My only concern is how it'll affect the engine
The effect on engine wear, efficiency of operation, and service life (i.e., engine service life) due to a switch to a blended synthetic oil from a full synthetic oil is probably not even "measurable". Full synthetics will be less subject to degradation and evaporation during the oil service interval, though. But, you would need complex test instruments to even pick up the difference; it is that small. And, even if there is a "difference", whether the differences are meaningful or not, in terms of engine life, is yet another matter. If your Owner’s Manual recommends "synthetic oil", and uses that term alone (i.e., does not refer to "blends") I would recommend you use "100% synthetic oil" and not a blend. If it were my car I would use the most expensive, highest rated synthetic oil I could find. Oil does make a difference and even more important, drain intervals make a difference. Changing your oil removes dirt and contaminants and newer cars with all sort of oil actuated mechanisms, such as variable valve timing, need CLEAN oil. YourMechanic offers oil and filter changes during mobile visits and you should certainly avail yourself of that service as the cost is lower and the service is much more personalized. If you have additional concerns, don’t hesitate to re-contact us.
Have a car question? Get free advice from our top-rated mechanics.