8/9/2019 CJ-4 Fuel Dilution Pickups

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TSB: MO-2009-10-01

Date: 10/29/09

Product Description: AMSOIL Premium API CJ-4 Diesel Oils (DEO, DME)

Subject: Fuel dilution issues in 2007 2010 light-duty turbo-diesel pickups.

Technical Service Bulletin

OBJECTIVE:Communicate the discovery and cause of excessive fueldilution in 20072010 light-duty diesel pickups from Ford,GM and Dodge and the resultant reduction in the draininterval recommendation for AMSOIL Premium Diesel Oilsin these applications.

ISSUES:AMSOIL has documented increasing levels of diesel fuelcontamination (fuel dilution) in the engine oil in 20072008 light-duty diesel pickups from all major vehicle

manufacturers, and indications are that 2009 - 2010models are affected as well.

Research indicates that fuel dilution is intensifying due tothe use of in-cylinder post-fuel injection during the enginesexhaust stroke to regenerate the diesel particulate filter(DPF).

Fuel in the oil reduces the oils life expectancy andeffectiveness. Because diesel fuel is a natural solvent, fueldilution in motor oil causes a decrease in viscosity whichmay lead to an increase in engine wear rates.

TECHNICAL DISCUSSION:

Current emissions legislation set by the EnvironmentalProtection Agency (EPA) mandates that all 2007 andnewer on-highway diesel-fueled vehicles come equippedwith a DPF. A DPF is generally a honeycomb-like filterpositioned in the exhaust stream to collect particulatematter and soot to prevent it from exiting the vehicle. DPFsare highly efficient and can usually remove 80-90 percentof particulate matter from diesel exhaust.1 When the filteris near its capacity, soot trapped in the filter is burned,freeing the plugged media and enabling the filter to remainserviceable. The process of burning the residual matter istermed regeneration and can be either active or passive.

Active regeneration uses raw diesel fuel as a combustion

source to burn the accumulated soot and clear the filter.Active regeneration is accomplished using either in-streamor in-cylinder injection. In-stream injection systems injectraw diesel fuel directly into the exhaust stream before itreaches the DPF. In-cylinder injection systems inject rawdiesel fuel directly into the cylinder on the exhaust stroke.The unburned fuel evaporates and travels down to the

DPF to burn out the soot built up in the filter.

Passive regeneration requires exhaust gas temperaturesof approximately 600C (1100F).2 These relativelyhigh exhaust gas temperatures occur naturally intrucks operating under heavy load and can trigger thecombustion of soot in DPFs. Passive regeneration doesnot increase fuel consumption the way active regenerationdoes because, by design, it does not require the injectionof additional fuel to increase exhaust temperatures.

All class 8 over-the-road tractors and medium-classapplications use active regeneration via in-stream injection.In this method, diesel fuel used to burn soot in the DPF isinjected directly ahead of the DPF and does not reach thecrankcase, leaving the oil uncontaminated.

Light-duty diesel pickup manufacturers (Dodge, Ford, GM)have opted for a less-costly in-cylinder injection system.With in-cylinder injection systems, raw diesel fuel injectedon the exhaust stroke can wash directly past the rings andinto the crankcase, mixing with the oil. Regular washing ofcylinders is a continuous source of fuel contamination inthe crankcase and is not conducive to long-term engineprotection. Used oil analysis results from 20072010 light-

duty diesel vehicles showed some elevated fuel dilution,but at tolerable levels.

NOx reduction - EPA emission mandates taking effect in2010 require the reduction of nitrogen oxides (NOx) to .2grams per brake horsepower (g/bhp). To meet this limit,engine manufacturers will use either selective catalyticreduction (SCR), NOx adsorbers or advanced exhaust gasrecirculation (EGR).

Most over-the-road truck and tractor manufacturers willuse SCR technology, with International the only majormanufacturer to use high EGR technology. Neither systemis expected to increase fuel dilution. Light-duty diesel

pickup manufacturers Ford and GM also will use SCRtechnology in their 2011 model-year trucks. Dodge plans toemploy SCR technology in its medium-duty chassis cabsbut plans to continue use of its NOx adsorber technologyin the companys light-duty pickups.

Submitted By: MB Reviewed By: DP Approved By: AA Approval Date: 10/29/09

Distribution: Internal All X

AMSOIL INC., AMSOIL Bldg., Superior, WI 54880 (715) 392-7101 Copyright 2009

Risley Distribution: 441688 tomsnowmobile02@yahoo.comhttp://www.lubedealer.com/SyntheticlubeRiz/

8/9/2019 CJ-4 Fuel Dilution Pickups

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Submitted By: MB Reviewed By: DP Approved By: AA Approval Date: 10/29/09

Distribution: Internal All X

AMSOIL INC., AMSOIL Bldg., Superior, WI 54880 (715) 392-7101 Copyright 2009

Like DPFs, NOx adsorbers need to be regenerated. How-ever, they require significantly more fuel to regenerate thanDPFs do, which only compounds the fuel dilution problem.In Dodge light-duty turbo-diesel pickups, the combinedregeneration requirements of the DPF and NOx adsorbertechnologies are causing high fuel dilution of the engineoil.

As illustrated in the charts, model-year 2007 and newerlight-duty diesels are experiencing higher fuel dilutionthan previous model years. Although these vehicles areexperiencing higher fuel dilution, regeneration cyclesvary based on service (engines operating in severeservice conditions do not actively regenerate as often as

engines operating in normal service conditions), and someapplications are affected more than others. While not all20072010 light-duty diesel vehicles develop this problem,fuel contamination can reduce oil viscosity and decreasefilm thickness. Other concerns include significantly reducedfuel economy, accelerated engine oil oxidation, increasedvolatility and overfilling of the oil sump.

RECOMMENDATION:

Although AMSOIL Premium Diesel Oils have shown theability to maintain integrity under fuel-dilution conditions,the abnormally high rate and unkown long-termeffects have forced AMSOIL to adjust its drain intervalrecommendations as a precautionary measure for 20072010 Dodge 6.7L, Ford 6.4L and GM 6.6L LMM light-dutyturbo-diesel pickups.

In these applications, AMSOIL recommends changingAMSOIL Premium API CJ-4 Synthetic Diesel Oils (DEO,DME) at the manufacturer-recommended drain interval.Drain intervals may be extended further with oil analysis.The recommendation for these oils in gasoline applicationsremains 2X vehicle manufacturer recommendation.3

Owners of affected vehicles should use oil analysis todetermine the severity of fuel dilution in their vehicle. If fueldilution levels are above 5 percent, contact the dealershipor OEM for help finding a solution. AMSOIL and OILANALYZERS condemn oils with greater than 5 percentfuel dilution.

While AMSOIL does not have extensive documentationof fuel dilution trends for 20092010 models, it is safe toassume fuel dilution will remain an issue because thesemodels employ the same DPF regeneration technology as20072008 models.

Pre-2007 diesel applications not equipped with emissionsystem devices are not affected by these changes. Thoseapplications can still extend oil drain intervals to 3X vehiclemanufacturer recommendation, not to exceed 50,000miles/600 hours or one year.3

REFERENCES:1. Clean Air Fleets Emission Control Technology.

Accessed March 5, 2009.www.cleanairfleets.org/ect

2. Ranalli,Marco, et al. DPF Soot Mapping. A Simpleand Cost Effective Measurement Method for SeriesDevelopment. Accessed July 24, 2009.

http://www.arvinmeritor.com/media_room/CAS_Europe/sae_dpf_en.pdf.

3. Refer to the AMSOIL Product Recommendation andDrain Interval Chart (G1490) for details.

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