If you flat-tow a vehicle behind your motorhome, you have likely had the uneasy thought on a long downhill grade: all that extra weight pushing from behind is relying entirely on the motorhome's brakes to stop. A supplemental braking system fixes that, applying the towed vehicle's own brakes in concert with the coach, and in many places, it is not just smart but legally required.
Two names dominate the conversation when RVers shop for one: Brake Buddy and RVi. Both are portable systems that sit in the towed vehicle and apply its brakes when you slow the motorhome, and both have earned loyal followings. But they take somewhat different approaches, and the right one depends on how you tow and what you value.
Getting this choice right matters more than most towing decisions, because it is fundamentally about safety, your stopping distance, your control on grades, and the wear you put on the motorhome's brakes. A good supplemental brake makes the whole rig stop shorter and tow safer, and protects an expensive coach braking system in the bargain.
In this guide, I will compare Brake Buddy and RVi head-to-head, explain where each shines, and point you to the specific systems to consider, so you can flat-tow with the confidence that everything behind you is helping to stop.
Before comparing the two, it is worth being clear on what a supplemental braking system actually does and why it is so important. When you flat-tow, or tow four-down, the towed vehicle rolls on all four wheels behind the motorhome, adding thousands of pounds that the coach must stop on its own unless the towed vehicle helps.
A supplemental braking system senses when the motorhome is slowing or stopping and applies the towed vehicle's brakes in response, so the whole combination stops as a coordinated unit. This shortens stopping distances dramatically, improves control on steep descents, and reduces the heavy strain that towing otherwise places on the motorhome's brakes.
There is a legal dimension too. Many states and provinces require supplemental braking on towed vehicles above a certain weight, so a system is often not optional but mandatory. Beyond the law, it is simply one of the most important safety investments a flat-towing RVer can make, which is exactly why choosing the right one deserves real thought.
It is worth appreciating just how much load a towed vehicle adds. A typical flat-towed car can weigh several thousand pounds, and asking the motorhome alone to stop all of that, especially repeatedly on a long mountain descent, generates real heat and wear in the coach's braking system. A supplemental brake distributes that work to the towed vehicle's own brakes, where it belongs, which is why it protects the motorhome's brakes as much as it shortens your stopping distance.
Both Brake Buddy and RVi are known for portable supplemental braking systems, units that sit in the towed vehicle and can be moved between vehicles, rather than being permanently installed in one car. This portability is a major part of their appeal, since it means the system can follow you if you change towed vehicles.
The general principle is shared: each system applies the towed vehicle's brake pedal in proportion to the motorhome's braking, using its own sensing to decide when and how hard to brake. Where they differ is in the details of how they sense braking, how they are set up, and the specific features and feel each delivers, which is where personal preference and towing style come in.
Here are the two systems to consider, one from each brand, both portable and both proven in the flat-towing world.
It is worth noting that both brands have built their reputations specifically in the towing and supplemental braking world rather than being generalists, which is part of why RVers trust them. When you are dealing with something as safety-critical as bringing a multi-ton combination to a stop, that focused expertise on both sides of the comparison is genuinely reassuring, and it means you are choosing between two specialists rather than gambling on an unproven product.
The Brake Buddy Vantage Select II is a portable supplemental braking system that sits in the towed vehicle and applies its brakes in coordination with the motorhome. Brake Buddy is one of the most established names in supplemental braking, and the portable Vantage Select II carries that long track record.
The portable design means the unit is placed in the towed vehicle for towing and can be removed and moved to another vehicle if you change what you tow. For flat-towers who value a proven, well-known system from a brand with deep experience in supplemental braking, the Vantage Select II is a strong, confidence-inspiring choice.
Buy Brake Buddy Vantage Select II Braking System
The RVibrake 4 is RVi's portable flat-tow braking system, applying the towed vehicle's brakes in concert with the motorhome. RVi built its reputation specifically in the flat-towing braking space, and the RVibrake 4 represents the latest evolution of that focus.
Like its rival, it is a portable unit that goes in the towed vehicle and can move between vehicles, offering the same flexibility for owners who may change their towed car over time. For flat-towers drawn to RVi's dedicated braking expertise and the features of its current-generation system, the RVibrake 4 is the natural pick.
Buy Curt RVibrake 4 Brake Control System
Because both systems are portable units that apply the towed vehicle's brakes, the comparison comes down to the experience of living with them rather than a fundamental difference in purpose. Both must be set in the towed vehicle for each tow, both sense the motorhome's braking and respond, and both deliver the core safety benefit of a coordinated stop.
Setup and daily use are where flat-towers tend to form preferences. A portable system is placed and connected before each trip, so how intuitive that process feels, and how the system communicates with you while towing, shapes the ownership experience. Owners often develop strong loyalty to whichever brand's routine they find most natural.
Portability is a shared strength and an important one. Because neither system is permanently tied to a single vehicle, both protect your investment if you change towed vehicles down the road; the system comes with you. This is a meaningful advantage of choosing a portable unit from either brand over a permanently installed alternative.
Supplemental braking systems generally come in two broad styles: portable units that sit in the towed vehicle and can be moved, and permanently installed systems that are built into a specific vehicle. Both Brake Buddy and RVi are well known for the portable approach, and understanding why that matters helps explain their shared appeal.
A portable system's great advantage is flexibility. Because it is not permanently wired and mounted into one car, it can be removed and placed in a different towed vehicle if you change what you tow, which protects your investment over the years. RVers who upgrade or change their towed car frequently especially value not having to buy a whole new braking system each time.
