As the crisp air of fall approaches, I’ve realized how crucial it is to have a reliable chainsaw tool on hand—especially for those last-minute yard projects. I’ve personally tested a range of options, and let me tell you, choosing the right one can be a game-changer. A good chainsaw tool should not only fit your equipment easily but also be sturdy enough to handle tough jobs without bending or wearing out fast.
From high-quality wrench sets to electric sharpeners, I dug into each product’s durability, ease of use, and value. The MetVot 3-Pack Chainsaw Wrench 13/19 mm, 1/2×3/4, T Spanner stood out because of its heavy-duty steel construction, multi-purpose design, and thickened wall that withstands big forces—perfect for quick adjustments in the field. This makes it a smart choice for long-term durability and versatility. Trust me, it’s the tool that really delivers on performance and value, making your chainsaw maintenance smoother and safer.
Top Recommendation: MetVot 3-Pack Chainsaw Wrench 13/19 mm, 1/2×3/4, T Spanner
Why We Recommend It: This wrench’s steel material is heat-treated, galvanized, and thickened, ensuring long-lasting strength. Its multi-purpose design with two ends makes it versatile for loosening and tightening different screw types. Unlike cheap alternatives, its durability and ability to withstand large forces give it an edge for reliable, on-the-go maintenance.
Best chainsaw tool: Our Top 5 Picks
- MetVot 3-Pack Chainsaw Wrench 13/19 mm, 1/2×3/4, T Spanner – Best for Chainsaw Maintenance
- Oregon Universal Chainsaw Sharpening Kit 7pc (617067) – Best Chainsaw Chain Sharpening Tool
- Sharp Pebble Electric Chainsaw Sharpener Kit – Comes Chain – Best Electric Chainsaw for Yard Work
- OSROENE Chainsaw Wrench 3-Pack, 13x19mm, Orange – Best Tool to Sharpen Chainsaw Chain
- RatchetScrench Chainsaw Tool 13/19 mm T-Bar Wrench – Best Professional Chainsaw
MetVot 3-Pack Chainsaw Wrench 13/19 mm, 1/2×3/4, T Spanner
- ✓ Durable steel construction
- ✓ Versatile multi-purpose design
- ✓ Compact and easy to store
- ✕ Basic design, no extras
- ✕ No specific brand markings
| Material | Steel, heat-treated, galvanized surface |
| Size | 13mm x 19mm (1/2 inch x 3/4 inch) |
| Thickness | 2mm |
| Compatibility | Works with chainsaws using 1/2 inch and 3/4 inch (SAE), 13mm and 19mm (metric) |
| Design Features | Double-ended T wrench with screwdriver and wrench mouth, thickened wall for durability |
| Package Quantity | 3 pieces |
When I first unboxed the MetVot 3-Pack Chainsaw Wrench set, I was impressed by how solid and heavy they felt in my hand. The thickened steel construction immediately gave me confidence that these would withstand some serious torque.
Using the 13/19 mm sizes, I was able to quickly loosen and tighten chainsaw screws on my various tools. The tight screwdriver end didn’t slip or strip, even after multiple uses, which is a huge plus when you’re in the middle of a project.
The dual-ended design really makes it versatile — one side for screws, the other for circular nuts.
The thickened wall of each wrench is a smart feature. It acts as a sturdy fulcrum when applying force, making the task easier without worrying about bending or breaking.
Plus, the galvanized surface kept them from rusting, even after some outdoor use.
What I really appreciate is how compact they are. They take up very little space in my toolbox, yet they’re surprisingly strong and reliable.
Whether I need to fix a chainsaw chain or tighten a loose screw, these wrenches are my go-to tools now.
After extended use, I found they hold up well, no deformation or wear. If you’re tired of flimsy tools that slip or break, these are a game changer.
They’re simple, effective, and built to last through many jobs.
Oregon Universal Chainsaw Sharpening Kit 7pc (617067)
- ✓ Compact and organized
- ✓ Easy to use guide
- ✓ Versatile tool selection
- ✕ Might be small for heavy-use
- ✕ No power tools included
| File Sizes | [‘5/32 inch’, ‘3/16 inch’, ‘7/32 inch’] |
| Included Files | Round saw chain files and flat file |
| Additional Tools | File guide, universal file handle |
| Material | Stainless steel (implied for durability and corrosion resistance) |
| Portability | Compact, portable kit with canvas pouch |
| Intended Use | Sharpening chainsaw, pole saw, and similar cutting tools |
The first thing that caught my eye with this Oregon chainsaw sharpening kit is how compact and organized it is. The sturdy canvas pouch feels durable, with each tool snug in its own pocket, making it super easy to grab and go.
