Is Dexos 2 oil necessary

[andyp]

One of our  local garages has a reputation as the safest MOT inspection garage in town and I am reluctant to change it. However they do not use Dexos 2, they use C3 fully synthetic.
I only do 10,000 per year these days but I am happy to do an annual oil change is enough for me, although the service manual says that a Dexos 2 service interval is 2 years.

To confuse things further the local Vauxhall dealer service centre recommend a yearly, not 2 yearly, service even for Dexos 2, and also informed me that Dexos 2 is fully synthetic. All other info I can find says it is semi synthetic.

Hi so long as the oil they are using meets all the spec of dexos , I can not see a problem, I have allways used aftermarket oil in all cars I have owned from BMW to Vauxhall with no problems, there are lots of youtube videos on oil testing watch them to put your mind at rest, I would trust the local independent with a good reputation to know what they are doing.