The trade-off, common to portable systems generally, is that they must be set up in the towed vehicle for each tow rather than being permanently ready. For most flat-towers, this becomes a quick, familiar routine, and the flexibility is well worth it. Since both Brake Buddy and RVi embrace the portable approach, you get this flexibility whichever brand you choose, which is part of why these two dominate the conversation.
While the Brake Buddy versus RVi question is the headline, a few practical considerations apply to choosing and using any supplemental braking system, and they are worth weighing alongside the brand decision. The first is your towed vehicle and how the system suits it, since the unit sits inside the vehicle and works with its brake pedal, a good fit with your particular car matters.
The second is the legal requirement for where you travel. Supplemental braking laws vary by state and province, often tied to the towed vehicle's weight, so confirming what is required on your routes ensures you are both safe and compliant. Both Brake Buddy and RVi exist precisely to meet this need, so either satisfies the core requirement, but knowing your obligations helps you choose with confidence.
The third is how the system communicates with you while towing. Many flat-towers value being able to confirm the system is working from the driver's seat, and the monitoring and feedback a system provides is part of the daily ownership experience. This is an area where personal preference between the brands often forms, so if you can, talking to owners of each helps you find the feel you prefer.
Finally, think about the setup routine. Because both are portable, you will place and ready the system before each trip, so a process that feels intuitive to you makes flat towing more pleasant trip after trip. None of these considerations point to one brand over the other universally; rather, they help you match the right system to your vehicle, your routes, and your preferences.
Brake Buddy's long-standing reputation in supplemental braking is its core strength. As one of the most recognized names in the category, it offers the reassurance that comes from a brand many RVers know, trust, and recommend to one another at campgrounds and in flat-towing circles.
The Vantage Select II's portable design delivers the flexibility flat-towers want, sitting in the towed vehicle and moving between vehicles as needed. For owners who prioritize a proven, widely used system with a deep track record behind it, Brake Buddy is a natural and confidence-inspiring choice, and its broad familiarity means plenty of fellow owners to compare notes with.
RVi's strength is its dedicated focus on the flat-tow braking space, and the RVibrake 4 represents the current generation of that specialized development. For owners who want a system from a brand concentrated specifically on towed-vehicle braking, that focus is appealing.
The RVibrake 4 is likewise portable, moving between towed vehicles, so it offers the same investment-protecting flexibility. Flat-towers drawn to RVi's specialization and the refinements of its latest-generation system will find the RVibrake 4 a compelling, purpose-built choice from a brand that lives and breathes supplemental braking.
Both systems deliver the essential safety benefit, and both are portable, so the decision comes down to brand preference, the specific feel and setup you favor, and which fits your towing routine. Here is how to think it through.
You value one of the most established, widely recognized names in supplemental braking and want a proven portable system with a deep track record. The Vantage Select II suits owners who prioritize broad familiarity and the reassurance of a brand many flat-towers already trust and use.
You are drawn to a brand focused specifically on flat-tow braking and want its current-generation portable system. The RVibrake 4 suits owners who value that dedicated specialization and the refinements of RVi's latest design.
Since both systems move between towed vehicles, you are protected if you change what you tow, a real advantage over permanently installed options. This shared strength means whichever brand you choose, your investment follows you to your next vehicle.
Check your towed vehicle's weight against the supplemental braking laws where you travel, and confirm the system suits your vehicle and motorhome setup. Both systems address the same core need, so matching it correctly to your rig and your routes is what matters most.
Whichever you choose, the important thing is that you have a quality supplemental braking system at all. Both Brake Buddy and RVi deliver shorter stops, better control on grades, and reduced wear on your motorhome's brakes, so the safest choice is simply committing to one of these proven systems.
Choosing between Brake Buddy and RVi is, happily, a choice between two capable, proven supplemental braking systems rather than a right-and-wrong decision. Both are portable, both apply your towed vehicle's brakes in coordination with the motorhome, and both deliver the shorter stopping distances, better grade control, and reduced brake wear that make flat towing genuinely safer.
The Brake Buddy Vantage Select II brings the reassurance of one of the most established names in the category, while the RVi RVibrake 4 offers the latest generation from a brand focused specifically on flat-tow braking. Both protect your investment with portability that follows you to your next towed vehicle.
Match the system to your vehicle and your routes, confirm the braking requirements where you travel, and tow with the confidence that everything behind you is helping to stop. That peace of mind on a long downhill grade is exactly what a quality supplemental braking system is for, and either of these delivers it.
One last piece of advice from years of helping flat-towers: do not let the choice between two good systems become a reason to delay. The riskiest setup of all is flat towing with no supplemental braking at all, relying entirely on the motorhome to stop everything. Both Brake Buddy and RVi solve that decisively, so whichever you find yourself leaning toward, the important thing is to get a quality system in place and tow protected.
At RV Upgrades, we carry Brake Buddy, RVi, and a full range of supplemental braking systems and flat-towing gear to keep your towed vehicle stopping safely. Explore our collection and find the right braking system for your setup. Let us help you tow with total peace of mind!
I’m Bill Rowell, the founder of RVupgrades.com. In 2002, I launched the business to help fellow RV enthusiasts find unique and hard-to-find products. Over the years, it’s grown to offer more than 15,000 items, with a warehouse in Eastlake, Ohio. Having owned and repaired nearly every type of RV, I bring over two decades of hands-on experience to the table. For me, this isn’t just a business – it’s a passion and a way of life that I love sharing with the RV community.
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