Which Catalytic Converter Shield Is Better for Your Vehicle?
If you're comparing ADD A CAT vs. MillerCAT, you're already taking an important step toward protecting your vehicle from catalytic converter theft.
Both companies manufacture vehicle-specific catalytic converter shields designed to make accessing and removing a catalytic converter more difficult.
But there are important differences to consider—including materials, security hardware, construction, installation, warranty protection and manufacturer support.
Here's how ADD A CAT by ADD Automotive compares with MillerCAT.
ADD A CAT vs. MillerCAT: Quick Comparison
| FEATURE | ADD A CAT | MILLERCAT |
|---|---|---|
| Vehicle-Specific Design | ✓ Yes | ✓ Yes |
| Material | 3/32" 5052 Marine-Grade Aluminum | Aluminum and/or stainless steel depending on application |
| Security Hardware | Proprietary ADD A CAT Security Bolts + Security Bit | Patented/tamper-resistant security screws on applicable products |
| Construction | One-Piece Design | Varies by application |
| Installation | Bolt-On / No Drilling | Many applications are bolt-on / no-drill |
| Ventilation | Integrated Louvers for Airflow | Varies by application |
| Shipping | Free Nationwide Shipping | Free Ground Shipping to Lower 48 States |
| Houston Installation | FREE with ADD A CAT shield purchase | Installer/dealer options vary |
| Manufacturer Warranty | See ADD Automotive warranty terms | 90-Day Manufacturer's Warranty |
| Theft-Protection Warranty | 1-Year Theft-Protection Warranty | No theft guarantee |
| ADD Automotive Reported Theft Record | 5 Years – No Reported Thefts with a Properly Installed ADD A CAT Shield | — |
Product specifications, vehicle applications and policies can change. Always verify the exact product for your vehicle before purchasing.
Why Choose ADD A CAT?
ADD Automotive didn't design ADD A CAT to simply put a piece of metal underneath your vehicle.
We designed a complete catalytic converter theft-deterrence system.
The ADD A CAT approach combines:
3/32" 5052 marine-grade aluminum
One-piece construction
Proprietary security bolts
Security bit included
Vehicle-specific engineering
Integrated ventilation louvers
Bolt-on installation
No drilling
and something that separates ADD A CAT from many competitors:
A 1-YEAR THEFT-PROTECTION WARRANTY.
3/32" 5052 Marine-Grade Aluminum
Every ADD A CAT catalytic converter shield is manufactured using:
3/32" 5052 MARINE-GRADE ALUMINUM
5052 aluminum provides an excellent combination of:
- Corrosion resistance
- Strength
- Low weight
- Heat dissipation
- Weather resistance
- Long-term durability
ADD Automotive doesn't choose material based solely on thickness.
A catalytic converter shield needs to balance strength, weight, coverage, heat management and mounting integrity.
That's why ADD A CAT uses 5052 marine-grade aluminum.
One-Piece ADD A CAT Design
ADD A CAT shields use a one-piece design engineered around the vehicle.
Why does that matter?
Every unnecessary connection, seam and removable section potentially creates another area that can be attacked.
Our philosophy is simple:
FEWER PIECES.
FEWER WEAK POINTS.
MORE PROTECTION.
ADD A CAT is engineered to create a strong physical barrier between a thief and the catalytic converter.
Proprietary ADD A CAT Security Bolts
The material protecting your catalytic converter is only part of the equation.
The hardware securing that material to the vehicle matters too.
That's why ADD Automotive uses its own:
PROPRIETARY SECURITY BOLT FASTENERS.
ADD A CAT kits include the corresponding security bit required for installation.
The objective is simple:
Make removing the shield another obstacle a catalytic converter thief has to overcome.
Bolt-On Installation — No Drilling
ADD A CAT shields are engineered specifically for the vehicles they protect.
That allows our designs to utilize factory mounting locations whenever possible.
NO DRILLING.
NO WELDING.
COMPLETE BOLT-ON INSTALLATION.
Vehicle-specific engineering also helps provide proper coverage without unnecessary permanent modification to the vehicle.
Designed for Airflow
Catalytic converters operate at extremely high temperatures.
That's why airflow should be considered when designing a catalytic converter shield.
ADD A CAT shields incorporate:
INTEGRATED VENTILATION LOUVERS
The louvers are designed to help maintain airflow while the shield creates a physical barrier around the protected area.
What Does MillerCAT Offer?
MillerCAT is an established manufacturer of catalytic converter protection products.
Depending on the vehicle, MillerCAT currently offers aluminum and stainless-steel Cat Shields.
Many MillerCAT products also feature:
- Vehicle-specific engineering
- Complete bolt-on installation
- No drilling on many applications
- Patented security screws with unique keys
- Aluminum and/or stainless-steel options
- Free ground shipping within the lower 48 states
Certain MillerCAT Toyota applications are also part of Toyota's Associated Accessory Product line.
MillerCAT therefore offers a legitimate catalytic converter theft-deterrence option.
The important question is:
Which protection system gives YOU the features you value most?
ADD A CAT vs. MillerCAT Warranty
This is one of the most important differences to examine.
MillerCAT
MillerCAT currently publishes a:
90-DAY MANUFACTURER'S WARRANTY
According to MillerCAT, its Cat Shield warranty covers manufacturing defects that prevent proper installation or performance, subject to its warranty requirements and exclusions.
