Cheap Oil

If you look on the TPS site for the MSDS sheet for Long Life 3
http://quantum.thetradepartsspecialists.co.uk/uploads/72/ZGB115QLB00500_SDS.pdf
Look at the SDS number, AFAIK a unique number associated with the product.
SDS Number: 463194
If you Google this number, you find only 2 real hits, the MSDS for Quantum Long Life 3 and this
http://msdspds.castrol.com/ussds/am...file/048305Castrol SLX Longlife III 5W-30.pdf
The MSDS for Castrol SLX Longlife III 5W-30 .
Seems a bit of a coincidence to me.
The supplier is Nordic Lubricants A/S which is a wholly supplied subsidiary of BP who own Castrol.
There are likely to be small differences with LL3 and the premium products such as Castrol Edge FST but personally I have no issues using LL3 in my car.

There are small differences in the physical properties but the date of the documents is slightly different. I see no reason to think that Quantum LL3 is not made by Castrol, there is just so much evidence to support this. Even the fact that TPS only stock either Quantum or Castrol oil. They are dealing with just the one supplier, there is probably more mark up on the Castrol products.
Did a bit more searching and found this
http://msdspds.castrol.com/ussds/am...369Quantum Longlife III Engine Oil 5W-30.pdf
The MSDS for Quantum Long life 3 oil made by Castrol.
The physical properties are identical to Castrol SLX Longlife III 5W-30 .