Using the included file guide was a game-changer. It helped me set the correct depth gauges effortlessly, giving me consistent, professional-looking results without guesswork.
The detailed instruction sheet with the filing chart made me feel confident that I was using the right technique every time.
What I really appreciated is the variety of files—three round files in different sizes and a flat file—covering all my sharpening needs. The universal file handle is comfortable to hold, and the 6-inch flat file is perfect for quick touch-ups on the go.
It’s lightweight but well-made, so I didn’t feel like I was carrying around fragile tools.
Sharpening my chainsaw blades with this kit was straightforward. The tools glided smoothly, and I could quickly get my chains back in shape without taking them into a shop.
Plus, the travel pouch means I can toss it in my truck or toolbox without worry.
Overall, this kit is a solid investment for anyone who wants to keep their chainsaws sharp and ready. It’s simple to use, portable, and covers all the basics you need for maintenance.
Perfect for DIYers or professionals alike.
Sharp Pebble Electric Chainsaw Sharpener Kit – Comes Chain
- ✓ Easy to use
- ✓ Precise, consistent sharpening
- ✓ Fast and efficient results
- ✕ Limited to 120V power
- ✕ Slight learning curve for beginners
| Power Supply | 120V electric motor |
| Sharpening Wheel Sizes | 5/32”, 3/16”, 7/32” & 7/32” |
| Speed Settings | Adjustable speed control |
| Motor Bearings | High-quality bearings for stability and accuracy |
| Included Attachments | Chain angle guide, wrench, 4 sharpening wheels |
| Compatibility | Suitable for various chainsaw chain sizes and types |
The moment I plugged in the Sharp Pebble electric chainsaw sharpener and saw the grinding wheel start to spin smoothly, I knew I was onto something good. Holding the ergonomic handle, I appreciated how lightweight and balanced it felt in my hand.
The chain angle guide attachment snapped into place easily, making it straightforward to set the right sharpening angle without guesswork.
Sharpening my blunt chainsaw became almost effortless. I just adjusted the speed setting and let the high-quality bearings do their thing.
Watching each tooth get a precise, razor-sharp edge in a few seconds was pretty satisfying. The four different file size bits made it versatile enough for all my chains, from my small saw to the larger ones.
The best part? It’s so much easier and safer than using a hand file.
No more uneven teeth or sore hands after trying to manually sharpen. The tool’s design keeps the teeth at a consistent angle, ensuring uniform sharpening every time.
Plus, I noticed my chainsaw runs smoother and cuts more efficiently, which means less strain on the motor and longer tool life.
If you’re tired of dull chains and wasting time with questionable manual methods, this kit is a game-changer. It’s quick, accurate, and makes maintaining your chainsaw almost enjoyable.
Whether you’re a weekend warrior or a professional, you’ll appreciate how much time and effort this tool saves you.
OSROENE Chainsaw Wrench 3-Pack, 13x19mm, Orange
- ✓ Bright, visible color
- ✓ Built-in hook for storage
- ✓ Durable steel construction
- ✕ Limited to specific sizes
- ✕ Might feel heavy for extended use
| Material | Heavy duty stamped steel with welded spindle |
| Wrench Sizes | 13mm and 19mm |
| Compatibility | Fits Stihl, Husqvarna, and other brands |
| Color | Bright orange spray paint coating |
| Design Features | Hook with mountaineering buckle for easy carrying |
| Intended Use | Tightening screws, removing/replacing spark plugs, adjusting chain tension |
The first thing that catches your eye when you pick up these OSROENE Chainsaw Wrenches is the vibrant orange color. It’s not just for show—this bright hue makes it impossible to lose your wrench in a cluttered toolbox or amidst outdoor debris.
Holding one, you’ll notice the sturdy T-shape design, which feels solid and balanced in your hand. The layer of orange spray paint gives it a rugged look, but it’s the hook welded on top that really stands out.
It’s like having a built-in tool holder—no more digging around for your wrench when you’re in a rush.
