SCT X4 Review – 2021 Complete Guide

| Last Updated: June 26, 2021

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When a vehicle leaves the factory, its computer is programmed with a generalized tune that is designed for the masses. Obviously, the entire line is calibrated to an average driver's needs, not a performance enthusiast. So we find people often complaining about a mediocre driving experience.

If you are sick and tired of this frustrating performance, you should really look into getting a tuner installed on your vehicle. As a performance enthusiast, you will need an efficient unit that can help you optimize engine performance as well as allow speedometer correction, diagnostics, gauge monitor, etc. To simplify the matters for you, we have a perfect candidate for you to pick up the SCT X4. 

This article is a detailed review of SCT X4. If you are interested in purchasing a tuner, we highly recommend that you read this till the end as you will gain sufficient knowledge to help understand why it is such a great choice.  

  • Comes with a built-in Wi-Fi connection
  • Has a large display for easy reading
  • Will provide a massive power improvement
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  • Supplied as a complete kit
  • Highly suitable for towing vehicles
  • One of the most versatile units you can get
  • User-friendly interface is easy to navigate through
  • Has the capacity to save ten different tunes at any time


  • Custom tunes cost extra
  • Display lacks a touchscreen interface

Specs and Dimensions

  • Manufacturer: SCT Performance

  • Brand: SCT

  • Item Weight: 1.05 pounds

  • Length: 12.6 inches

  • Width: 9 inches

  • Height: 2.25 inches

  • Type: Hand-held

  • Display: Full color

  • Fuel type: Gas/Diesel 

  • Battery: No

  • OBD2 Cable: Included 

  • Wi-Fi: Yes (built-in)

  • Memory size: 4GB

  • Number of Custom tunes held: 10

  • Number of unlocks allowed: 5

  • Connectivity Cable: Included

  • Mount: Not Included

Main Features

  • One of the most simple and easy-to-use programmers on the market

  • Comes pre-loaded with DYNO proven tunes

  • Installation on the vehicle is a breeze

  • Can hold up to ten custom tunes

  • Allows you to tweak numerous PCM settings

The SCT X4 allows you to take complete control of your vehicle and its performance. It is a hand-held unit with a sleek design and quality hardware components. Unlike many other tuners available on the market, this one is very simple and easy to program and use. It does not operate on a battery. Just connect it to the vehicle via the OBD2 adapter cable, and it is ready to use. 

It is capable of functioning out of the box. The reason here is that it is preloaded with some DYNO proven tunes. These tunes are specially designed to increase the stock horsepower and torque. However, if you are not satisfied with their optimization, you can always download custom tunes that are specially designed to cater to the individual needs of different drivers and their vehicles. 

One more aspect that makes X4 stand out from the rest is its ability to unlock itself five times before finally locking on the last vehicle permanently. It is not a common feature as most tuners are designed to read the VIN and lock themselves on to the vehicle only once. You cannot use them on any other vehicle before having it unlocked for a high fee.


The SCT X4 makes for a great investment for a number of reasons. These include:

One of the Most Versatile Units You Can Get

The X4 is designed to be a versatile product. It is not only effective in tuning the engine for a more powerful and efficient performance, but it also serves a number of other useful purposes too. 

It is perfectly capable of recording and displaying real-time engine performance data. It improves torque, saves you some money with its fuel-efficiency, delivers a smoother and turbulence-free ride, and optimizes different PCM parameters to suit your requirements, amongst other things. 

Furthermore, it can reduce the frequency of your trips to the repair shop by helping you diagnose and solve the engine issues yourself. 

Has the Capacity to Save Ten Different Tunes at Any Time

This programmer is great at storing custom tunes. With 4GB of built-in memory, it can store up to ten tunes at any one time. This feature is highly useful as you can get it to address your various driving needs with a specially customized tune for that purpose. 

For example, you can store one for towing, and another one for street use. Different driving scenarios call for different engine settings, so having a variety of tunes to keep up with your demands is a huge advantage. 

Highly Suitable for Towing Vehicles

Drivers of towing vehicles know how tough it is to drive such vehicles. Not only do they have to handle their own vehicle, but they also need to keep an eye on the requirements of the trailer, camper, or any other vehicle towing behind them. 

The X4 is great at maintaining a consistently smooth ride. With a tune customized for towing needs, you can completely rely on it for superior and efficient performance. 

