Hi,
VW, Audi and Castrol in 2002 completed extensive real world testing of long life oils over five years including three years in England. Tests involved low use cars not reaching operating temperature at each drive cycle and high speed Motorway type operations covering an annual distance each month. It was designed to confirm the 30kkms (petrol engines) and 50kkms (diesel engines) oil drain intervals
VW503 petrol and VW506 quality standards resulted then. VW506.01 was conceived then too after wear tests measured at one millionth of a millimeter per hour confirmed their requirements were met.
Castrol's SLX Longlife2 was the end result
Time has moved on relentlessly since
Regards
Doug
VW, Audi and Castrol in 2002 completed extensive real world testing of long life oils over five years including three years in England. Tests involved low use cars not reaching operating temperature at each drive cycle and high speed Motorway type operations covering an annual distance each month. It was designed to confirm the 30kkms (petrol engines) and 50kkms (diesel engines) oil drain intervals
VW503 petrol and VW506 quality standards resulted then. VW506.01 was conceived then too after wear tests measured at one millionth of a millimeter per hour confirmed their requirements were met.
Castrol's SLX Longlife2 was the end result
Time has moved on relentlessly since
Regards
Doug