Amsoil 4 in 1 Diesel Fuel Additive

All in one is now 4 in 1. Cetane, lubricant, cold flow and the cleaner. Best Diesel Fuel additive you can buy.

AMSOIL Diesel 4 in 1 (ADB) combines superior detergency and improved lubricity of Diesel Injector Clean, the excellent cold-flow and anti-gelling of AMSOIL Diesel Cold Flow and the increased horsepower and cetane of AMSOIL Cetane Boost. See what I mean!

SKU: ADB Category:

Diesel All-In-One now called 4 in 1 fuel treatment

All-season protection and performance

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.

Buy & Check Price& Bottle Sizes

Restores Horsepower & Improves Fuel Economy enough to notice!

All in one is now 4 in 1. Cetane, lubricant, cold flow and the cleaner. Best Diesel Fuel additive you can buy. Fuel injector deposits interrupt spray patterns, causing poor fuel atomization, incomplete combustion, excessive emissions and smoke. High-pressure common-rail fuel systems are becoming commonplace as vehicle manufacturers attempt to produce more power while still meeting tightening emissions standards. In high-pressure common-rail systems, injection pressures can be 30,000 psi and higher to atomize the fuel into a fine mist for more efficient combustion, yielding increased power and fuel economy while reducing emissions. To maintain these high pressures, injector assemblies are highly engineered, with clearances as tight as 1-3 microns (a human hair is typically 70-100 microns thick). Even minimal internal diesel injector deposits on the injector pintal or other components can lead to sticking and even seizure, reducing power, fuel economy and operability. Traditional additive chemistry is not designed to address these tough-to-remove deposits.

Diesel Four in One features advanced chemistry that delivers concentrated strength to target internal diesel injector deposits and traditional carbonaceous deposits, helping to restore horsepower and operability to like-new condition. Acceleration is improved and, with regular use, Diesel 4 in1  continues to enhance performance by keeping injectors clean. The net savings on fuel can result in no additional cost of ownership.

Product Data Bulletin

 

Download PDFProduct Datasheet

Lubricates Fuel Pump & Injectors to Reduce Wear

Ultra-low-sulfur diesel fuel (ULSD) provides significantly reduced lubricity – a critical property in controlling wear in fuel pumps and injectors. Diesel All-In-One (now 4 in 1) adds back the lubricity the fuel pump and injectors need, reducing wear, improving service life and saving time and money on maintenance costs.

Improves Fuel Quality for Peak Performance

Fuel with a higher cetane number provides for a more complete burn, resulting in improved performance. By increasing cetane, 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

As the temperature drops, the wax naturally found in diesel fuel begins to crystallize. The point at which wax crystals form is known as the cloud point. These wax crystals eventually clog the fuel filter and starve the engine of fuel, preventing it from starting. While low-quality fuels may form wax crystals in temperatures as warm as 40ºF (4ºC), most fuels have a cloud point near 32ºF (0ºC). The point at which the crystals clog the fuel filter is known as the cold filter-plugging point (CFPP). Diesel 4 in 1 lowers the CFPP by up to 40ºF (22ºC) in ULSD.

  • 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 40ºF
  • Delivers maximum horsepower
  • Increases cetane up to 4 points
  • Safe for use in all diesel fuels, including biodiesel
  • Alcohol-free
  • Extra money for a nice meal

Extends Filter Life

Modern diesel engines run hot, raising the temperature of the fuel returned to the tank and causing carbonaceous deposits that collect in the fuel filter (see picture), plugging it and causing premature failure issues. AMSOIL Diesel 4 ion 1 effectively protects against deposits, extending fuel filter life.

RECOMMENDATIONS

Diesel 4 ion 1 is recommended for use with all types of heavy- and light-duty, on- or off-road and marine diesel engines. Use maintenance dose for regular treatment. Add before filling tank. Diesel 4 ion 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.

AMSOIL PRODUCT WARRANTY
AMSOIL products are backed by a Limited Liability Warranty. For complete information visit AMSOIL Warranty Information.

High-Pressure Common-Rail Fuel Injector Pintal                                                      Traditional Fuel Injector Pintal

High-Pressure Common-Rail Fuel Injector Pintal

.

Fuel injectors in high-pressure common-rail diesel engines use smaller, highly engineered components to produce the higher fuel pressures needed for improved combustion. The tighter clearances invite internal diesel injector deposits that interfere with injector needle actuation, reducing performance. External deposits can also form on the injector nozzle (the typical trouble spot for traditional injectors). While many other fuel additives have yet to catch up to the internal diesel injector deposit problem, AMSOIL Diesel 4 ion 1 targets deposits wherever they form, maximizing power, fuel economy and performance in high-pressure common-rail and traditional diesel engines.

 

Customer Comments and Remarks on the Diesel All In One

 

Great products
By  MICHAEL,  a  Verified Buyer  from  Iowa  on  January 29, 2025
I have been using AMSOIL diesel products for a while and they are great. Doing testing for winter weather was fun. I compared several different “cold weather additives”. Here in Iowa it does get around -10F and at times -20F with wind chill on average. This year it got to -36F. To my surprise, there were other friends and neighbors that gelled up, including agricultural equipment. (NOT ME) So, for free I used AMSOIL RECOVERY, combined with COLD FLOW. Removed all filters, removed/cleaned/reinstalled fuel water separators if equipped, filled those with recovery and dumped rest in diesel tank. Once started put COLD FLOW and ALL-in-ONE in the tank. The reason for this, the tanks are huge. I needed more COLD FLOW than lubing, but I wanted to also lube the complete diesel fuel system. Once I convinced people that these products are the real deal, this is what they use now. From using oil, filters, diesel products, transmission products. THANK YOU AMSOIL