Supplied as a Complete Kit

It is also good to know that SCT is supplying its best-selling X4 programmer as a complete kit. Since this hand-held unit does not operate on battery, an OBD2 cable is a must. The package includes both the OBD2 adapter cable as well as the Micro USB Cable to save you from making additional purchases. 

Note that the pack does not include a mount. SCT designed it to be used as a hand-held device, so the lack of a mount makes sense. 

User-friendly Interface is Easy to Navigate Through

This device is designed to be a hand-held unit. It has a very user-friendly interface, so it does not have any confusing dials or buttons. Instead, there are four arrow buttons with a selection one in the middle. They are not hard to press and respond to the slightest touch. 

The screen is good in size with a back-lit full-color display. This makes it easy to read. The main menu layout is very simple and easy to navigate through as well. Just like a smartphone, you can easily operate it with a single hand. 


Despite the plethora of benefits, the SCT X4 doesn’t come without its fair share of drawbacks. These include:

Custom Tunes Cost Extra

The device comes with some pre-installed canned tunes. But if you are not satisfied with any of them, you can have a dealer design a custom tune for you. Though, you should know that having a custom tune made can cost you anywhere from $50 to a couple hundred and sometimes even more. So if you are thinking of having a tune designed for your specific use, keep in mind the additional cost that you will have to pay before you are able to use it with your SCT X4. 

Display Lacks a Touchscreen Interface

Like we said above, this tuner features an extremely user-friendly interface. Yet we think that had it been equipped with a touchscreen, the end result may have been much better. Touchscreens are the go-to these days. Similar to any smartphone, this device is meant to be hand-held, so having a touchscreen would have made it easier to use. 

What Can the SCT X4 Do For Me?

The SCT X4 is a surefire way of increasing the efficiency of your vehicle. But that is not the only thing it can do. It can serve you in more than one way. Let’s see what it can do for you. 

Display Data

The SCT X4 features an easy-to-read screen that displays all the real-time driving performance data. It helps you keep an eye on speed, spark, coolants, pressure, and torque, amongst other things. You can also customize it to choose the parameters you want it to display. 

Diagnose and Troubleshoot

This is one useful task it does for you. You may all be familiar with the feeling of dread and frustration on seeing the ‘check engine’ light flash. Normally, you cannot understand the messages your vehicle is trying to convey. However, an X4 is perfectly apt at reading and conveying the problem to you. You can then use this information to address the issue and troubleshoot it on your own. 

Customize Settings

The X4 not only allows you to download canned and custom tunes to your vehicle, but it also allows you to customize the entire PCM according to your requirements. Since everybody has a different driving style, having this freedom allows you to enjoy your drive to the fullest. 

Increase Power

Tuners are well-known for increasing the torque and power of any vehicle, and the SCT X4 is no different. It is an expertly designed unit regulating and optimizing the PCM to deliver a smooth and powerful performance, unlike any you have ever experienced.

What Do I Need To Know Before Buying a SCT X4?

Purchasing the SCT X4 is a relatively big investment. You don’t want your money to go down the drain. Therefore, it is better to research thoroughly before finalizing it. This way, you will be making an informed decision that is less likely to backfire. Here are some things you need to know before buying an SCT X4. 


Checking your vehicle’s compatibility with the X4 should be your number one priority. You don’t want to go through the hassle to find out that it is unable to tune your vehicle. It is best suited for all Ford trucks and cars that were manufactured between 1996 and 2014. Remember, it is not compatible with all Ford models. 

Enhance Performance

All the tuners manufactured to this date enhance your engine’s performance in one way or another. Since you are reading an article reviewing the SCT X4, chances are you are already aware of this fact. So when you head out to purchase one, remember that it will unleash the sheer raw power of your vehicle. 

Versatile Performance 

You should know that the SCT X4 is one of the most comprehensive tuners. Other than recording and displaying the data of nearly every parameter of engine performance, it can also read error codes. This way, it not only helps you diagnose any problem your vehicle might be having, but it also allows you to fix it without having to visit a repair shop. 


While we will always advise you to purchase a brand new unit if you happen to find a used unit that might get you interested in buying, be sure to check its status. It can either be locked or unlocked.

A locked unit can’t be used to tune any vehicle unless it is unlocked first. The X4 can be unlocked five times before it is permanently locked, after which it needs to be sent to the manufacturer to unlock for a fee of around $150.

