Synthetic or Non Synthetic? What do the dealers usually use?

houkouonchi

I always had them put ester oil in my 370z but i recently had a bunch of work done and an oil leak and they had to put oil in. The problem is that lookuing at the printout ester was not used as it just says:

5w30 Oil, Motor

The problem is the oil level is a little low. I have a feeling its cause they only put 5 qts in when it should be atleast 5.5 because I have an oil cooler. Its almost down to the L. It is also possible its still leaking or burning oil. I want to put more oil in it to test that theory (I just got my car back a day or two ago).

Anyone know what the dealer would normally put in a 370? Regular non-synthetic or synthetic? I am guessing they would just put regular non-synthetic in to save money in warranty repair things like this?

If I add synthetic to it is that a problem (mixing the types)? I tried calling the dealer a bit ago but I can't reach anyone in the service department. I called yesterday too but it was kind of unclear. They said they use mobile 1 and he verified it wasn't ester if it doesn't say that on the printout but he couldn't give me a strait answer on synthetic vs non-synthetic.