Change it every 7500 miles or 1 year, whichever comes first. Change it more often if you encounter any of these conditions:
-- extensive idling on a regular basis
-- severely dusty driving conditions
-- mostly stop/go city driving (70% or more of miles)
-- frequent short trips (less than 2 miles/5 minutes)
-- hauling, towing or other severe service
So if you read my post then I check majority of those boxes. So back to the original question.. Should i go 3,750 even though I use full synthetic.
Yes, the problem is fuel dilution and soot. Synthetic doesn't help that.
I'm going out on my limb. I'd change it just like the severe service recommendation in your owner's manual. 3750 miles.
Actually, I'd do a nice round 3k OCI. I don't get the logic behind someone (not talking about you) trying to save $25-50 a year
on a $5,000-$40,000 car/truck by stretching out an OCI. If you don't have the money that's one thing. Maybe I was an alcoholic
for too long and I lost too many brain cells. IDK???
My wife's current car has about the same pattern of use and I change it with synthetic every 3k. Her last car, which we just sold at 199k, starting using oil, dripping oil, etc at 145k. I changed her oil every 5k which was about once a year. I am convinced I should
have changed it more often. I guess time will tell as I have adjusted my future OCI's.
IF you are someone that doesn't keep cars too long, it probably won't matter as it may be someone else's problem.