Comparison Overview

Tuners are a complete game-changer when it comes to driving and operating a vehicle. If you don’t own one yet, you are really missing out. SCT is a known and respected brand in the world of automotive performance tuners, and the X series is their best-selling yet. The X4 is a relatively new addition to this range. Let's see how it compares to some of the other units available on the market. 

SCT BDX vs. X4

Since the same company manufactures both BDX and X4, you might think that they are similar. We agree that it is true to some extent, but there are some differences as well that make them stand out from each other. Let’s take a look at their similarities and differences. 


As stated above, the first obvious similarity is the manufacturer. SCT develops both. They can each download ten tunes, are great at optimizing vehicles, and the hardware looks more or less the same. The screen size is equal, and both devices can also update themselves over Wi-Fi. 


The first thing we noticed is that the packaging is different. The overall appearance is also different. While the BDX may look more attractive in pictures, it is somewhat blocky to hold in reality. Also, the BDX locks itself to only one vehicle, and you will have to pay an unlocking fee to be able to use it on another vehicle. The X4 is better in this regard as it can unlock itself from different vehicles five times before permanently locking itself. 

SCT X4 vs. Livewire TS+

Livewire TS+ is another one of SCT’s performance programmers. It is also a popular choice amongst the vehicle-tuning community. Here’s how it compares to the best-selling X4. 


Being manufactured by SCT, both X4 and Livewire TS+ are constructed with high-quality components. You can really trust them to unleash your vehicle from factory presets and bring out its real potential. You can load up to ten tunes on either of them. They not only optimize engine performance but also help you diagnose and troubleshoot engine problems. 


X4 and Livewire TS+ look way different from each other. While the former is a hand-held device that features an easy-to-read screen, the latter features a full-color touchscreen with a dash mounting design.

The X4 needs PC software for data logging. TS+, on the other hand, saves the data onto itself for faster and easier logging. It also offers a backup rear camera view as an added safety feature.

How to Use an SCT X4

Whether you drive a luxury car or a powerful truck, having an SCT X4 tuning it will greatly improve its performance. It offers numerous adjustments for the complicated engine processes, yet the device itself is very easy to install and use. Here’s how you can use the SCT X4 to optimize the performance of your vehicle. 

  1. Start by unboxing the device. 

  2. Mount it at a suitable position near the steering wheel. 

  3. Take the OBD2 adapter cable and connect it to the diagnostic port located on the steering wheel column.

  4. Take the plug end of the cable and connect it to the HDMI port on the tuner. This will power it up. 

  5. Once the device is on, turn the key to the on position. 

  6. Press and hold the start engine button for two to three seconds. 

  7. Select continue and let it process the data. 

  8. Now go to the main menu and select the Program vehicle option. 

  9. Select continue when presented with the street use notice. 

  10. It will present you with vehicle options. Arrow over and select the vehicle you want to program it for. 

  11. If you have any custom tunes installed, you can choose to upload it now. 

  12. If you don’t have any custom tunes, you can access the adjustments menu. 

  13. Go over each setting and optimize the settings according to your driving needs.

  14. Once you have adjusted all the parameters, you can go on and approve it. 

  15. The device will present you with a list of settings that you chose. If it looks okay, select continue. 

  16. Next, you will be asked to cycle the key between on and off while it saves the stock settings first and then modifies the PMC according to your adjustments. 

  17. Wait for the download to complete.
  18. Return the key to off one last time, and you are done.

  19. You can also choose the parameters you want your tuner to display from the gauges menu.

We know that the process seems tough and time-consuming but trust us, it’s not. Here’s a video that you can use for additional help. 

How to Unlock an SCT X4 Tuner Yourself

While the internet might twist everything up to tell you that you really cannot unlock an SCT X4 Tuner yourself, not only can you do it yourself, but the process is very simple too. All you need is the programmer, the vehicle it is locked onto, and the adapter plug cable. 

SCT has enabled their X4 to unlock five times before it permanently locks itself. Only in this situation will you need to contact them for unlocking and pay a hefty fee for the service. Here’s how you can do it most of the time: 

  1. Take the adapter plug cable and connect it to the diagnostic port located beneath the steering wheel column. This will power up the device. 

  2. The first option in the main menu is Program Vehicle. Select it. 

  3. You will be presented with a street use notice with three options beneath it. Select Return Stock. 

  4. Once the command is processed, the device will prompt you to turn the key to the on position. Do it and select continue. 