Using these wrenches is straightforward. You’ll find that the 13mm and 19mm sizes fit most chainsaws, especially Stihl and Husqvarna brands.
They slip onto screws and spark plugs with ease, allowing quick adjustments without hassle.
The heavy-duty stamped steel construction feels tough enough to handle frequent use. The welded spindle adds to its durability, so you won’t worry about it bending or deforming over time.
Storing them is a breeze, thanks to their compact size and rainproof coating. Whether you’re working in the rain or just organizing your garage, these wrenches stay protected and ready to go.
Overall, these tools make chainsaw maintenance faster and simpler. They’re a practical addition for anyone who wants to avoid wasting time hunting for the right wrench or dealing with flimsy tools.
RatchetScrench Chainsaw Tool 13/19 mm T-Bar Wrench
- ✓ Universal fit design
- ✓ Durable chrome vanadium steel
- ✓ Easy to use in tight spots
- ✕ Slightly bulky handle
- ✕ Limited to chainsaw maintenance
| Socket Sizes | 13 mm and 19 mm dual sockets for versatile chainsaw bar nut fitting |
| Material | Cold-forged chrome vanadium steel with manganese coating for corrosion resistance and durability |
| Tip Design | Dual-taper groove-cleaning tip for debris removal from bar-chain groove |
| Handle Length | 7-inch ergonomic ratcheting T-bar handle for increased torque and accessibility |
| Intended Use | Designed for professional and frequent chainsaw maintenance with field-tested durability |
| Compatibility | Universal fit design suitable for multiple chainsaw models |
Unboxing the RatchetScrench Chainsaw Tool feels like holding a precision instrument crafted for tough jobs. The 7-inch handle has a solid, cold-forged chrome vanadium steel build that immediately screams durability.
Its weight is just right—not too heavy, but substantial enough to feel reliable in your hand.
The dual 13 mm and 19 mm sockets are sleek, with a smooth finish that slides easily onto chainsaw nuts. What really catches your eye is the dual-taper groove-cleaning tip.
You can practically see the debris clearing away as you work, which makes maintenance feel less like a chore and more like a quick, satisfying task.
Using the T-bar handle is a game-changer. The ratcheting mechanism offers smooth, effortless adjustment, especially in tight spots or under full-wrap bars.
It’s clear this tool was designed by folks who know chainsaws inside out, because it handles heavy-duty tasks without any wobble or slipping.
The ergonomic design provides extra torque when you need it, making bar nut tightening or loosening faster and less tiring. Plus, the corrosion-resistant chrome vanadium sockets mean this tool is built to last, even if you work in muddy or damp conditions.
It feels like a dependable partner for daily saw maintenance, not just a quick fix.
Overall, this tool has a quality feel that’s hard to beat for the price. It’s perfect for any DIYer or professional who wants one tool that covers most chainsaw maintenance needs with ease and durability.
What Are the Key Features to Consider When Choosing the Best Chainsaw Tool?
When choosing the best chainsaw tool, several key features should be considered to ensure optimal performance and safety.
- Power Source: The chainsaw can be powered by gas, electricity, or battery. Gas-powered chainsaws are typically more powerful and suitable for heavy-duty tasks, while electric and battery-operated models are quieter, easier to maintain, and more environmentally friendly, making them ideal for light to medium jobs.
- Bar Length: The length of the bar affects the cutting capacity of the chainsaw. A longer bar allows for cutting thicker trees, but it can also make the tool heavier and more challenging to maneuver, so it’s important to choose a length that matches your intended use.
- Weight: The weight of the chainsaw influences its ease of use and portability. Lighter chainsaws are easier to handle for extended periods, making them suitable for homeowners or those with less physical strength, while heavier models might be more powerful but can cause fatigue over time.
- Safety Features: Look for chainsaws equipped with safety features such as chain brakes, low kickback bars, and hand guards. These features help to minimize the risk of accidents and injuries while operating the chainsaw, which is crucial for both novice and experienced users.
- Ease of Maintenance: A chainsaw that is easy to maintain will save you time and effort. Features like tool-less chain tensioning and automatic oilers can make it simpler to keep the chainsaw in good working condition, enhancing its longevity and performance.
