[n_mol]

Hi. I bought my new car in September of last year, and it obviously came with the oil that the company (vauxhall) put it. But I have topped it up with a different make of oil. This should be OK shouldn't it ?

[labman]

I like to pick a product and stick with it. Cars survive a lot of oil mixing. I seriously doubt there would be problems from a small amount of make up oil. If you have had to add several quarts, I would be asking the dealer why.

Check your owner's manual. Many manufactures are pushing severe driving with relatively short oil change intervals. You may be approaching the first one. Try to decide who and where the oil is going to be changed, and plan to stick to the same thing every time. The only major brand I would warn you away from is Fram filters. Their quality is shockingly poor compared to even the cheapest brands.