First, you should know that the 'quicky' places have been caught outright LYING to customers about services their cars 'need' according to the 'factory specs' even though there might not be ANY such specs.
If you NISSAN dealer says the car takes regular dino oil, if NISSAN FACTORY put dino oil in the car from the FACTORY, then your car will run fine on dino oil. Modern regular oil is 10x better than it was 20 years ago and will be able to run your car just fine, whether 2.5 or 3.5 regardless even over 3000-5000 miles depending on usage and conditions.
The quicky change place basically lied to you about the car being
Now does that mean you shouldn't run synth? No. Most cars may see some benefit (and others depending on age, shouldn't run) but it's all dependent on factors I have no real understanding of. However I have read that once you go synth, you should not go back to regular oil as it has something to do with the way synth oil affects the seals and gaskets in the engine, and going back to regular can cause gasket failures or something. I'd research that more if I were you and plan to go back to regular oil.
So now that they suckered you into getting your first synth oil change for oh, look, $35 bucks (instead of $20-$25 for regular), I'm sure THEY'RE happy they made the extra buck. The question is how do you "feel" (again, may be true, or might be a placebo affect) about the oil and was your car giving you any trouble before? If not, well lesson learned.
In case you're wondering what 'scams' they have been caught for (I'm talking Jiffy Lube, Firestone, Kwik Car, etc.) an undercover reporter took in his Accord for oil change and was basically 'scammed' into getting a full engine flush (which BTW was supposed "Honda" recommended....). Most customers who got such engine 'flushes' usually had their engine quit soon down the line. I'm not saying these processes are bad, I'm saying these processes are best left to your DEALER so if the screw up, it's on THEM, not you for going outside the factory recommended service.
TLDR; Screw the quicky places and stick to the dealer. They half a** their work sometimes, from personal experience, and are not worth the often extra cost (but, but, they vacuum!) and risk of damaging your car based on their 'recommended' services which amount to nothing more than upselling you with "would you like extra grease with that burger."
Not to be a downer or beating you up, just thought I'd let you know what's up.