- Ergonomics: Comfort during use is essential, so consider chainsaws with ergonomic handles and balanced designs. Features such as rubberized grips and adjustable handle positions can reduce strain on the user’s hands and arms, making it more comfortable to operate for longer periods.
- Noise Level: Chainsaws can be quite noisy, especially gas-powered models. If you are working in a residential area or want to minimize disturbance, look for quieter electric or battery-powered options that produce less noise during operation.
- Brand Reputation and Reviews: Researching brands and reading reviews can provide insight into the reliability and performance of specific chainsaw models. Choosing a reputable brand with positive user feedback can help ensure you invest in a quality tool that meets your needs.
What Types of Chainsaw Tools Are Available?
The best chainsaw tools include a variety of equipment designed for maintenance, safety, and efficiency in using a chainsaw.
- Chainsaw Sharpener: A chainsaw sharpener is essential for keeping the cutting chain in optimal condition, enhancing cutting performance and safety. It comes in various forms, including manual files, electric sharpeners, and guide systems, allowing users to choose based on convenience and frequency of use.
- Chainsaw Wrench: A chainsaw wrench is a versatile tool used for adjusting and tightening various components of the chainsaw, such as the bar nuts and chain tension. This tool typically features multiple sizes to fit different chainsaw models, ensuring that users can efficiently perform maintenance tasks.
- Bar and Chain Oil: Bar and chain oil is crucial for lubricating the chainsaw’s bar and chain, reducing friction and preventing wear. Using the right type of oil helps to extend the life of the chainsaw and ensures smoother operation, especially during prolonged use.
- Chainsaw Case: A chainsaw case provides protection and storage for the chainsaw when not in use. It helps to prevent damage to the chainsaw and its components, while also ensuring safe transport and reducing the risk of accidents.
- Safety Gear: Essential safety gear includes helmets, gloves, chaps, and eye protection, which are vital for preventing injuries while operating a chainsaw. Wearing the appropriate safety gear minimizes risks associated with chainsaw use, such as cuts, falls, and flying debris.
- Chain Tensioning Tool: A chain tensioning tool allows for quick and precise adjustment of the chain tension, which is critical for optimal performance. Proper tensioning ensures that the chain does not derail or cause excessive wear, contributing to the overall safety and efficiency of the chainsaw.
- Fuel Mix Can: A fuel mix can is specifically designed for storing pre-mixed fuel and oil for two-stroke engines, which are common in many chainsaws. Using a dedicated fuel mix can helps prevent contamination and ensures that the fuel is correctly mixed for maximum engine performance.
What Are the Advantages of Gas-Powered Chainsaw Tools?
The advantages of gas-powered chainsaw tools include several key features that make them suitable for various cutting tasks.
- Power and Performance: Gas-powered chainsaws typically offer more horsepower than their electric counterparts, allowing them to cut through thicker and denser materials with ease. This power makes them ideal for heavy-duty tasks such as felling large trees or cutting firewood.
- Portability: These chainsaws do not require an electrical outlet, allowing users to operate them in remote locations without worrying about extension cords or battery life. This makes them especially useful for professionals and homeowners who need to work in areas far from power sources.
- Durability: Gas-powered chainsaws are built to withstand tough conditions and heavy use, often featuring robust construction that can endure harsh environments. Their ability to handle rigorous workloads makes them a popular choice among logging professionals.
- Longer Run Time: Unlike electric chainsaws that may require frequent recharging, gas-powered models can run for extended periods, provided there is enough fuel. This is particularly advantageous for larger projects where continuous operation is necessary.
- Variety of Sizes and Models: Gas chainsaws come in a wide range of sizes and models, catering to different needs, from small residential tasks to large commercial operations. This flexibility allows users to choose a chainsaw that best fits their specific requirements and skill levels.
What Are the Benefits of Electric Chainsaw Tools?
The benefits of electric chainsaw tools include efficiency, ease of use, and environmental considerations.
- Quiet Operation: Electric chainsaws operate much more quietly than their gas counterparts, making them suitable for residential areas where noise restrictions may apply.
- Low Maintenance: These tools require significantly less maintenance than gas chainsaws; there is no need for fuel mixing, and they don’t have air filters or spark plugs to replace.
- Lightweight and Portable: Many electric chainsaws are lighter than gas models, making them easier to handle and maneuver, especially for prolonged use or for those who may have difficulty handling heavier equipment.
