Speedometer calibration

Interesting... any numbers you can put to this to quantify it? I have 35K miles on my stock 265/70R16s and am strongly leaning towards moving up to 265/75R16s myself when the time comes later this year. Up until I read your post, I've been thinking that both the speedometer and odometer will need to be recalibrated...

 

I'm on my 3rd Tacoma (a 1st, 2nd and 3rd gen), and the speedometers read 2-3mph high by a couple MPH on all of them from the factory. Slightly upping tire size usually puts them dead on. Use your GPS on your phone while driving to verify true speed.

 

As it has been mentioned. When I went to 265/75/16 the speedo reading became more accurate based on radar and GPS.

 

I'll be lifting my 2022 soon and putting on 275s or 285s. Looks like hypertech or RC don't support 22 Tacos yet. Has anyone tried on one yet?

 

I went to 265/75/16 and mine is off by 2MPH. If I do 55 indicated in the truck, I'm actually doing 57MPH. Confirmed by a cop friend of mine I asked to radar me driving down the road- as every one of these speed radar boxes they have on the sides of some roads were all showing 2mph off. He calibrated his radar unit at the start of his shift, he clocked me an hour after that. 37mph clocked when I was doing 35mph on the truck speedometer.

2mph isn't enough of a concern for me to justify spending $170+

 

Interesting... and how about your odometer?

 

In my experience everything gets corrected including mileage odometer readings and speed. I have checked this with my gas buddy app and the mileage calculations manually and on my display are really close overall. Gas buddy calc showed 17.5 mpg and truck readout showed same. I recently ran my truck well into the empty range on a trip in fact I went 2 miles past the point where the gas fill up light came on, and I had space for 1.6 gallons based on manual calculations. I’d say that’s close enough. I checked the speedo setting while on cruise control with my GPS app on my phone and they matched over about a 5 mile stretch. I don’t know anything about the transmission shifting. I guess I haven’t noticed it seems to shift OK. Not sure I would notice if it did not.

 

Awesome, appreciate the feedback.

 

Not yet mentioned in this thread is the possible difference between a corrected speedometer/odometer and the Cruise Control speed display. From other threads on this topic, I understood these devices (Hypertech or RC) do not correct the Cruise Control displayed speed. What are you guys finding?

I know there was a post above that said the dealer could not adjust the speedometer for a reason; I have found dealers to not be as honorable as they could be in stating the true reasons for their inabilities, so that makes me ask the question "Could Tech Stream take care of tire size changes?" After all there are differences in stock tire sizes, that I am assuming the factory adjusts for accordingly, that adjustment I assume would be with Tech Stream. As of yet I have no experience with Tech Stream, just putting this out there for consideration.

Another item I see in this thread is some posters are using gear ratio changes as a reason for either the Hypertech or RC. My understanding so far is the speedometer display on the dash is derived by the four speed sensors on our hubs and not within the transmission or transfer case. This would make it so only a tire size change would affect the speedometer display. Please correct my understanding if incorrect.

 

From what I've read, the cruise control speed will be off and there is no way to fix it.

The speed sensors are in the wheels so you do not need to change the gearing for the Hypertech/RC calibrator. Only change the tire size.

 

My electronic digital speed seems right on with cruise control set. This is how I checked it! Had my phone with GPS app running right next to it.

 

Anyone with 255/85r16's notice if their reading are actually closer to true?

 

My stock 2021 OR was right on from the factory. Haven't ever had a speedometer so accurate. Compared with two GPS units. However, when I changed to 255/85/16 my displayed speed is lower than the real speed. Displayed 61MPH, real 65MPH.

 

I am looking at getting my speedometer recalibrated using one of the aforementioned units. Does it matter if I have 4wd or rear wheel drive? When I select the rear wheel drive for my truck on the websites it says not compatible. Anyone w non 4wd install this on their truck? Any help would be appreciated. Thanks

 

Installed on a 19 tonight. Cannot get it to work. Wondering if windows 11 is the prob? Says successfully programed (30.6” to 32.8”) I go plug it in n nodda. Tried 6 times. Frustrated atm. Only thing I can think of is it’s windows 11? Website mentions up to windows 11

 

It could very well be. I tried it on an older laptop and I could not get the drivers to install. My son did it on his MacBook and it worked perfect.

hope you get it figured out soon.

 

This might be a stupid question but will this work if your truck is tuned?

 

The only stupid question is the one unasked. Yes, the calibrators work despite a tune.

The wheel sensors are the only place speed is sensed on these 3rd gens.