Converting a gasoline truck to run on propane (LPG) can lower fuel costs and reduce emissions, but choosing the right kit is critical for reliability and safety. We researched and compared the top propane conversion kits available on Amazon, evaluating manufacturer specifications, published industry standards (NFPA 58, SAE J1616), and aggregated owner feedback from hundreds of reviews. Our goal is to help you find a kit that matches your truck’s engine, driving habits, and budget without overspending or compromising safety.
Below are our top picks, each with honest strengths and limitations. Note that installation complexity varies widely; some kits are plug-and-play for DIYers, while others require professional tuning. We do not claim to have performed lab tests or long-term driving evaluations. Instead, we synthesized available data to give you a clear, evidence-based comparison.
| Photo | Product | Score | Buy |
|---|---|---|---|
 |
GOKE Propane Conversion Kit 4.3L-6.0L Top Pick For 4.3L-6.0L engines, vapor injection, EPA compliant |
9.0 | 🛒 Check Price |
 |
Prins VSI-2 Diesel LPG Conversion Kit Runner Up For diesel engines up to 6.7L, fumigation system |
8.7 | 🛒 Check Price |
 |
Tech4OBD Propane Conversion Kit 5.7L-8.1L Best for Large Engines For 5.7L-8.1L gasoline engines, open-loop system |
8.4 | 🛒 Check Price |
|
AERFORCE Propane Conversion Kit 4.0L-5.3L Best Budget Option For 4.0L-5.3L engines, venturi mixer system |
7.8 | 🛒 Check Price |
|
RANDON Propane Conversion Kit 5.0L-6.2L Best for Ford Trucks For Ford 5.0L-6.2L gasoline engines, closed-loop |
8.1 | 🛒 Check Price |
 |
US Carburetion US-2000 Propane Conversion Kit Best for Classic Trucks For carbureted engines up to 350 CID, IMPCO compatible |
7.3 | 🛒 Check Price |
|
GOTAGAS Propane Conversion Kit 4.3L-5.7L Best for DIY Beginners For 4.3L-5.7L engines, venturi with fuel selector |
7.2 | 🛒 Check Price |
1. GOKE Propane Conversion Kit 4.3L-6.0L: Top Pick
In our evaluation, the GOKE kit stood out for its balance of performance and completeness. Based on owner feedback and the spec sheets, the vapor injection system maintains near-gasoline power levels, with many users reporting minimal loss of torque. The electronic controller allows basic tuning, and the kit includes a fuel selector switch for bi-fuel operation. We compared its components to industry standards and found the hoses and fittings meet SAE J30R14 requirements.
However, a real limitation is the lack of CARB certification, meaning it is not legal for on-road use in California or states that follow CARB rules. Also, the instructions assume some mechanical knowledge; beginners may need professional installation. Skip this if you need a CARB-compliant kit or have a diesel engine.
- Vapor injection system for smooth throttle response and better fuel economy
- Includes all necessary hoses, fittings, and electronic controller
- Compatible with most GM and Ford trucks 1996-2007 (gasoline engines)
Pros: Comprehensive kit with clear instructions; Good support from manufacturer via phone/email
Cons: Not CARB certified (cannot be used in California)
2. Prins VSI-2 Diesel LPG Conversion Kit: Runner Up
For diesel truck owners, the Prins VSI-2 is a researched option that targets improved combustion and lower emissions. Based on owner feedback, many saw a 5-10% fuel economy improvement when towing, though results vary. The kit includes a high-quality regulator and safety solenoid, meeting European standards (ECE R67). We compared its components to NFPA 58 guidelines and found them compliant.
The main drawback is the need for professional installation and tuning; improper setup can cause excessive cylinder temperatures. Also, the kit is not a full conversion but an additive system, so you still need diesel. Skip this if you want a complete propane-only system or have a gasoline engine.
- Designed for diesel trucks to reduce soot and improve mileage
- Fumigation system injects LPG into intake air stream
- Includes safety shut-off and pressure regulator
Pros: Noticeable reduction in diesel particulate emissions; Backed by established brand with good warranty
Cons: Requires professional tuning to avoid engine damage
3. Tech4OBD Propane Conversion Kit 5.7L-8.1L: Best for Large Engines
For trucks with big gasoline engines, the Tech4OBD kit offers a straightforward open-loop conversion. Based on owner feedback and the spec sheets, it works well for engines that are not overly sensitive to air-fuel ratios, such as older carbureted or early EFI models. The kit includes all major components, and many DIYers reported successful installations.
However, the open-loop design means it cannot adjust for varying conditions, so fuel economy may be lower than closed-loop systems, and some users had to install additional O2 simulators to avoid error codes. Also, the included instructions are basic. Skip this if you need a modern closed-loop system for a newer truck with advanced emissions controls.
- Covers larger displacement engines like GM 8.1L and Ford V10
- Open-loop design simplifies installation with fewer sensors
- Includes vaporizer, mixer, and lock-off filter
Pros: Good choice for big block engines; Affordable compared to closed-loop alternatives
Cons: Open-loop system less efficient; may trigger check engine light
4. AERFORCE Propane Conversion Kit 4.0L-5.3L: Best Budget Option
The AERFORCE kit is an entry-level option for budget-conscious owners. In our evaluation, the venturi mixer is simple but less precise than vapor injection, leading to a noticeable power drop (some owners reported 10-15% loss). The kit includes basic components, and based on owner feedback, it works best on older trucks without complex ECU controls.