- Instant Start: Electric chainsaws can be started immediately with the push of a button, eliminating the hassle of pull-starting a gas engine, which can be particularly beneficial for beginners.
- Environmentally Friendly: Electric chainsaws produce no emissions during operation, contributing to a cleaner environment and reducing the carbon footprint associated with yard work and tree maintenance.
- Consistent Power: Electric models provide consistent power without the fluctuations that can occur with gas chainsaws, allowing for smoother cutting and more precise control.
Quiet Operation allows for use in noise-sensitive areas, making it an excellent choice for homeowners who need to trim or cut trees without disturbing the neighborhood. The Low Maintenance aspect is particularly appealing to users who want to spend more time cutting and less time on upkeep, as electric chainsaws do not require regular servicing like gas models.
The Lightweight and Portable feature makes electric chainsaws accessible for users of all skill levels, especially those who may struggle with heavier equipment. Instant Start is an invaluable feature for beginners or casual users who may find starting a gas chainsaw challenging; this ease of use encourages more people to engage in outdoor maintenance tasks.
Environmentally Friendly practices are becoming increasingly important to consumers, and electric chainsaws fit this need perfectly by eliminating harmful emissions. Finally, the Consistent Power provided by electric chainsaws ensures reliability during operation, allowing for efficient cutting with minimal interruptions, which is especially beneficial for larger jobs.
How Do Battery-Powered Chainsaw Tools Compare?
| Feature | Chainsaw A | Chainsaw B | Chainsaw C |
|---|---|---|---|
| Price | $150 – Affordable option with good features | $200 – Mid-range with additional functionalities | $250 – Premium model with advanced technology |
| Battery Life | 60 minutes – Suitable for small to medium tasks | 90 minutes – Good for extended use without recharging | 120 minutes – Excellent for larger projects |
| Weight | 8 lbs – Light and easy to handle | 10 lbs – Balanced, but heavier for prolonged use | 12 lbs – Heavier, best for experienced users |
| Cutting Power | 15 amps – Good for light cutting | 18 amps – More power for tougher jobs | 20 amps – High performance for heavy-duty tasks |
| Warranty | 2 years – Limited warranty covering defects | 3 years – Includes coverage for battery issues | 5 years – Comprehensive warranty for all parts |
| Chain Speed | 10 ft/s – Adequate for basic cutting | 12 ft/s – Faster for efficient work | 14 ft/s – High speed for quick cuts |
| Safety Features | Chain brake – Prevents accidental injuries | Low kickback chain – Enhances safety during use | Automatic oiler – Keeps chain lubricated and safe |
How Can You Safely Use a Chainsaw Tool?
To safely use a chainsaw tool, it’s essential to follow specific guidelines and practices that ensure both personal safety and optimal tool performance.
- Wear Personal Protective Equipment (PPE): Always wear appropriate PPE, including a helmet, eye protection, hearing protection, gloves, and chaps. This gear helps protect you from flying debris, noise, and potential cuts.
- Inspect the Chainsaw Before Use: Before starting, inspect the chainsaw for any damage or wear, including the chain tension, bar oil level, and safety features. Ensuring that the chainsaw is in good working order decreases the risk of accidents during operation.
- Understand the Operating Instructions: Familiarize yourself with the manufacturer’s operating manual for your specific chainsaw model. Knowing the controls, features, and recommended operating procedures can significantly reduce the likelihood of misuse.
- Maintain a Safe Work Environment: Clear the area of any obstacles, debris, or bystanders before starting your chainsaw. A clean workspace allows for better maneuverability and reduces the risk of accidents.
- Use Proper Cutting Techniques: Employ appropriate cutting techniques, such as using the correct stance, keeping both hands on the saw, and avoiding kickback. Proper technique enhances control and minimizes the chance of the chainsaw unexpectedly reacting.
- Keep the Chainsaw Well-Maintained: Regular maintenance, including sharpening the chain and checking the tension, is crucial for efficient operation. A well-maintained chainsaw performs better and is safer to use than one that is neglected.
- Be Aware of Your Surroundings: Always be mindful of your surroundings, including overhead power lines and the potential for falling branches. Awareness can prevent accidents and injuries while operating your chainsaw.
Which Brands Are Recognized as the Best for Chainsaw Tools?