MillerCAT also states that its Cat Shields are theft-deterrence devices and does not guarantee its products against catalytic converter theft.
ADD A CAT
ADD Automotive takes a different approach.
Eligible ADD A CAT shields include a:
1-YEAR THEFT-PROTECTION WARRANTY
If your catalytic converter is stolen while an eligible ADD A CAT shield is properly installed, ADD Automotive will refund the shield's purchase price according to the applicable warranty terms and conditions.
That's not simply a manufacturing-defect warranty.
It's ADD Automotive standing behind the theft-deterrence system we designed.
5 Years. No Reported Thefts.
ADD Automotive has been protecting catalytic converters with ADD A CAT shields for approximately five years.
During that period:
ADD AUTOMOTIVE HAS RECEIVED NO REPORTS OF A CATALYTIC CONVERTER BEING STOLEN FROM A VEHICLE WITH AN ADD A CAT SHIELD PROPERLY INSTALLED.
No catalytic converter protection device can make theft physically impossible.
Given enough time, equipment and determination, virtually any anti-theft system can potentially be defeated.
The purpose of ADD A CAT is to make reaching the catalytic converter substantially more difficult, time-consuming and frustrating.
And that's exactly what catalytic converter thieves don't want.
Catalytic Converter Thieves Want Speed
Catalytic converter theft is often about one thing:
SPEED.
A thief doesn't want to spend unnecessary time underneath your vehicle.
A catalytic converter shield introduces another obstacle.
ADD A CAT combines:
Physical coverage
Marine-grade aluminum
One-piece construction
Proprietary security hardware
Vehicle-specific mounting
=
ANOTHER REASON FOR A THIEF TO MOVE ON.
FREE Installation in the Houston Area
Buying a catalytic converter shield is one thing.
Getting it installed is another.
ADD Automotive removes that problem for local customers.
Purchase an eligible ADD A CAT shield and receive:
FREE INSTALLATION IN THE HOUSTON AREA.
Your shield can be installed by the company behind the product.
WE DESIGN IT.
WE MANUFACTURE IT.
WE INSTALL IT.
Appointment required.
ADD A CAT vs. MillerCAT: Which Should You Buy?
MillerCAT offers established catalytic converter protection products, including aluminum and stainless-steel options for numerous vehicles.
But if ADD A CAT is available for your vehicle, consider what you receive:
✓ 3/32" 5052 Marine-Grade Aluminum
✓ One-Piece Design
✓ Proprietary Security Bolts
✓ Security Bit Included
✓ No Drilling
✓ Vehicle-Specific Engineering
✓ Integrated Ventilation Louvers
✓ Free Nationwide Shipping
✓ Free Houston-Area Installation
✓ 1-Year Theft-Protection Warranty
✓ 5 Years With No Reported Theft to ADD Automotive From a Vehicle With a Properly Installed ADD A CAT Shield
That's what we call:
THE ADD A CAT DIFFERENCE.
Frequently Asked Questions
Is ADD A CAT a MillerCAT alternative?
Yes. ADD A CAT is an independent catalytic converter shield manufactured by ADD Automotive and is an alternative to MillerCAT for vehicles supported by both manufacturers.
Is ADD A CAT made from aluminum?
Yes. ADD A CAT shields are manufactured from 3/32" 5052 marine-grade aluminum.
Does MillerCAT make aluminum shields?
Yes. MillerCAT offers aluminum shields for numerous applications and stainless-steel shields for selected vehicles.
Does ADD A CAT require drilling?
No. ADD A CAT shields are designed as bolt-on catalytic converter protection systems using vehicle-specific mounting locations.
Does MillerCAT require drilling?
Many current MillerCAT products are also advertised as complete bolt-on, no-drill installations. Always check the exact application for your vehicle.
Does ADD A CAT use security bolts?
Yes. ADD Automotive uses proprietary ADD A CAT security bolt fasteners, and the appropriate security bit is included with the hardware kit.
Does MillerCAT use security screws?
Yes. MillerCAT advertises patented security screws with unique keys on many of its current Cat Shield applications.
What warranty does MillerCAT offer?
MillerCAT currently publishes a 90-day manufacturer's warranty against manufacturing defects that prevent proper installation or performance, subject to its warranty terms.
Does MillerCAT guarantee against catalytic converter theft?
No. MillerCAT states that its Cat Shields are theft-deterrence devices and that it does not guarantee the product against theft.
Does ADD A CAT have a theft-protection warranty?
Yes. Eligible ADD A CAT shields include ADD Automotive's 1-year theft-protection warranty, subject to the applicable terms and conditions.
Protect It Before They Steal It.
Don't wait until you start your vehicle and discover your catalytic converter is gone.
Put another obstacle between the thief and your catalytic converter.
ADD A CAT
BUILT TO DETER THIEVES.
BUILT BY ADD AUTOMOTIVE.
1-YEAR THEFT-PROTECTION WARRANTY
FREE NATIONWIDE SHIPPING
FREE HOUSTON-AREA INSTALLATION
[SHOP ADD A CAT SHIELDS]
[FIND YOUR VEHICLE]
[LEARN ABOUT THE ADD A CAT DIFFERENCE]
281-608-2894
Catalytic converter shields are theft-deterrence devices. No anti-theft product can guarantee that theft will never occur. Warranty coverage is subject to ADD Automotive's applicable terms, eligibility requirements and conditions.
