Herb wrote:This thread is hilarious.
Instead of asking why a cheap oil is cheap, ask why an expensive oil is expensive. How much of it is for marketing?
I wrote to Opie oils yesterday, and got a very interesting reply.
Worth a read.
There are reasons why budget oils are not the best option.
For example, there are three different types of synthetic basestocks, so there can be a big difference between the basic make up of oils, even though the labels essentially say the same thing.
http://www.opieoils.co.uk/pdfs/tech-art ... ptions.pdf
As you can see from that, oils labelled as synthetic can be mineral oil derived, proper genuine synthetics or ester based synthetics, all of which affect the price. Shell have thrown a spanner in the works with that classification as they now use a different method to produce the group 3 oils, which uses gas as the raw material and reduces the level of impurities in the finished product, so in theory the Shell group 3 basestock is pretty good stuff.
Another way of affecting the price of an oil is to alter the additive package.
http://www.opieoils.co.uk/pdfs/tech-art ... ackage.pdf
The additive pack is a very important part of the oil and can greatly affect the oils properties, but it can be reduced in quality or quantity to reduce the production costs. That can mean that the oil will not last as long or work as well.
Quality control affects the price and quality, the more samples are tested during production, the more it costs, but the more likely it is to be what it says on the label. Some cheap oils have been found to be well out of grade (one of the worst I've heard of was something that was supposed to be a 5w-40 was actually a 20w-40).
Paying for the name is one way of looking at it, the other way is reassurance due to a trusted brand. Yes, Castrol, Shell and Mobil can be expensive, but everyone knows those brands and very few people have ever had problems with them. Some of the smaller brands are less well known and people don't know how good their products will be. That's not to say they won't be fine, but paying an extra few quid for peace of mind can be worth it.
Actual manufacturer approvals can cost a lot of money and that adds to the price of an oil, so a lot of manufacturers sell oils as 'meets the requirements of XXXX' or 'Can be used where XXXX is specified'. You then have to trust the oil manufacturer that the oil is actually suitable for the application, rather than the oil being approved. Don't risk that with cars under warranty, pretty much all manufacturers will void a warranty if the wrong oil is used. Some dealerships are testing the oil before they look at engine issues now, as if the oil is incorrect, they may be able to get out of doing the work.