Hypertech3400 Speedometer Calibrator with Color Screen, 5.25 x 2.5 x 9 inches

This worked remarkably well. Recalibrated a 2019 Ram 1500 recently without trouble.Software updates:Installed software updates on a PC without issues immediately after receiving product.Quality:Build quality is sufficient to me. The screen size is awesome and cables are great. Almost went with the Rough Country online unit, but dreaded the thought of having to remove so many panels to install it. Glad I went this route. Much much easier to install. Just remove one panel and connect to two ports.Vehicle install:First hookup was a little tough because of positioning of the green ports under dash. Had to partially remove the panel under steering wheel. Cable length was sufficient to get the job done. Device booted up and recognized my VIN immediately. I did have to tune a few times to get calibration as close as possible (dash & GPS). Recently upgraded to Radar Renegade 295/65R20 (35.1”) tires. Initial variance was 5-6 mph over speedometer reading. After a few tunes, I settled on a tune of 34.75” with only a sporadic 1 mph under speedometer reading variance while driving 50 mph. Close enough for me. Measuring the actual tire height made dialing in the initial settings to start with very helpful. Really like that the unit checks for DTCs and allow you to save settings with custom labels.Overall:Will report back after testing at higher speeds. Shifting is drastically better now. Will just have to remember to return to stock settings before servicing truck at a dealership.Fuel economy update:Extremely pleased to note that I am back to 16+ mpg since lift and 35s because of this calibration tool. Haven’t had any issues described by other reviewers. Will circle back around if anything changes. All good so far.

Followed all instructions completely. Was able to get it to check for latest firmware updates on my computer and it verified that it had the most current version. However, when plugged into the truck it would only show "looking for computer" and never anything beyond that. According to the instructions, that's not even one of the things it should say when plugged into the truck (not the computer). Have used these products before on a Jeep Wrangler and always had good success. This one, however, didn't work at all on my 2019 RAM 1500 Limited.

This is just what you need to recalibrate your speedometer when changing the tire size on your truck. FYI this does work with Windows 11. If you get an error code the unit will need to be connected to a Windows based PC to be updated. I was glad mine didn't need to be updated since I only have Apple computers.

This product will VIN lock to the first vehicle it tunes. The only way to restore it is to connect to original vehicle and return that vehicle to stock settings. I learned the hard way thinking I was getting a good price. Quick google search of the error message revealed what was going on. Pay extra and save the headache. And wait time. There’s no two-day prime delivery on these.

I have a 2019 Ram 1500 5.7.I installed larger tires, going from 275/55/20 Falken to Michelin 275/65/20 Ltx AT/2 E load. I had a speedometer difference of about 4 mph. After reading many reviews & forums I ordered the Hypertech 3400 from Amazon. It seems some folks had issues in the past with larger tire size calibration messing up the park assist or park sensors. I believe that those instances usually involved larger tires than what I installed. It didn't affect my park sensors or anything else. The Hypertech 3400 was straight forward and simple. I updated it on my laptop to ensure it had the most up-to-date info, and once hooked up to my truck, it took 10 min. or less to program. Using 33.50 as the tire size, my speedometer is spot on now, with no issues whatsoever. I can easily plug it in and switch back to stock parameters if I need to take it in to the dealership for service. Simple, easy, does what it should.

With the new OBDII ports, Ram installs a gateway, so you need to connect to the CANBUS bar, which isn't a big deal. When attempting to correct for the new tire size, the unit fails and says "low voltage", which isn't factual. I pulled as many fuses as I could to reduce any load, but nothing worked to include adding a jump box.I called the Tech line and they tried to help, but the unit isn't well designed and should never fault for low voltage when the voltage is fine.Returned for a refund.

I bought this to recalibrate my speedometer on my jeep. The benefit to buying this is if you go with a different size tire or re gear then you don’t have to go to the dealership and pay stupid dealership money to do the same thing

I purchased the Hypertech 3400 s/n 2118497 off Amazon for my 2020 Jeep Gladiator w/ 3.6L gas. Its a Rubicon and comes with 33" tires. I put 35" tires on but cant get it to calibrate correctly. I checked my speed before calibrating and the Jeep said 60 when apps on my phone said 65, so it was reading 5 MPH slow (as expected). Tires on the jeep actually measure 33.75 so Hooked up device and input the info (stereo, lights etc off) then ran a test and now it reads 4 MPH fast. Tried inputing 35" and is off 6 MPH. Put in 33" (smaller that actual tire) and its off 3.5 - 4 MPH. Im super frustrated. I updated it online, and tried again, same results. Ready tp take a hammer to this thing. What do I do? I feel like I wasted my money on this thing. I Wrote customer support and they said “ Go down on the new tire size to play with the numbers ” which I’m going to do but it just seems this device should be more accurate. Had I known that I would face these issues to begin with I would’ve stepped up and bought something else.