AMSOIL Diesel 4-IN-1
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All-Season Protection and Performance
AMSOIL Diesel 4-IN-1 combines the superior detergency and improved lubricity of AMSOIL Diesel Injector Clean, the excellent cold-flow and anti-gelling properties of AMSOIL Diesel Cold Flow and the increased horsepower and cetane of AMSOIL Cetane Boost in one convenient package, providing the full potency and benefits of all three products.
It is safe for use in all diesel fuels, including biodiesel. Diesel 4-IN-1 is specially engineered to provide exceptional all-season protection for a serious performance boost. One dose delivers outstanding detergency, improved lubricity, better cold flow and higher cetane.
Key Benefits
- Cleans dirty injectors
- Lubricates pumps and injectors to reduce wear
- Extends fuel-filter life
- Improves fuel economy up to 8%
- Combats fuel-system corrosion
- Prevents wax settling during storage
- Lowers cold filter-plugging point (CFPP) by up to 40°F (22°C)
- Delivers maximum horsepower
- Increases cetane up to 4 points
- Safe for use in all diesel fuels, including biodiesel
- Alcohol-free
Proven Performance
Restores Horsepower & Improves Fuel Economy. Fuel injector deposits interrupt spray patterns, causing poor fuel atomization, incomplete combustion, excessive emissions and smoke. In high-pressure common-rail systems, injection pressures can be 30,000 psi and higher, and injector clearances are as tight as 1-3 microns (a human hair is typically 70-100 microns thick). Even minimal internal diesel injector deposits can lead to sticking and seizure. Diesel 4-IN-1 features advanced chemistry that targets internal diesel injector deposits and traditional carbonaceous deposits, helping restore horsepower and operability to like-new condition.
Lubricates Pumps & Injectors. Ultra-low-sulfur diesel fuel (ULSD) provides significantly reduced lubricity. Diesel 4-IN-1 adds the lubricity the fuel pump and injectors need, reducing wear and improving service life.
Improves Fuel Quality. By increasing cetane up to 4 points (maintenance dose), Diesel 4-IN-1 improves the ignition quality of diesel fuel, maximizing available power and improving starting. It also smooths idle and reduces smoke and emissions.
Helps Prevent Gelling. Diesel 4-IN-1 lowers the cold filter-plugging point (CFPP) by up to 40°F (22°C) in ULSD.
Extends Filter Life. Diesel 4-IN-1 effectively protects against carbonaceous deposits that collect in the fuel filter, extending fuel filter life.
Applications
Use AMSOIL Diesel 4-IN-1 in all types of heavy- and light-duty, on- or off-road and marine diesel engines. Add before filling tank. Diesel 4-IN-1 must be added at temperatures above the diesel fuel cloud point (the temperature at which wax begins to crystallize). It will not reverse gel or wax crystals once formed.
Maintenance dose (up to 4-point cetane increase):
- 2 oz (59.1 mL) treats 5 gal (18.9 L)
- 4 oz (118.3 mL) treats 10 gal (37.9 L)
- 8 oz (236.6 mL) treats 20 gal (75.7 L)
- 12 oz (354.9 mL) treats 30 gal (113.6 L)
- 16 oz (473.2 mL) treats 40 gal (151.4 L)
- 64 oz (1.9 L) treats 160 gal (605.7 L)
Pros and Cons
Pros
- Cleans dirty injectors
- Lubricates pumps and injectors to reduce wear
- Extends fuel-filter life
- Improves fuel economy up to 8%
- Combats fuel-system corrosion
- Prevents wax settling during storage
- Lowers cold filter-plugging point (CFPP) by up to 40°F (22°C)
- Delivers maximum horsepower
- Increases cetane up to 4 points
- Safe for use in all diesel fuels, including biodiesel
- Alcohol-free
Cons
- Premium Investment: Higher initial cost compared to conventional or "shelf-brand" synthetic oils.
- Limited Local Retail: Primarily available through authorized dealers and specialized synthetic outlets. National Synthetics is a local stocking dealer. Call 1-678-944-8816 to confirm in-stock items for same-day local pickup.
Order Through Your Independent AMSOIL Dealer
Order AMSOIL Diesel 4-IN-1 through your independent AMSOIL Dealer. Preferred Customer members save up to 25% on all AMSOIL products.
Independent AMSOIL Dealer #1858536
Shipping & Returns
Fast, Reliable Shipping
- Free standard ground shipping on orders of $100 ($130 in Canada) or more.
- Orders under the threshold ship for a flat $9.99 ($12.99 in Canada) freight charge.
- In-stock items typically delivered in two to three business days.
- U.S. and Canada only — no shipments to PO Boxes.
30-Day Return Policy
- Return unopened, currently marketed products within 30 days for a full refund (minus freight).
- Exchange unopened products within 90 days with no restocking fee.
- Special-order items are non-returnable.
- Returns are handled directly by AMSOIL.
Frequently Asked Questions
AMSOIL Diesel 4-IN-1 combines the detergency and lubricity of AMSOIL Diesel Injector Clean, the cold-flow and anti-gelling protection of AMSOIL Diesel Cold Flow, and the horsepower and cetane boost of AMSOIL Cetane Boost in one convenient package. One dose delivers outstanding detergency, improved lubricity, better cold flow and higher cetane.
Diesel 4-IN-1 lowers the cold filter-plugging point (CFPP) by up to 40°F (22°C) in ultra-low-sulfur diesel (ULSD).
Use AMSOIL Diesel 4-IN-1 in all types of heavy- and light-duty, on- or off-road and marine diesel engines. It is safe for use in all diesel fuels, including biodiesel.
Add before filling the tank. Diesel 4-IN-1 must be added at temperatures above the diesel fuel cloud point (the temperature at which wax begins to crystallize). It will not reverse gel or wax crystals once formed. For emergency treatment of already-gelled fuel, use AMSOIL Diesel Recovery.
Independent AMSOIL Dealer #1858536. Product information sourced from AMSOIL. Visit AMSOIL.com for the most current product details and availability.