carplay can you use Waze or Gaia to keep tabs on speed.

Also Google Maps. Although I don't have Carplay, I assume you can do Google Maps there.

 

[MrTorgue]

Also Google Maps. Although I don't have Carplay, I assume you can do Google Maps there.

I don't think it has a way to track speed on iPhone.

 

[Rednexus]

Looking at Healtech Speedohealer(SpeedoHealer v4 (SH) - HealTech Electronics Ltd. - https://www.healtech-electronics.com/products/sh/) it looks like it's only for bikes. But if you can figure out the wiring, I guess it just might work!
If it does, please report back in!!

Another forum member already figured it out. I would have never come up with the idea on my own
I will report on my build thread.

Edit: Here is the 470 link. I have no clue if this would even be an option for a 460. One would need to have a deeper understanding of how the ECM/PCM etc work and where the speedometer and odometer pull from. FYWI, my 470 reads 4.5% slow with 265/70R17s. It was probably reading slow stock too.

 

[ericm979]

So am I correct that this is still not possible? Even for a dealer?

I’m going to be putting on a set of Falken Wildpeaks and would like to get some 17” wheels and then have the speedo reprogrammed by the dealer.

What size tires? My 265/70r17 Rubitreks (basically Wildpeaks with a slightly different tread) put the speedo maybe 1% low. Now rather than the speedo being high at highway speeds, it's essentially correct. This is the largest tire that you can fit in the spare tire space.

I have a Scangauge III on my dash and one of the displays I have programmed in is speed. This scangauge lets you adjust the speed that is displayed by a consistend factor. I kept changing it until it matches a GPS speedo at highway speed on a flat highway. At 75 it's like 1 mph different from the speedo. For me thats stil close enough that the speedo is useful. I do have to remember that it's not reading 5-7% high like most speedos.

 

[MrTorgue]

What size tires? My 265/70r17 Rubitreks (basically Wildpeaks with a slightly different tread) put the speedo maybe 1% low. Now rather than the speedo being high at highway speeds, it's essentially correct. This is the largest tire that you can fit in the spare tire space.

I have a Scangauge III on my dash and one of the displays I have programmed in is speed. This scangauge lets you adjust the speed that is displayed by a consistend factor. I kept changing it until it matches a GPS speedo at highway speed on a flat highway. At 75 it's like 1 mph different from the speedo. For me thats stil close enough that the speedo is useful. I do have to remember that it's not reading 5-7% high like most speedos.

^ This. My 265/70/17's are almost spot on.

 

[r2m]

At 75 it's like 1 mph different from the speedo. For me thats stil close enough that the speedo is useful. I do have to remember that it's not reading 5-7% high like most speedos.

Close enough to keep the local highway patrol/state troopers from bothering you!

 

[MrTorgue]

Close enough to keep the local highway patrol/state troopers from bothering you!

Exactly.

 

[Banandalorian]

What size tires? The speedo on my 2017 was off with the factory sized 265/60/18s and is accurate to my GPS with 265/70/17s.

 

[bryan8252]

I am keeping the stock tire size for now. I’d like to go to 17” wheels but I do like the look of the Blackline rims. I haven’t spent enough time researching wheels to have an alternative to the OEM ones.

That’s interesting that with stock tires your speedometer was off.

 

[Rednexus]

My 470 is a whopping 4.5% off with 265/70R17s. Must have been off with stock tires as well. I've had multiple vehicles with speedometers off with the stock tire size. No clue how that happens....

 

[ericm979]

That’s interesting that with stock tires your speedometer was off.

All road vehicles have speedos that read high and it's been that way for decades. I don't know why. Besides the obvious odometer reaches the end of the warranty sooner. Maybe to avoid lawsuits from people who got speeding tickets?

Another other car instrument that lies to you is the coolant temperature gauge. Even if it looks like a gauge with numbers, it's really a three position indicator: cold, ok, hot. There's a damping function between the states so it looks like a real gauge, but it's not.

 

[Rednexus]

All road vehicles have speedos that read high and it's been that way for decades. I don't know why. Besides the obvious odometer reaches the end of the warranty sooner. Maybe to avoid lawsuits from people who got speeding tickets?

Another other car instrument that lies to you is the coolant temperature gauge. Even if it looks like a gauge with numbers, it's really a three position indicator: cold, ok, hot. There's a damping function between the states so it looks like a real gauge, but it's not.

My 2018 Mazda 3 was dead on, as is our 2023 Highlander. Our 2014 Subaru Outback was around 3% off/fast. Either way it seems inexplicable to me - if it's reading fast fuel economy will be over-reported and maintenance will be done in intervals that are too long. If it's reading slow you get speeding tickets. I don't see why it's so hard for manufacturers to get them right.

 

[Banandalorian]

That’s interesting that with stock tires your speedometer was off.

My assumption was that Lexus decreased the tire diameter by an inch compared to every other J150 truck (4Runner, FJ, Prado) so the GX looked less "truck like" and was easier for old people to climb into but didn't change the speedometer since the difference is small enough to waive away as a margin of error. But maybe I just got conveniently lucky lol.

 

[r2m]

My assumption was that Lexus decreased the tire diameter by an inch compared to every other J150 truck (4Runner, FJ, Prado) so the GX looked less "truck like" and was easier for old people to climb into but didn't change the speedometer since the difference is small enough to waive away as a margin of error. But maybe I just got conveniently lucky lol.

Lexus is all about comfort and soccer moms when the GX came out. No one was really expecting people make their GX's do the same and better than their 4R cousins... until we figured it out! Ha-ha-ha!!!