  5. You will be asked to confirm returning to stock settings. Arrow over and select continue.

  6. The tuner will start unlocking itself from the vehicle. 

  7. After unlocking, it will start writing the stock settings on the PCM. 

  8. Once the download is complete, you can return the key to off, and the device is unlocked from the vehicle.

The process is actually pretty simple. If you still seem to face any difficulties, check out the video provided below to better understand the method. 


SCT X4 is a clean and easy way to unleash the full potential of your vehicle. It allows you to gain power on a late model vehicle. Regardless of their skill level, anybody can tune their vehicle according to their driving needs with this unit. It can store up to ten different tunes. And if you are not satisfied with the pre-loaded tunes, you can always get a custom tune made that is tailored according to your needs. 

Other than this, it can detect all the strange error codes the engine might be throwing at you with the ‘check engine’ sign lighting up. When you can identify the problem, you can take care of it yourself too. Hence, the SCT X4 is not only efficient but useful too. 

People Also Ask

Finalizing your choice of a tuner is a daunting task. It is further complicated by the multitude of products dotting the market, each claiming to be the best. The SCT X4 is undoubtedly a quality unit that certainly lives up to its hype. We have rounded up a few questions that might be plaguing your mind to help you understand better. 

Is the SCT X4 Worth it?

If you want to get the most out of your engine’s performance, an SCT X4 is definitely a worthy investment. We know that the upfront cost is a bit high, but rest assured, it will save you that much money, and even more, with its efficiency. Whether you own a gas or diesel-powered vehicle, once you start tuning it with the X4, you will notice an instant improvement in the overall performance. 

How to Get Custom Tunes For SCT X4

SCT has thousands of custom tuning dealers operating all over the world. If the X4 is not preloaded with a tune suitable for your vehicle, you can hire their services. They will work remotely with you online to create a custom tune for you and send the files to you via email. Once you have the files, you can access them in the SCT Device Updater Software on your PC. Using the provided USB cable, connect your X4 to the PC and download the tuner's custom tune files. 

How Do I Factory Reset My SCT X4?

SCT allows their X4 tuners to unlock five times before they are permanently locked to the vehicle. Here is how you can factory reset your SCT X4. 

  1.  Power up your SCT X4. 

  2. Open the main menu and select ‘Program Vehicle.’ 

  3. Scroll all the way down and select the ‘Return to stock' option. 

  4. When prompted, turn the key to the on position to initiate flashing. 

  5. Press continue to confirm the return to stock settings. 

  6. The tuner will start restoring PCM settings back to stock. 

  7. Throughout the process, you will be asked to cycle the key between on and off positions. Follow the directions. 

  8. Once the loading has completed, your vehicle will revert back to its original factory tune.

What Tunes Come With SCT X4?

The SCT X4 can be loaded with up to ten tunes, some of which are preloaded. For a gasoline engine, you get octane and economy tunes, while for the diesel engines, there are three preloaded tunes: performance, towing, and street. You can also load it up with tunes that are customized according to your usage and the conditions in which you drive. 

What Types of Vehicles Will a SCT X4 Work On?

Though it works well with any vehicle, the SCT X4 is highly compatible with Ford cars and trucks manufactured between 1996 and 2014. Regardless of them using gas or diesel as fuel, the unit does an exceptionally good job of optimizing their engines for overall better performance. 

How Much HP Does SCT X4 Add?

The X4 is SCT’s handheld automotive performance product. It is very well-known for increasing the vehicle’s horsepower, torque, and throttle response by optimizing PCM. Depending on your vehicle's make, usage, and fuel, the SCT X4 installed in your vehicle can increase its power anywhere from 11 HP to 120 HP. 

Can SCT X4 Be Used on Multiple Vehicles?

Yes, SCT X4 can be used on multiple vehicles, but it can only tune one vehicle at a time. Once you load it on an automobile, it will lock itself on to it. In order to use the same unit on a different vehicle, you have to first return the vehicle to stock settings to unlock the tuner from it. Only then can you use it on another one. Also, remember that it can unlock five times, after which it will lock itself permanently. 

Sean comes from the forums actually and drives an OBS Ford. He writes fantastic DIYs and knows his way around a camera, too. We keep him caffeinated and away from DPF filters to avoid another rant about recent emissions restrictions.