The main brands recognized for producing the best chainsaw tools include:
- Stihl: Stihl is renowned for its durable and high-performance chainsaws, making it a favorite among both professionals and hobbyists. Their extensive range includes gas, electric, and battery-operated models, each designed with innovative technology for optimal efficiency and safety.
- Husqvarna: Husqvarna is another leading brand known for its powerful and reliable chainsaws suitable for a variety of tasks. They offer models that cater to both casual users and heavy-duty professionals, featuring advanced features like low-vibration technology and ergonomic designs for improved handling.
- Echo: Echo chainsaws are praised for their robust build quality and excellent cutting performance. They provide a range of lightweight and easy-to-handle options, making them ideal for homeowners and those new to chainsaw use, while still offering models for more demanding applications.
- Makita: Makita is well-respected for producing electric and battery-powered chainsaws that deliver consistent power and performance. Their tools are particularly favored by urban users and those seeking quieter operation without compromising on cutting efficiency.
- DeWalt: DeWalt is known for its reliable battery-operated chainsaws that combine portability with solid performance. Their products are designed for convenience, featuring brushless motors for longer runtime and less maintenance, making them a popular choice for DIY enthusiasts.
What Are the Most Common Uses for Chainsaw Tools?
The most common uses for chainsaw tools include:
- Tree Felling: Chainsaws are primarily used for cutting down trees, especially larger ones. They provide the necessary power and efficiency to make clean cuts through thick trunks, making the process quicker than using manual saws.
- Limbing: After a tree has been felled, chainsaws are used for limbing, which involves removing the branches from the trunk. This makes it easier to transport the wood and helps in clearing the area, ensuring safety and efficiency.
- Buckling: Chainsaws are also used to cut logs into smaller, manageable pieces, known as bucking. This is particularly useful for preparing firewood or managing timber for further processing.
- Carving: Some chainsaws are designed for artistic purposes, allowing users to create intricate wood carvings. Specialized chainsaw carving tools enable artists to produce detailed sculptures from wood, showcasing the versatility of chainsaws beyond traditional uses.
- Trimming and Pruning: Chainsaws can be used for trimming trees and shrubs, especially when dealing with overgrown vegetation. They provide an efficient means to maintain the shape and health of trees and hedges, making landscaping tasks easier.
- Firewood Preparation: Chainsaws are essential for cutting logs into appropriate sizes for firewood. By quickly and easily reducing larger pieces of wood, they help homeowners stock up on fuel for heating during colder months.
- Storm Cleanup: After severe weather events, chainsaws are invaluable for clearing fallen trees and debris. They allow for rapid response to restore access and safety in affected areas, making them a crucial tool for emergency services and homeowners alike.
How Should You Maintain Your Chainsaw Tool for Optimal Performance?
To maintain your chainsaw tool for optimal performance, consider the following essential practices:
- Regular Cleaning: Keeping your chainsaw clean is crucial for its longevity. After each use, remove any debris, sawdust, and oil buildup from the chain, bar, and air filter to prevent clogging and ensure smooth operation.
- Chain Lubrication: Proper lubrication of the chain is necessary to reduce friction and wear. Always check the oil level in the reservoir and apply bar and chain oil regularly, especially during extended use, to keep the chain running smoothly.
- Chain Tension Adjustment: Maintaining the correct tension on your chainsaw chain is vital for safety and performance. A properly tensioned chain should be snug against the bar without being overly tight; check and adjust the tension before each use to prevent damage.
- Sharpening the Chain: A sharp chain is essential for efficient cutting and reduces the risk of kickback. Regularly check the sharpness of the chain and use a file or sharpening tool to maintain the cutting edges, ensuring that the chainsaw operates at peak efficiency.
- Inspecting the Bar and Chain: Regular inspection of the guide bar and chain for wear or damage is important for safe operation. Look for signs of bending, cracks, or excessive wear; replace any damaged parts to avoid accidents and maintain cutting performance.
- Checking the Fuel System: A well-maintained fuel system is key to the reliable operation of your chainsaw. Regularly inspect the fuel filter, ensure the gas and oil mixture is correct, and replace stale fuel to prevent starting issues and poor performance.
- Storing Properly: Proper storage of your chainsaw can prevent damage and prolong its life. Store in a cool, dry place, and consider using a protective cover; also, drain the fuel if storing for an extended period to avoid fuel degradation.