Mercury – Quicksilver 10W-40 Full Synthetic Off-Road Engine Oil | 4-Stroke Protection | Full Synthetic Formula | 8M0128395

Overview

If you spend your free time on trails, dirt roads, or tucked deep into the woods, you already know how unpredictable off-road riding can be. One minute you’re cruising across hardpack, the next you’re crawling through mud, rocks, or steep switchbacks. In those moments, you need an engine that responds instantly, stays cool under pressure, and never fights against the conditions. Quicksilver 10W-40 Full Synthetic Off-Road Engine Oil gives you that kind of confidence — the feeling that your ATV, UTV, or dirt bike is ready for whatever the day throws your way. It’s smooth, dependable, and built to protect engines that take more than their fair share of abuse.

Key Features

• Full synthetic 10W-40 formula engineered for off-road 4-stroke engines
• Designed to protect against fuel dilution, corrosion, and extreme temperature swings
• Additives help safeguard internal components from moisture and wear
• Exceeds major manufacturer and industry specifications
• Ideal for all 4-stroke ATVs, UTVs, and off-road motorcycles
• Provides strong startup protection in all seasons and climates
• Packaged in an easy-handling one-quart bottle

Engine & Boat Compatibility

(Per template — motorcycles and powersports only)

• Compatible with all major 4-stroke ATV and UTV brands
• Works in off-road motorcycles that experience high RPM, heat, and load changes
• Suitable for liquid-cooled and air-cooled engines
• Safe to use without affecting manufacturer warranties

Performance & Practical Benefits

Off-road engines rarely get an easy life. They’re pushed hard, revved high, and run through dust, mud, water crossings, and wide-open straights — often all in the same day. Quicksilver’s full synthetic blend is designed specifically for that kind of unpredictable punishment. It flows quickly at startup, even on cold mornings, giving your engine a smooth, steady feel right from the first turn of the key. As temperatures climb, the oil maintains its viscosity, keeping moving parts cushioned and protected instead of thinning out or breaking down.

You’ll notice the difference during long rides, too. The engine runs cleaner, cooler, and more responsive, even when the terrain demands sudden throttle changes or slow crawling over rough ground. The added corrosion protection is a big plus, especially for riders who store their machines between seasons or deal with wet environments. This Mercury Marine part number also helps reduce oxidation, meaning it stays cleaner longer and preserves performance across extended service intervals. No matter how hard you push your machine, the reliability holds steady — and that’s something every off-road rider can appreciate.

Why Buy OEM

When it comes to oils designed for extreme environments, Quicksilver has built its reputation on engineering lubricants that withstand harsh conditions far beyond what most engines encounter. Their marine-grade testing carries over directly into their off-road formulations. That means this oil isn’t just built to meet standards — it’s designed to exceed them, offering long-term reliability and better protection than many generic blends. Choosing an OEM-trusted product like this one helps avoid premature wear, improves performance, and saves money over time by keeping your engine running the way it should.

FAQ

Q1: Which engines does this oil fit?

It’s made for all 4-stroke off-road motorcycles, ATVs, and UTVs from major manufacturers.

Q2: What makes it better than aftermarket alternatives?

Its full synthetic blend offers superior protection against heat, corrosion, and fuel dilution — all common in off-road conditions.

Q3: How can I confirm it’s right for my setup?

Check your owner’s manual. If your engine calls for 10W-40 and a JASO-certified oil, this part number is an excellent match.

Q4: Can it be used in extreme climates?

Absolutely. It provides strong performance in both hot and cold environments and is designed for year-round use.

Q5: Is installation straightforward?

Yes. Changing oil is simple for most riders, and the quart bottle pours cleanly without mess.