Is there a way to calibrate the speedometer on our Gen 5s? - Toyota 4Runner Forum

david05111 · 01-24-2021, 08:03 PM

I was out in my 2020 today and noticed that my speedometer seems to be off, based on what my GPS is saying.

My car will read 70 MPH, but the actual speed is like 67-68 according to GPS.

It's a TRD Pro, so I thought initially that it might have been because of the different wheels and tires, but it it would read the opposite if that were the case.

It sounds inconsequential, but at that rate if the car has actually done 100k miles, the car will read almost 104,500. That's almost 4500 miles, and not insignificant.

Can Toyota handle this?

Nobody Special · 01-24-2021, 08:10 PM

We used to take two Siennas on a 700 mile trip regularly.
One would have 60 miles less over the course of a one way trip, 120 round trip.

OEM wheels and tires on both.
One '03. One '04.

mo_mo · 01-24-2021, 08:21 PM

Quote:

Originally Posted by david05111

I was out in my 2020 today and noticed that my speedometer seems to be off, based on what my GPS is saying.

My car will read 70 MPH, but the actual speed is like 67-68 according to GPS.

It's a TRD Pro, so I thought initially that it might have been because of the different wheels and tires, but it it would read the opposite if that were the case.

It sounds inconsequential, but at that rate if the car has actually done 100k miles, the car will read almost 104,500. That's almost 4500 miles, and not insignificant.

Can Toyota handle this?

The regular answer is no you can't calibrate it.
The more complex answer is anything is possible, but you're not going to want to do it (there are several previous conversations on this forum about it).

FYSA, TRD Pro comes with the same size (265/70R17s) that all other 4Runners come with (except the 20" limiteds).

Upgrade your tire size to 285/70R17s and your speedo will match.

I'm not sure that the speedo and total (not trip) odo are tied together at the same ~4.5% mismatch.

zcruiser · 01-24-2021, 08:29 PM

I use an iOS app called Spyglass to check my speed correlation in all my vehicle so I know if it’s reading high or low, typically calibrate at 70 mph as measured by Spyglass to know if my speedo is reading high or low.

david05111 · 01-24-2021, 09:15 PM

Quote:

Originally Posted by mo_mo

The regular answer is no you can't calibrate it.
The more complex answer is anything is possible, but you're not going to want to do it (there are several previous conversations on this forum about it).

FYSA, TRD Pro comes with the same size (265/70R17s) that all other 4Runners come with (except the 20" limiteds).

Upgrade your tire size to 285/70R17s and your speedo will match.

I'm not sure that the speedo and total (not trip) odo are tied together at the same ~4.5% mismatch.

Thanks. That’s mind-boggling that it can’t be calibrated, but it is what it is.

Tuco S. · 01-25-2021, 05:38 AM

Your speedometer is calibrated, just not to the P265/70R17 (31.7" diameter) factory tires. Get some 33" tires and it'll be right as rain. I'm running LT255/80R17 Toyos and it's dead on with gps, as well as those radar controlled speed signs which I've specified on a few projects for the state DOT and verified they are accurate.

Jeremy556 · 01-25-2021, 11:20 AM

Quote:

Originally Posted by david05111

Thanks. That’s mind-boggling that it can’t be calibrated, but it is what it is.

It used to be easier when the speedo was based on the output of a single sensor from the transfer case. In the 5th gen, it is generated by the 4 ABS sensors, so you would need to modify the signal with 4 devices.

2Biglabs · 01-25-2021, 01:22 PM

Im surprised no one has made either a FTC or NTSHA complaint about this.

Due to the speedometer being different it would affect your warranty. I realize that its usually in the consumers favor, but what if its not?

I also wonder if it affects the vehicle stability system or the abs negatively. Im sure there is some Toyota tech or other manufacturer tech that could tell us if it does. IIRC when i had a GM product it was in the owners manual that aftermarket wheels could mess up the system.

The error, while annoying, is something I can deal with. Getting hurt cause the sensor (abs,vds) is off is not.

Jeremy556 · 01-25-2021, 03:25 PM

Quote:

Originally Posted by 2Biglabs

Im surprised no one has made either a FTC or NTSHA complaint about this.

Due to the speedometer being different it would affect your warranty. I realize that its usually in the consumers favor, but what if its not?

I also wonder if it affects the vehicle stability system or the abs negatively. Im sure there is some Toyota tech or other manufacturer tech that could tell us if it does. IIRC when i had a GM product it was in the owners manual that aftermarket wheels could mess up the system.

The error, while annoying, is something I can deal with. Getting hurt cause the sensor (abs,vds) is off is not.

It is within an acceptable margin of error.

The ABS and stability control systems are concerned with wheel speeds relative to each other, hence don't care about wheel diameter/exact overall speed

2Biglabs · 01-25-2021, 06:26 PM

Quote:

Originally Posted by Jeremy556

It is within an acceptable margin of error.

The ABS and stability control systems are concerned with wheel speeds relative to each other, hence don't care about wheel diameter/exact overall speed

Thank you!

Whippersnapper02 · 01-25-2021, 07:46 PM

Since my 2nd gen Tacoma days, the speedo has always been off but the odometer is correct on stock tires. Just drive.

pcstockton · 01-26-2021, 12:05 AM

Get a ScanGauge and set its speedo with a GPS speed like GAIA or something. Done.

I do that. I need +6% to match my 295/70/17s. You will also get correct MPG.

Bonus! You get less miles on your rig if you dont correct it.

rayofsi · 01-26-2021, 12:25 PM

the speedohealer might work? all the information is fed to the speedometer by one wire at the speedometer? Some information like mpg etc might still be off, but the display can possibly be corrected. I have too much stuff i'm working on and haven't had time to try to splice the speedohealer in yet.
I'm running 285/75r17 on 4.88 gears, definitely have a speedometer reading too low at higher speeds.

david05111 · 01-26-2021, 02:57 PM

Quote:

Originally Posted by pcstockton

Get a ScanGauge and set its speedo with a GPS speed like GAIA or something. Done.

I do that. I need +6% to match my 295/70/17s. You will also get correct MPG.

Bonus! You get less miles on your rig if you dont correct it.

Except it's the opposite on mine. When I drive, the car think's I'm driving more miles than I actually am at the moment.

For instance, the car reads about 8000 miles right now. Based on the error, the car has actually traveled between 7650 and 7700 miles. That impacts on my warranty and resale at the very least.

Of course I wouldn't object it it was in my favor, but it's not. The only solution seems to be go up in tire size, which seems kind of funny. We as off-roaders wouldn't object to that too much, but still

badattitude · 01-26-2021, 03:04 PM

I believe the speedometer is intentionally less than actual and the odometer is dead accurate. Have you tested the odometer against the GPS?

My GPS says 70mph when my Speedo says 69mph on 265/70/17s. Speed has always been a MPH under on my 4runners. I tested the ODO many years back on a 3rd gen. While the speed was off, the ODO was accurate.

Its all computers now. The speed and ODO are no longer linked in a linear fashion.

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