Plug and play speedometer calibration

[I Lean]

No affiliation with the business, but I wanted to share how pleased I am with my speedometer calibrator I got from Lutz Auto. I initially bought a "beta" model based on another thread here...I did have a couple issues with it that are unusual. Long story short, after it made a couple trips to the manufacturer and back to me, he ended up sending me a new production model.

I know for sure, every business/product will have some failures somewhere. Bryan Lutz MORE than went out of his way to make sure everything worked properly for me, and I really appreciate it.

The programming is super simple--just buttons to click "up" or "down" depending on how you need to adjust your speed reading.

This shows the original beta model, under the cover:



And this is where I mounted it. Just drilled a couple holes in the sheetmetal "wing" thingies on my Tcase, and zip tied in place.



And here's where I ended up mounting the production model, since it's a little wider than the beta. Just zip tied again, but this time to the fuel lines just in front of the fuel tank.



I really like how easy it is to calibrate, and future adjustments will be just as easy if/when I make changes. I also really like having an accurate speed reading, which is a new experience for me in this vehicle.

Link to Lutz Auto page: 80/100 Series Landcruiser & LX450/LX470 Speedometer Calibrator | Lutz Auto

 

[Swbkrn2003]

No affiliation with the business, but I wanted to share how pleased I am with my speedometer calibrator I got from Lutz Auto. I initially bought a "beta" model based on another thread here...I did have a couple issues with it that are unusual. Long story short, after it made a couple trips to the manufacturer and back to me, he ended up sending me a new production model.

I know for sure, every business/product will have some failures somewhere. Bryan Lutz MORE than went out of his way to make sure everything worked properly for me, and I really appreciate it.

The programming is super simple--just buttons to click "up" or "down" depending on how you need to adjust your speed reading.

This shows the original beta model, under the cover:



And this is where I mounted it. Just drilled a couple holes in the sheetmetal "wing" thingies on my Tcase, and zip tied in place.



And here's where I ended up mounting the production model, since it's a little wider than the beta. Just zip tied again, but this time to the fuel lines just in front of the fuel tank.



I really like how easy it is to calibrate, and future adjustments will be just as easy if/when I make changes. I also really like having an accurate speed reading, which is a new experience for me in this vehicle.

Link to Lutz Auto page: 80/100 Series Landcruiser & LX450/LX470 Speedometer Calibrator | Lutz Auto

Just got mine is it plug and play? Been too busy to even open the box

 

[I Lean]

Just got mine is it plug and play? Been too busy to even open the box

Yep. Unplug the stock plug from the Tcase, and plug the two connectors of the calibrator in between. Then turn the key on, click your "up" or "down" buttons as needed, and button it back up.

In my case (4.88 gears and 315/70/17 tires), I needed 9.5% correction...so I clicked the "down" button 19 times.

 

[Swbkrn2003]

Yep. Unplug the stock plug from the Tcase, and plug the two connectors of the calibrator in between. Then turn the key on, click your "up" or "down" buttons as needed, and button it back up.

In my case (4.88 gears and 315/70/17 tires), I needed 9.5% correction...so I clicked the "down" button 19 times.

Perfect thanks! I have 4:88 gearing and 35's

 

[LLTB]

I just bought one of these. I'm running 35" tires with stock gears. How can I determine how many times to "click" to get an accurate speedo reading?

** EDIT **

Answering my own question here...

Take the rig for a drive between 55-65 mph. Using an app like Google Maps or Waze that shows you what your current speed is, make a note of what the GPS speed is compared to what the factory speedometer says.

(Actual or GPS speed / Speedo Speed - 1 ) * 100 = Percentage difference, round to nearest 2 digits

(65 mph / 59 mph -1) * 100 =
(1.10 - 1 ) * 100 =
0.10 * 100 = 10%

Each button press is 1/2% change, so you need to press the UP button 20 times to speed up the speedo by 10%.

 

[JoeCova]

The speedo difference mathematically between 275/70R16 (Stock) and 315/75R16 with 4.1 (stock) and 4.88 gears is only 6.6%

 

[lumbee1]

The speedo difference mathematically between 275/70R16 (Stock) and 315/75R16 with 4.1 (stock) and 4.88 gears is only 6.6%

Yeap, but with the differences in tire sizes between claimed and actual, it is best to calibrate with GPS speed. My Lutz Auto calibrated speedo is more accurate than my wife's factory speedo in her MDX.

 

[JoeCova]

Yeap, but with the differences in tire sizes between claimed and actual, it is best to calibrate with GPS speed. My Lutz Auto calibrated speedo is more accurate than my wife's factory speedo in her MDX.

The difference in claimed vs actual tire size assuming +/-0.5” is only 1.3%. That’s +/- <1mph. Aka moot.

GPS margin of error is up to 2mph mostly.

Should be ok if you can get them reporting between 1-2 mph of each other

So theoretical speed should match mechanical speed. GPS should be reporting actual ground speed which is usually always lower than mechanical speed:

EDIT: For discussion i did a quick trip to measure GPS speed, mechanical speed and theoretical speed for 315/75R16 and 4.88

@1450rpm; 38 GPS, 40 Mechanical, 40.16 Theory = 5%
@1800rpm; 47 GPS, 50 Mechanical, 49.85 Theory = 6%
@2500rpm; 65 GPS, 70 Mechanical, 69.24 Theory = 7.1%
@2900roml 74 GPS, 80 Mechanical, 80.32 Theory = 7.5%

 

[LLTB]

Got this installed. Took speed samples at 40, 50, 55, 60, 65, 70 and 75 both actual (GPS) and indicated, then averaged those and ended up doing 12 clicks up on the Lutz. took 10 minutes to do the install and 5 minutes of that was degreasing and struggling to disconnect the connector.

Indicated speed now seems to match GPS about 95% of the time. Good enough for me!