Speedo calibration on 3rd Gen Tacoma

Yeah my guy told me to stuff it, so I smiled and drove away..........

 

Don't know, they never sent me any form after the 1st service check like they said they would. At the time they said they'd mail me it due to their computers and internet were down from the tropical storm we had. Whatever it was i'm happy, seems everything functions well. Imo, it almost seems like the truck was originally calibrated for taller tires.

 

Hey what's up. New guy here. I installed the RC one in mine because I bought it with 285/65R18s. I have it pretty well set. My question is this...did anyone running the RC one have issues with cruise being lower than actual speed set...like if I want to cruise at 70mph, I have to set it for 68mph...and, is anyone's odometer reading too short? Based on traveled distances charted in mapping programs vs. odo readings, I am short. Firmware is up-to-date and software is G2G. Any ideas?

 

My understanding of these is that they can only correct the speedometer - you'll still need to manually adjust the cruise and your odometer will always be wrong. It just touches the signal coming from the ECU to the speedo gauge, it doesn't actually change the way data is recorded.

 

From the manufacturer's website:
"...In-line Speedometer Calibrator Module is an in-line module to correct the speedometer and odometer for non-stock tire sizes and/or rear gear ratios..."

When I installed mine, it did indeed fix my speedometer, odometer and shift points. I still have an incorrect reading on the cruise control set speed, but others have reported a recent software update may have fixed that - I have not gotten around to updating mine yet so I cannot confirm.

 

I have an '18 but I ran the 19-20 option. Seemed to do the trick. Unless I am hyping myself, it seemed to work better. Shift points were better, I am maybe a couple decimals slower than reported speed but for the most part lines up...fine by me, and my Cruise seems to finally line up basically. Odo is running at about 97% of actual mileage. I just decided to live with it. I read SAE says ODO should be +/- 4% so I am within a spec...RC nor Hypertech ever reached back out to me. I ran updates and tried to update firmware probable Thursday night, but it is up-to-date. Whatever, it works as far as I know. Thanks!

 

I just installed the Rough Country version in my 2020. Before the install, with 32s my speedo was showing 2 MPH slower than I was actually going, according to GPS. I measured both tires (off the truck) and put those measurements in. Now, after the install, speedo says I'm going 1 mph faster than I actually am, again, according to GPS. Looks like I'm gonna have to tweak it if I want it exact, although it's probably close enough. The good news is I secured the USB cable to the module and left it attached with the computer end accessible under the dash, so now I just have to plug it and and upload the adjusted numbers if I decide I want to change it.

 

Yeah I did the same with the cable, It took me 3 times to get it dead on. One time I went the wrong way when adjusting so technically twice lol

 

I have a 2019 regeared with Nitro 456 and 35s? Off about 7mph. I'd like to have it accurate...is hyper tech still the only option?

 

Rough Country sells 1 which looks like a private label unit supplied by Hypertech (but I could be wrong)

 

And cheaper.

Have it, works fine .

 

Do people have both the Speedo calibrator and OV tune? Or can OV tune also calibrate the speedo and mileage?

 

No OVT doesn't do speedo/odo

 

I have both they work good together!

 

I have both as well. The hypertech/RC module simply intercepts the signal from the computer and modifies it for the gauge cluster to correct the readout/odometer.

OV tune is completely different and far more beneficial.

I have 285/75/16s and my truck was only off a few miles per hour at 60.

 

What's the best place ($) to buy one of these bad boys?

 

Maybe confused here. I'm having 285s put on a new 2021 Pro I'm getting in a few weeks, and what them to adjust this at the dealer before I take delivery. Can this be an internal adjustment they do or will they sell me this module?

 

Neither. There is no internal adjustment for different tire sizes, you will need to buy a speedo/odo calibrator - whether it be the Hypertech or the Rough Country (re-branded Hypertech). It's unlikely the dealer will sell/install it for you.

 

I’ve scanned through here, but can’t find a solid answer. Are their calibration options for a 2021?

 

Unless you're going to a huge tire it simply isn't worth the difference. If you upgrade to a 285/75/16 from stock you're only going to be off by 5 mph at 70. And as tires wear down from use they get smaller. The 285's with 40,000 miles on them will only be off by 2 mph. Even if you calibrate it now, it will be off later.

Of course that is true with all tires, in all sizes and always has been true. It's just that before GPS we never knew it. It is impossible for manufacturers to calibrate a speedometer 100% accurately since the tire diameter is constantly changing due to wear.

It ain't rocket science to understand that between 70-80 mph your speedometer is reading 5 mph slower than you're actually traveling. No cop is going to write you a ticket if you're less than 5 over, most give you 10. And at speeds under 50 mph you're not off enough to even care about.

Use this site to plug in the tire sizes and see how it effects you. Bear in mind that these numbers are only accurate with new tires. As they wear down the numbers change. As to the odometer. The above link gives you a percentage difference in tire circumference. If you're 7% bigger, then your odometer is 7% low. When calculating fuel mileage simply multiply the miles on your trip meter by 1.07 to get an accurate miles traveled. For example if your trip meter says you drove 278 miles you multiply 278 by 1.07. You actually drove 297.4 miles