LX4 Lubricity Extreme

Resolves CP4 High-Pressure Fuel Injection Pump incompatability issues with American produced Ultra-Low Sulfur Diesel (ULSD) fuel


The Problem with The CP4 Fuel Pump

Many diesel owners are on high alert. With a recent lawsuit claiming that the Bosch CP4 high-pressure fuel injection pump installed within a variety of diesel vehicles is failing prematurely, many are questioning the use of the CP4, how to repair failing pumps, and what preventative measures there are to avoid becoming another statistic of costly repairs.

A variety of vehicles makes and models are susceptible to the failing CP4 pump:

  • 2011-2016 Chevrolet Silverado 2500HD / 6.6L V8 Duramax LML engines
  • 2011-2016 Chevrolet Silverado 3500HD / 6.6L V8 Duramax LML engines
  • 2011-2016 GMC Sierra 2500HD / 6.6L V8 Duramax LML engines
  • 2011-2016 GMC Sierra 3500HD / 6.6L V8 Duramax LML engines
  • 2011-2016 3500HD / 6.6L V8 Duramax LML engines
  • 2010-2011 Chevrolet Express
  • 2010-2011 GMC Savana
  • 2010-2011 GMC Sierra box-delete
  • Certain 2011-2012 Chevrolet Silverado HD / 6.6L Duramax LGH.
  • Certain 2011-2012 GMC Sierra HD / 6.6L Duramax LGH
  • 2011-present Ford pickups / 6.7L V8 Powerstroke diesel engines
  • 2014-present Dodge Ram pickups / 3.0L diesel
  • 2014-present Jeep Grand Cherokees / 3.0L diesel
  • 2011-2015 Audi A6 / 3.0L TDI
  • 2013 Audi A7 / 3.0L TDI
  • 2013-2016 Audi A8 / 3.0L TDI
  • 2013-2017 Audi Q5 / 3.0L TDI
  • 2012-2015 Audi Q7 / 3.0L TDI
  • 2012, 2014 VW Touareg / 3.0L TDI
  • 2011 Porsche Cayenne/ 3.0 S 4


Increases fuel lubricity up to 56% Protects CP4 fuel pumps and fuel injectors from premature wear and failure Increases fuel lubricity by more than double that of the closest competitor Reduces pintle scoring & wear Extends the life of the CP4 fuel pump and fuel system Helps lubricate the upper cyclinder

The Cause of the CP4 Fuel Pump Problem

The Cause of the CP4 Failures: Lack of Lubricity in the Fuel

Ultra-Low Sulfur Diesel (#2 Diesel) = Ultra-Low Lubricity Diesel.

Today’s Ultra-Low Sulfur Diesel (ULSD) does not contain the lubricity needed to fully protect our vehicles. The Bosch CP4 fuel pump has an unusually high failure rate in the U.S., upwards of 7%, when compared to 1% failure rate in Europe. So why is the failing CP4 being installed in so many vehicles? When leaving the manufacturer the CP4 pump is typically successful because the pump is manufactured in Europe. The difference between the USA and Europe is that the lubricity properties have not been removed from the European diesel fuel, as it has in the U.S. fuel. The European EN-590 diesel fuel has a wear scar diameter 460-micron specification while in the U.S. the base is 520-micron in ASTM US D-975. Therefore, the failure is caused by the lack of lubricity in ultra-low sulfur fuel in the USA.

More so, the failure is the lack of the proper additives used to supplement fuel degradation and the ability to restore the lubricity that is easily available. For those that have gone without these fuel lubricity components and simply relied on the untreated fuel, yes, the lack of lubricity in ULSD fuel has caused the breakdown. With one extra step, however, by adding the correct fuel additive, lubricity can be restored, and the pump will operate in a similar circumstance as originally manufactured in Europe.

The lack of lubricity in ULSD is the main factor in the catastrophic failures of the CP4 Fuel pumps. High rates of wear from lack of lubricity can introduce metal shavings into the fuel system. These metal shavings create wear that damages your injectors, cylinder walls, pistons, and rings costing several thousands of dollars to repair.

The CP4 Failure Defined:

In an attempt to improve fuel efficiency, the CP4 injection pump replaced the CP3 pump to create a higher-pressure expulsion with less fuel volume consumed.

With the lack of ability to supply the adequate fuel needed, thereby also reducing the amount of lubrication to the system, the CP4 forms air bubbles inside the injectors. When air is within the system, there is no fuel. Where there is no fuel there is no lubrication. Where there is no lubrication, there is instead metal on metal friction, causing accelerated wear and components to fail.

During the degradation of the parts, metal shavings are traveling through the entire fuel system, including the fuel injectors and the fuel lines thereby causing more friction and abrasive compounds throughout the travel of the fuel.

The attempt to reduce fuel consumption is a compounded effect of low-quality fuel with less sulfur lubricity, and then less of the fuel itself. The double negative is a direct reduction of lubricity in the system.

The Solution to CP4 Pump Failure

Use Hot Shot’s Secret LX4 Lubricity Extreme


LX4 Lubricity Extreme is a premium lubricity additive for Ultra-Low Sulfur Diesel (ULSD) and gasoline. Hot Shot’s ultra-low sulfur diesel additive contains the highest level of lubricity performance on the market and can put even the poorest quality fuel back into the specification of, and exceed, OEM requirements for lubrication. Use this CP4 fuel system saver to greatly increase fuel’s lubricity and prevent the wear and scarring of key components inside the fuel system, including pumps and injectors. This diesel fuel lubricant is warranty safe and emissions equipment safe.

The Engine Manufacturers Association recommends all diesel fuel should be below the 460-micron specification to protect all fuel injection systems. 3rd party ASTM D-6079 testing of LX4 showed that fuel that was out of specification would be brought down below the 460-micron level that is necessary to protect injectors and pumps from premature failure.
LX4 case study

By increasing the lubricity of the diesel fuel the Wear Scar Diameter is lowered. By bringing the Wear Scar Diameter back below the recommended threshold, excessive wear is prevented. Give your fuel system the protection it needs, add LX4 CP4 fuel system saver to every fill up to save you the time, headache and expense of replacing the fuel system before failure occurs.

100% compatible with other Hot Shot’s Secret fuel additives, including DIESEL EXTREME, EVERYDAY DIESEL TREATMENT and GASOLINE EXTREME. Follow recommended treat rates.

  • 32oz – Treats up to 360 gallons

  • 4oz – Treats up to 40 gallons

  • 16 oz – Treats up to 160 gallons



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If any of our products do not deliver as promised, then we will give your money back.

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We understand what it’s like to be disappointed by products that do not live up to their claims. That’s why all Hot Shot’s Secret products are subject to rigorous, scientific, triple-threat testing:

Testing in our world-class R&D lab
Independent, third-party dynamometer testing
Real-world testing
We know what the results are before you buy the product, ensuring that the product you purchase outperforms the other solutions on the market.