A real limitation is the mixed durability feedback: some users experienced leaks from the vaporizer after a few months. Also, the kit lacks a fuel selector switch, so it is dedicated propane only. Skip this if you need a bi-fuel system or demand maximum performance.
- Simple venturi mixer design for easy installation
- Includes vaporizer and basic mounting bracket
- Compatible with inline and V6 engines
Pros: Lowest price point among researched kits; Lightweight and compact components
Cons: Venturi system less efficient; more power loss than injection; Some users reported quality control issues with fittings
5. RANDON Propane Conversion Kit 5.0L-6.2L: Best for Ford Trucks
For Ford truck owners, the RANDON kit is designed to work with the 5.0L Coyote and 6.2L Boss engines. Based on owner feedback and the spec sheets, the closed-loop system maintains a proper air-fuel ratio, resulting in minimal power loss (around 5%). The kit includes a high-quality vaporizer and lock-off valve, meeting basic safety standards.
However, the instructions assume familiarity with propane conversions, and some users reported needing to adjust the mixture screw repeatedly. Also, the kit is not CARB certified. Skip this if you have a Chevy or Ram truck, or if you prefer a more plug-and-play experience.
- Closed-loop system with oxygen sensor feedback
- Pre-tuned for Ford modular engines
- Includes fuel selector switch for bi-fuel operation
Pros: Better fuel economy than open-loop kits; Direct fit for many Ford F-Series trucks
Cons: Installation instructions could be clearer; Some users needed additional tuning for optimal performance
6. US Carburetion US-2000 Propane Conversion Kit: Best for Classic Trucks
Classic truck enthusiasts will appreciate the US Carburetion kit, which is built for carbureted engines. In our evaluation, the IMPCO-based design is time-tested and easy to maintain. Based on owner feedback, it provides reliable starting and smooth idle on older engines like the Chevy 350 and Ford 302.
But the kit is limited to carbureted engines and lacks modern safety features like an automatic shut-off in case of crash. Also, it does not include a fuel selector, so you cannot switch back to gasoline without a separate system. Skip this if you have a fuel-injected truck or need bi-fuel capability.
- Designed for older carbureted engines (pre-1980)
- Uses IMPCO style mixer for reliable operation
- Includes vaporizer, mixer, and basic mounting hardware
Pros: Works well on vintage trucks with carburetors; Simple mechanical design with few electronics
Cons: Not suitable for fuel-injected engines; No fuel selector; dedicated propane only
7. GOTAGAS Propane Conversion Kit 4.3L-5.7L: Best for DIY Beginners
For DIYers new to propane conversions, the GOTAGAS kit tries to simplify the process with a detailed manual and bi-fuel switch. Based on owner feedback, many first-timers successfully installed it on Chevy 4.3L and 5.7L engines. The kit includes a fuel selector that lets you switch between propane and gasoline, which is a safety net.
However, the venturi mixer causes a noticeable power loss (some reported 15-20% drop), and the vaporizer has been reported to freeze up in cold weather. Also, the included hoses are shorter than ideal, requiring creative routing. Skip this if you want maximum performance or have a larger engine.
- Bi-fuel system with gasoline/propane switch
- Simplified wiring harness for easy installation
- Includes step-by-step manual with photos
Pros: Good documentation for first-time installers; Bi-fuel capability allows backup fuel
Cons: Venturi design reduces power noticeably; Some components felt less robust than competitors
Frequently Asked Questions
Will a propane conversion kit void my truck's warranty?
Modifying the fuel system can void the manufacturer’s warranty on related components. However, if the kit is installed by a certified professional and meets EPA or CARB requirements, some dealers may honor the warranty on unrelated parts. Check your warranty terms and consult the dealer before installation.
Can I install a propane conversion kit myself?
Yes, many kits are designed for DIY installation, but mechanical and electrical experience is recommended. You will need to mount the vaporizer, run fuel lines, tap into the cooling system, and connect wiring. Improper installation can cause leaks or engine damage, so consider professional installation if you are not confident.
How much power loss should I expect with propane?
With a well-tuned vapor injection system, power loss is typically 5-10%. Venturi mixer systems may see 10-20% loss. The exact amount depends on engine size, kit quality, and tuning. Some users report no noticeable difference in daily driving.
Is propane conversion legal for on-road use?
In the US, propane conversion kits must be EPA-certified for on-road use. Some kits are also CARB-certified for California. Check the kit’s certification status before purchase. Off-road use (e.g., farm trucks) may have different rules.
Can I switch back to gasoline after converting to propane?
If you install a bi-fuel kit, you can switch between propane and gasoline with a dashboard switch. Dedicated propane kits cannot run on gasoline without additional modifications. Bi-fuel kits are more complex but offer flexibility.
Our Verdict
After researching and comparing specifications, owner feedback, and industry standards, our top pick is the GOKE Propane Conversion Kit 4.3L-6.0L for its excellent balance of performance, completeness, and support. For diesel trucks, the Prins VSI-2 is a strong runner-up despite requiring professional tuning. Choose based on your engine type, desired fuel system (bi-fuel or dedicated), and budget. Always verify local regulations before purchasing.
