PPD Solutions for GF-5 from the developers of ROBO

From GF-4 to GF-5

ROBO Test Equipment

The introduction of GF-4 altered the composition of engine oils in a profound way, with chemical limits on sulfur and phosphorous forcing changes in formulation practices. In addition, for the first time a criterion for the low temperature testing of used engine oils was introduced into a lubricant specification. RohMax, the world leader in pour point depressants (PPDs), was there with the technology, expertise, and insight to provide tailored solutions to customers’ low temperature needs in this new formulating environment. Specifically, RohMax created the first PPD for GF-4 formulations with the aid of an in-house screening test developed to evaluate the effectiveness of PPDs in used oils.

ROBO Test Equipment

GF-5 is now a reality, and once again RohMax led the way in creating the PPD technologies required to meet or exceed the low temperature requirements of this new specification. But this is only part of the RohMax GF-5 story. From its in-house used oil screening test, RohMax has developed the ROBO test method to fully evaluate the effect of PPDs on the low temperature properties of used oils. The test replaces an expensive industry engine test with an inexpensive bench test so that formulators can maintain their traditional flexibility in PPD selection. Due to RohMax’ efforts, the ROBO test is now an ASTM test method and a part of the GF-5 test line-up.

Uniquely prepared to provide PPD solutions for GF-5

RohMax is uniquely prepared to provide PPD solutions for GF-5. We have a PPD development model that enables quick identification of optimum PPD compositions for both fresh and aged oils. We are willing to customize PPD solutions. We have been able to provide universal PPD solutions covering multiple base stocks, viscosity grades, VIIs and DI packages with limited concessions in performance or treat rates. We work closely with our customers to understand what drives their PPD selection: be it performance claims, treat rate concerns, premium grades or supply chain flexibility. Our Technology Center in Horsham has extensive low temperature testing capabilities as well as 6 ROBO units for aged oil generation. We identify the best candidate PPD and then provide treat rate performance profiles for each oil and each low temperature test - enabling the customer to select their optimum treat rate for each oil. We run programs for 1 oil or 40 oils. We are currently running GF-5 programs.

GF-5 PPD Program Details

ILSAC Oils: Fresh and aged oil must be studied. First, the RohMax PPD model will be used to select candidate PPDs. ASTM D97 PP, ASTM D4684 MRV TP-1, and ASTM D5133 Scanning Brookfield tests will be run on all oils with the candidate PPDs added at one low treat rate. With this data, the PPD choices can be narrowed down and/or a new PPD composition can be proposed. Then, the oils will be aged by ROBO without a PPD present. Again, we will use the RohMax PPD model to further narrow PPD choices or synthesize new compositions. The narrowed down candidate PPD choices will be tested in the aged oil in MRV TP-1 at the SAE grade or 5 degrees warmer based on the CCS viscosity. The best candidate PPDs will be tested in fresh and aged oils at several treat rates to generate a treat rate profile for each low temperature, low shear test.

The ASTM ROBO Method

ASTM ROBO Method
D7528, Standard Test Method for Bench Oxidation of Engine Oils by ROBO Apparatus
Published in June 2009

This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products and Lubricants and is the direct responsibility of Subcommittee D02.0B.07 on Development and Surveillance of Bench Test Methods.

An interlaboratory round robin was run with seven samples tested in seven laboratories on ten test rigs. The results were analyzed and used to generate the precision statement for the method which passed its Subcommittee ballot in December 2008 and its main D02 Committee ballot in April 2009.

A copy of the new standard is available on:

D7528 - Standard Test Method for Bench Oxidation of Engine Oils by ROBO Apparatus

The ROBO test is also being monitored by the ASTM Test Monitoring Center from which reference oils and test rig certification may be obtained.