L U B E M A G A Z I N E N o . 9 5 F E B R U A R Y 2 0 1 028

IntroductionThe Western European engine oil marketcontinues to undergo a period ofdramatic change as the result of threefactors: changing emissions legislation,increased fuel economy requirementsand the need to maintain durabilityunder severe operating conditions.Changes in these market drivers hasresulted in the development of newengine oil technology, designed tooperate in vehicles with the latestaftertreatment systems, while deliveringever greater durability and fuel economyimprovement. It is expected that theneed for engine oils to deliver evengreater levels of fuel economyimprovement may have the singlegreatest impact on the type of engine oilthat is used over the next five years.

Improving fuel economyThe need to increase the fuel efficiencyof vehicles is driven by a number offactors including:• reducing carbon dioxide (CO2)

emissions• lowering operating costs• reducing fossil fuel consumption

At the end of 2006 there were over 250million vehicles in use (on-road) in theEuropean Union (EU) and these wereresponsible for 26% of man-made CO2

emissions1. With legislators continuing tolook at taxation, fines and differentincentive schemes to achieve a reduction

in CO2 emissions it is expected thatOEMs will be required to further improvethe fuel efficiency of their vehicles. AsOEMs continue to make changes to bothvehicle and engine design to improve thefuel efficiency of their vehicles they willalso look to the engine oil to provide ameasure of fuel economy improvementtoo.

Passenger car engine oilsThe evaluation of fuel economy has beena requirement for some passenger carengine oils for many years. Tests toevaluate fuel economy improvement areembedded in the ACEA passenger carand light duty diesel engine oil sequencesand many passenger car OEM specifi-cations. This has led to the move tolighter viscosity grades, the use of “lowHTHS”2 passenger car engine oils and theintroduction of new friction modifiertechnologies. However, the EuropeanUnion (EU) proposes to begin phasing ina system of fines from 2012 for OEMsbased on the CO2 emissions of theirvehicles. This will lead to an increaseddemand for engine oils to deliver greaterfuel economy improvement than today.

Heavy duty diesel engine oilsThe drive to Increased fuel efficiency forheavy duty vehicles is driven primarily bya desire to lower operating costs. This isleading to a shift in the typical viscositygrades used from 15W-40 and higher to10W-40 and 5W-30. However, unlike for

passenger cars, there are no standardtests for the evaluation of heavy dutydiesel engine oil fuel economyimprovement. Therefore, it is essentialthat any claims of fuel economyimprovement are carefully evaluated toensure that they will be measurable inthe field. This will become even moreimportant over the next few years ascurrent legislation does not consider thereduction of carbon dioxide (CO2)emissions, although it is likely that thiswill become a future requirement.

The role of engine oilsEngine oils can contribute toimprovements in fuel economy in twoways:• as an Enabler by providing high

performance robustness that allowschanges to engine design andaftertreatment technology withoutimpacting fuel economy;

• as a Direct Contributor throughformulating changes which maximisefuel economy.

Both of these roles are interlinked andensuring the right balance ofcomponents (additive chemistry, viscositymodifier and base oils) are selected andtailored for each application will beessential to achieve optimum fueleconomy improvement.

The value in fuel economyAs engine oils are developed which

The role of engine oils in improving fuel economy

L U B E M A G A Z I N E N o . 9 5 F E B R U A R Y 2 0 1 0 29

provide greater levels of fuel economyimprovement they will be enabling costsavings for OEMs and vehicle operators.Since Euro 4, new aftertreatmentcompatible engine oil technology hasdelivered greater value by helping ensureemissions compliance through theprotection of advanced aftertreatmentsystems. The next generation of fuelefficient engine oil technology willprovide greater value, often directlyquantifiable as cost savings or theavoidance of fines as illustrated in theexamples below. For further informationon changes in the European engine oilmarket see www.lubrizol.com\ACEA2008

Example 1: CO2 emissions legislationfor passenger carsIn 2007 the EU reported the average CO2

emissions of the European passenger carfleet had reduced from 186 g/km in1995 to 158 g/km (figure 1). From 2012to 2015, it is proposed that a system offines is phased in. These will range from€5 to €95 per gram of CO2 a vehicleemits above 130 g/km. It is alsoproposed that the CO2 limit above whichfines are payable is reduced further, to95 g/km, from 2020. As an example, ifthe fines payable in 2015 were appliedto the cars sold in 2006, the total finespayable would have exceed €34 billion.

Many passenger car engine oils arealready formulated to improve fueleconomy. However, if new engine oiltechnology were developed thatprovided an additional 1% improvementthis would save an average of 1.5 g/kmof CO2, avoiding €143 per vehicle in CO2

fines. To achieve this level ofimprovement will require a newgeneration of engine oil technology thatis designed to maximise fuel economyimprovement whilst maintainingdurability and aftertreatment systemprotection.

Example 2: Cost of operation forheavy duty diesel trucks and busesThe use of an engine oil which providesan improvement in fuel economycompared to the engine oils in use todaycan deliver significant savings for a fleetoperator. A 1% improvement in fueleconomy alone would result in over €1.2billion3 in fuel cost savings and areduction of over 3 million MT of CO2

emissions per year for the EU bus andtruck fleet. The savings differ byapplication as illustrated in figure 2 andbelow:

• For a heavy duty truck covering150,000km per year. This could resultin fuel savings of up to €5,403 and areduction in CO2 emissions of up to1.4 MT per truck per year.

• For a bus covering 70,000km per year.This could result in fuel savings of upto €2,803 and a reduction in CO2

emissions of up to 0.75 MT per busper year.

To achieve this level of improvement willrequire a new generation of engine oiltechnology that is designed to maximisefuel economy improvement whilstmaintaining durability and aftertreatmentsystem protection.

NOTES1 ANFAC European Car Parc Study,

2007 and ACEA2 The term “Low HTHS” is commonly

used to refer to engine oils with ahigh temperature high shear rate ofless than 3.5cP by CEC L-036-90.

3 AA Roadwatch report on diesel fuelretail pricing across the EU15, January2009

Mike McCabe,Lubrizol Ltd

LINKwww.lubrizol.com